Rugged Environment AC-DC Converters >100 Watt 500 Watt AC-DC Converters T Series T Series Input to output isolation Single output * Universal AC input range * DC output voltage for 24 and 48 V loads * Battery charging for 24, 36, 48 V batteries with remote temperature control * Telecom rectifier applications * Immune to transients and disturbances according to VDE 160 and IEC/EN 61000-4-2,-3,-4,-5,-6 * 4000 V AC input to output electric strength test * Very high efficiency, typically 93% * Power factor >0.96, harmonics <IEC/EN 61000-3-2, low RFI * No inrush current, hot plug-in capability * High power density, 210 W/dm3, rugged mechanical design * Very compact 19" cassette (28 TE, 3 U, 160 mm), 111 4.4" 3U Safety according to IEC/EN 60950 LGA 141 5.6" 28 TE C 168 6.6" Summary The T series of converters are electrically isolated AC-DC converters with an output power of up to 550 W. For higher power requirements several units may be connected in parallel. The input of the T units is ideally adapted to the mains: Full power factor correction, no inrush current, low RFI level and high transient and surge immunity are key design features. The T units behave similar to a resistive load. The L-input provides a universal AC-input range from 85...255 V AC. It is the preferred type for 230 V mains, whereas the U-input range is optimized for 110/120 V mains. The output delivers an electrically isolated Safety Extra Low Voltage (SELV) and is short-circuit and no-load proof. Depending on the type, two output characteristics are available, intended either for rectifier applications or for battery charging purposes. The latter types can be integrated into systems where the output voltage is backed-up by batteries. The float charge of the battery can be set by a cell voltage selector switch according to the battery type used. Moreover these units feature a temperature sensor input to improve the life expectancy of the battery. The rectifier types suit for DC-bus applications at constant voltage. As the output voltage is SELV, even electrically non isolated switching regulators such as the Melcher PSR types may be connected to the T output. The T 1701 types are especially optimized to build distributed power systems together with the Melcher CQ-series DC-DC converters as the signalling capabilities of both families are matched. Distributed power systems have as one advantage less power loss over load lines and fewer regulation problems. Melcher offers also backplanes for fast and simple set-up of 19" rack systems with T units (see chapter: Back Planes). Table of Contents Page Page Summary .......................................................................... 1 Type Survey and Key Data .............................................. 2 Type Key .......................................................................... 2 Sensor Type Key .............................................................. 3 Functional Description ...................................................... 4 Electrical Input Data ......................................................... 5 Electrical Output Data of the Rectifier Version ................. 7 Electrical Output Data of Battery Charger Version ......... 10 Control Features of the Battery Charger Version ........... 12 Temperature Sensors ..................................................... 15 Functional Features ....................................................... 16 Auxilliary Functions ........................................................ 21 Electromagnetic Compatibility (EMC) ............................ 25 Immunity to Environmental Conditions ........................... 26 Environmental Conditions .............................................. 27 Mechanical Data ............................................................ 28 Safety and Installation Instructions ................................ 30 Description of Options .................................................... 33 Accessories .................................................................... 33 MELCHER The Power Partners. Edition 4/4.99 1/33 T Series AC-DC Converters >100 Watt Rugged Environment Type Survey and Key Data Table 1: Type Survey (All typical values at 20 C) Output voltage 1 Uo set at Ui nom, /2 Io nom [V DC] Io nom [A] 24.25 16 25.25...27.25...28.25 14.5 54.5 10 2 3 4 5 6 Input voltage range and efficiency min [%] Ui min...Ui max 70...140 V AC 1 Ui min...Ui max 85...255 V AC Options min [%] UT 1201-7 2, 4 91 LT 1201-7 2, 6 91 UT 1240-7Z 4, 3 91 LT 1240-7Z 6, 3 92 UT 1701-7 5 92 LT 1701-7 6 93 1702-7 2, 6 48 11 - - LT 50.5...54.5...56.5 10 UT 1740-7Z 5, 3 92 LT 1740-7Z 6, 3 93 - 1840-7Z 3, 6 91 37.9...40.9...42.4 1 Output current 11 - LT 1 D B1 93 Efficiency measured at Ui nom and Io nom. Instead of output power limitation, output current limitation. Output voltage range controlled by input Ucr , remote temperature sensor and cell voltage selector switch. Reduced output power for Ui = 70...95 V AC. See Output Power Limitation. Reduced output power for Ui = 70...100 V AC. See Output Power Limitation. Reduced output power for Ui = 85...155 V AC. See Output Power Limitation. Type Key Type Key Input voltage range Ui 70...140 V, 47...63 Hz ................................ U 85...255 V, 47...63 Hz ................................. L Series ............................................................................... T Number of outputs: ........................................................... 1 Output Uo set 24, 27.25 V .................................................. 2 48, 54.5 V .................................................... 7 40.9 V .......................................................... 8 Recifier version .................................... 01, 02 Battery charger version .............................. 40 Other voltages .................................... 00...99 Ambient temperature range TA -25...71C .................................................. -7 Customer specific ................................ -0...-6 Auxiliary functions and options Remote bus voltage monitoring (option) ..... D Cell voltage selector switch ......................... Z Input fuse externally accessible ................... F Baseplate (option) ...................................... B1 L T 1 7 40 -7 D Z F B1 3 4 1 2 1 See also: Description of Options as well as data sheet: Back Planes for the T Series. Only for T 1240/1740/1840 3 No input for remote temperature sensor 4 With input for remote temperature sensor 2 Example: LT 1740-7Z: AC-DC converter, input voltage range 85...255 Vrms, single output 50.5...56.5 V DC, 10 A, operational ambient temperature -25...71C, with cell voltage selector switch. MELCHER The Power Partners. Edition 4/4.99 2/33 Rugged Environment AC-DC Converters >100 Watt T Series Sensor Type Key Type Key Series ............................................................................... S 1 Battery nominal voltage 24 V ........................................................... 24 36 V ........................................................... 36 48 V ........................................................... 48 Cell voltage (at 20C) 2.23 V ..................................................... 2.23 2.27 V ..................................................... 2.27 2 Temperature coefficient -3.0 mV/K/cell ........................................... 30 -3.5 mV/K/cell ........................................... 35 -4.0 mV/K/cell ........................................... 40 -4.5 mV/K/cell ........................................... 45 other temperature coefficients on request ..... Cable length (2 m) .......................................................... 02 1 2 Only for LT 1240/1740/1840 For units without cell voltage selector switch MELCHER The Power Partners. Edition 4/4.99 3/33 S 48 - 2.23 - 30 - 02 T Series AC-DC Converters >100 Watt Rugged Environment Functional Description The T unit is a primary controlled AC-DC converter with a constant switching frequency of 65.5 kHz. The power factor corrected single step conversion of the line input voltage to a low output voltage results in extremely high efficiency. The input voltage is fed via input fuse, filter and rectifier to the main transformer. The wideband input filter with small input capacitance generates virtually no inrush current. Transient suppressors protect the unit against high voltage peaks and surges. An auxiliary converter generates an internal supply voltage for the primary control logic. The input voltage waveform is sensed by the primary control logic to allow power factor correction. The main transformer is connected to a rectifier, large output capacitors and an efficient output filter which ensures low output ripple and spikes and provides the necessary hold-up time. The output voltage is fed back to the primary control logic via a signal transformer. System Good and Output voltage OK are each indicated by a green LED, inhibit and T System Failure by a red LED. System Good and Power Down are available as open collector signals at the connector. The threshold level of the Power Down signal can be externally adjusted at the D set input. Test sockets at the front panel allow the measurement of the output voltage. The battery charger version provides additional features to control the output voltage. To set it to different battery float charge voltages, a 16-step selector switch (Z) is standard. A control input for remote output voltage adjustment, by an external temperature sensor is available at the multifunctional inhibit/Ucr control pin. A trim-potentiometer allows fine adjustment of the output voltage. The inhibit signal and the T failure signal are transferred by a second signal transformer (no opto-couplers!). - + 03043 Cy 12 Vo+ 14 Vo+ Output Filter Input Filter N~ 6 Input Filter P~ 4 Input Filter Fuse 16 Hot-plug + NTC 18 Hot-plug - 20 Vo- 8 Cy Cy Cy Auxiliary Converter Cy Cy 22 Vo- 10 24 Sys In Voltage and System Monitor Control Circuit 26 Sys Out 28 i/Ucr 30 D 32 D set Isolation 4 kVrms Z Fig. 1 Block diagram MELCHER The Power Partners. Edition 4/4.99 4/33 P Rugged Environment AC-DC Converters >100 Watt T Series Electrical Input Data General conditions: - TA = 20C Table 2a: Input Data LT types Input LT 12xx Characteristic Conditions min Ui Input voltage range with full output power AC (47...63 Hz) U i red Input voltage range with reduced output power 1 typ max min 155 255 85 155 U i nom Nominal input voltage U i nom, Po nom max min typ 155 255 130 255 Vrms 85 155 85 130 230 230 1.9 2.6 2.2 3 4 4 6 8 8 3 3 Nominal input current Ii L Input current limit Pi 0 No-load input power U i min...U i max, I o = 0 Pi inh Input power when inhibited U i min...U i max, inhibit = low 3 U i nom, Io nom typ LT 18xx 230 I i nom factor 2 LT 17xx Power Input capacitance 3 U i nom t on Switch on delay U i nom, Po nom ui RFI Input RFI level 4 Io = Io nom EN 55014, EN 55011/022 Ui p Input overvoltage protection 5 Ui L Input undervoltage lock-out F Input fuse 5 x 20 mm 6.3 6.3 6.3 A f tr Switching frequency 65.536 65.536 65.536 kHz 96 98 4 98 % 4 400 400 400 B 264 264 75 UT 12xx Characteristic Conditions min Ui Input voltage range with full output power AC (47...63 Hz) U i red Input voltage range with reduced output power 1 typ min 264 Vrms 75 95 140 70 95 4 5 max Unit 100 140 Vrms 70 100 115 115 3.8 5.2 5 6 I i nom Nominal input current Ii L Input current limit Pi 0 No-load input power Ui min...Ui max, I o = 0 6 8 Pi inh Input power when inhibited Ui min...Ui max, inhibit = low 3 3 PF Power factor 2 Ui nom, Io nom Ci Input capacitance 3 Ui nom t on Switch on delay Ui nom, Po nom level 4 Ui nom, Po nom typ 98 V Arms W 98 % 4 4 F 400 400 ms Io = Io nom EN 55014, EN 55011/022 ui RFI Input RFI Ui p Input overvoltage protection 5 Ui L Input undervoltage lock-out F Input fuse 5 x 20 mm 10 10 A f tr Switching frequency 65.536 65.536 kHz B B 165 65 165 65 Vrms V The output power is reduced because of the input current limitation Po Ui [Vrms] IiL [Arms] h Power factor as a function of the input voltage and load as well as harmonic distortion see Power Factor, Harmonics. Inrush current stays factor 10 below ETS 300132-1. 150 kHz...30 MHz: CISPR 11/22/EN 55011/22 class B, 30...300 MHz: CISPR14/EN 55014 In case of overvoltage the unit switches off temporarily, resulting in reduced output power and increased RFI. MELCHER The Power Partners. Edition 4/4.99 5/33 ms B UT 17xx max F 4 B 75 U i nom Nominal input voltage 3 W Ci Input 2 Arms PF Table 2b: Input Data UT types 1 max Unit T Series AC-DC Converters >100 Watt Rugged Environment Input Fuse Efficiency An input fuse (5 x 20 mm) fitted in the line (P) path mounted inside the converter protects the module against severe defects. (See also: Safety and Installation Instructions.) For applications where the fuse should be accessible: see Option F. The extremely high efficiency of the T series is achieved by using a single step power factor corrected converter topology together with the most advanced technology in power conversion. Table 3: Fuse Type Series Schurter type Part number LT SP F 6.3 A, 250 V 0001.1012 UT SPT 10 A, 250 V 0001.2514 It allows a very compact design in a fully enclosed case without forced cooling. Eff. 0.96 04024 0.94 0.92 Inrush Current 0.90 The T units operate with 4 F input capacitance resulting in a low peak current of short duration when the unit is connected to the mains. During switch on the input current can rise up to the input current limit Ii L. As a direct result of the low and short inrush current and controlled charging procedure of the output capacitors, the unit can be hot plugged to the mains causing only negligible disturbances. The LT inrush current is a factor 10 smaller than defined in the ETS 300 132-1 standard for Telecom Systems. However the unit should be plugged-in smoothly giving time to the output capacitors to be charged. 0.88 0.86 0.84 0.82 0.80 0 2 4 6 U i = 110 Vrms 8 10 12 14 U i = 230 Vrms 16 Io [A] Fig. 3 Efficiency versus load of LT 1701 Input Under-/Overvoltage Lock-Out If the specified input voltage range U i is exceeded, the unit stops operation temporarily resulting in reduced output power and increased RFI. The input is protected by varistors. Continuous overvoltage will destroy the unit. 3.0 If the sinusoidal input voltage stays below the input undervoltage lock-out threshold U i, the unit will be inhibited. 2.5 Power Factor, Harmonics 2.0 Power factor correction is achieved by controlling the input current waveform synchronously with the input voltage waveform. The power factor control is active in all operating conditions (voltage regulation, output power limitation, current limitation). The power factor control also works with different input voltage waveforms and frequencies. Operation at frequencies above 60 Hz will result in higher leakage currents. For special applications with different frequencies or non-sinusoidal wave forms, please contact Melcher. 1.5 PF 04023 1.00 0.98 Limit class D according to IEC/EN 61000-3-2 1.0 0.5 0 Harm. 3 5 7 9 11 13 15 17 19 Fig. 4 Harmonic distortion at input LT 1740-7Z, Ui = Uinom, Io = Io nom 0.96 I i [mA/W] 3.5 0.94 3.0 0.92 04026 Ii [mA/W] 3.5 04025 Limit class D according to IEC/EN 61000-3-2 2.5 0.90 2.0 0.88 0.86 1.5 0.84 1.0 0.82 Io [A] 0.80 0 2 4 6 8 10 UT 1740-7Z at U i = 110 Vrms LT 1740-7Z at U i = 230 Vrms Fig. 2 Power factor MELCHER The Power Partners. 12 14 16 0.5 0 3 5 7 9 11 13 15 17 19 Fig. 5 Harmonic distortion at input UT 1740-7Z, Ui = Uinom, Io = Io nom Edition 4/4.99 6/33 Harm. Rugged Environment AC-DC Converters >100 Watt T Series Electrical Output Data of the Rectifier Version General conditions: - TA = 20C, unless TC is specified. - Ui = Ui nom, f = 50 Hz Table 4: Output data Output LT/UT 1201 Characteristic Conditions Uo set U i nom Io = 0.5 * Io nom Output voltage adjustment min 3 4 5 6 min typ max Unit 48.0 V 24.0 24.5 54.25 54.75 47.75 48.25 23.35 24.95 52.8 55.8 49.3 32.5 59.3 Uo L Output Overvoltage protection by electronic inhibit a Uo Temperature coefficient of output voltage -5 -5 -5 mV/K Io nom Nominal output current 16 10 11 A limit 2 Uo = 20 V 18 4 14.5 14.5 U i nom 400 550 550 Current Po L Output power limit 2 uo Output voltage noise Low frequency TC fixed value Io nom IEC/EN 61204 5 BW = 20 MHz 0.85 40 Total 2 typ max 54.5 Output voltage over input voltage (See fig.: Typical output voltage verus input voltage and output current.) Io L U i min...U i max Io = 0.01 * Io nom ...Io nom LT 1702 Uo Switching freq. 1 min 24.25 Uo set tol Uo setting tolerance and1 load typ max LT/UT 1701 regulation 1 46.3 59.3 1.0 40 W 1.05 40 Vpp mVpp 0.9 1.05 1.1 Vpp V DUo I Static load (See fig.: Typical output voltage versus input voltage and output current.) Io = 0.01 * Io nom ...Io nom 0.6 1.2 1.2 DUo U Static line regulation (See: Typical output voltage versus input voltage and output current.) Ui = Ui min...Ui max Io nom 0.3 0.8 0.8 uo d td Dynamic load regulation 3 Voltage deviation UI nom (See fig.: Dynamic chaIo nom 1/10 Io nom Recovery time racteristic under varying IEC/EN 61204 6 load conditions.) Co Internal output capacitance 1.7 2.2 2.2 0.25 0.25 0.25 s 86 41 41 mF Output voltage decreases with rising output current because of output voltage slope for automatic current sharing capability. Due to the large output capacitors the maximum transient value can be much higher. Deviation limited by output overvoltage protection. No power limitation, but current limitation. See: Technical Information: Measuring and Testing. See fig.: Dynamic load regulation. Output Characteristics (Recifier Version) - Output voltage regulation - Output power limitation - Output current limitation Output voltage regulation Uo [V] 60 Output power limitation Output current limitation 05045 The T 1701/1702 types can be operated in 3 different modes: 50 - In output voltage regulation mode the T unit can be operated within the full temperature range -25...71C. - In output power or current limitation mode the max. ambient temperature TA should not exceed 65C with free air convection cooling. 40 30 20 10 Fig. 6 Output characteristics LT 1701-7 MELCHER The Power Partners. 0 0 Edition 4/4.99 7/33 2 4 6 Ui = 110 Vrms 8 10 12 14 Ui = 230 Vrms 16 Io [A] T Series AC-DC Converters >100 Watt Rugged Environment Output voltage regulation (Rectifier Version) Output current limitation (Rectifier Version) The output voltage of rectifier models is adjusted to a fixed value Uo set. It relates to the output current and the input voltage which ensures automatic current sharing operation without further precautions when several units are connected in parallel. Rising output current and falling input voltage lead to a decrease of the output voltage, according to the formula: The output of the T units is fully protected against continuous short circuit. The maximum constant current is limitted to Io L (see table: Electrical output data). As the LEDs indicating the system status are driven from the output voltage, in short circuit mode all LEDs switch off. Uo [V] 54.5 48 Uo Uo set tol + (0.5 - Io/Ionom) * DUo l + (Ui - Ui nom)/100 V * DUo U Uo 04027 38 05081 2% 1% Uo set 0 Io [A] 0 -1% Load regulation -2% I o /Io nom 0.01 0.5 10 11 14.5 Fig. 8 Typical output voltage versus output current of UT/LT 1701/ 1702 1 Uo [V] Fig. 7 Typical output voltage versus input voltage and output current of LT 1701 05048 24 Note: Units with different output voltage regulation characteristics (e.g. less output current dependency) are available upon request. 16 Especially for power systems with an output voltage of 48V and more, the rectifier models T 1701/1702 feature an output power limitation mode. The output power is kept constant down to an output voltage of approximately 38 V. This provides improved start-up capabilities of power systems including switched mode power supplies connected to the DC bus (e.g. Melcher CQ units). At maximum load there is no need for a special start-up procedure. The maximum input current is limited to I i L. At lower input voltage Ui red the maximum output power is limited to: Po h * Ui red * Ii L (h = efficiency 90%) The T 1201 types have no output power limitation characteristic. Output Overvoltage Protection (Rectifier Version) A slight output voltage overshoot may occur at turn on, inhibit release or during fast load changes. A second, independent control loop interrupts operation above Uo L indicated by the red LED. The output voltage remains below 60 V (SELV) under all operating conditions. Note: There is no specific built-in protection against externally applied overvoltages or transient sources like e.g. motors. Never apply voltages >60 V (>35 V) to the output. Otherwise the unit may be damaged. MELCHER The Power Partners. Io [A] 0 Output power limitation (Rectifier Version) Fig. 9 Typical output voltage versus output current of UT/LT 1201 Hold-up Time (Rectifier Version) The hold-up time depends upon the output voltage at the time of failure, the minimum acceptable output voltage and the load according to the following formula: Uo2 - Uo2 min u thold = ------------ * (Co + Cext) 2 * Po where: Uo Uo min u Po Co Cext = Output voltage at the moment of mains failure = Minimum acceptable output voltage = Average output power during hold up time = Internal output capacitance = External output capacitance (e.g. on backplane) Examples of t hold are given in the table below: Table 5: Hold-up time t hold for T1701 Uo = 54 V Po [W] 46 V Uo min u 43 V 40 V 38 V 100 200 300 400 500 550 164 82 55 41 33 30 219 109 73 55 44 40 302 151 101 75 60 55 Edition 4/4.99 8/33 270 135 90 67 54 49 Unit ms Rugged Environment AC-DC Converters >100 Watt U mains failure Uo 05049 Uo T Series 05051 DUo I low load Uo 10% DUo d Ut DUod heavy load Uo min u td t t warning time 1 0.9 t hold Fig. 10 Hold up and warning time with power down output signal. The table: Hold up time also gives information about the warning time of the power down signal. If for example the threshold level Ut of the power down signal is set to 43 V and the minimum acceptable voltage of the load is 38 V the time between the activation of the power down signal and the switch-off of the load (550 W) will be 15 ms (55 ms 40 ms). Pulse Loading (Rectifier Version) To prevent an overload of the output and filter capacitors the superimposed AC ripple current at the output should be limited as shown below. For high current pulse loads external capacitors are recommended. For other pulse loads than stated in the figure below, e.g. Ui < Ui nom, Io > Io nom, please contact Melcher. Sinusoidal ripple current Io PL [Arms] Io /Io nom 05050 0.1 t Fig. 12 Dynamic characteristics under varying load conditions (see: Electrical Output Data) Inhibit input (Rectifier Version) The rectifier versions are equipped with the inhibit function only. (The Ucr remote control is used with the battery charger version.) The unit is enabled by a logic high signal and disabled by a logic low signal. This input is TTL/CMOS compatible, a resistor <50 disables the unit, a resistor >30 k enables it. The switch-on time tr of the unit, i.e. the time delay between powering until the full output power is available, is typically 100 ms. The hold up time at the output after inhibiting depends on the load, the internal capacitance of the unit and additional capacitance on the DC bus. The inhibit input is protected against DC overvoltage up to 60 V. 15 Ui = Ui nom Average output current = Io nom 10 5 06116 P~ 4 Vo+ 12 i/Ucr 28 TC = 50C U inh TC = TC max 0 I inh N~ 6 T1000 Vo- 22 fPL [Hz] 50 100 1k 10 k Fig. 11 Maximum allowable AC ripple output current superimposed on the average output current Io nom with LT 1701 unit. Fig. 13 Inhibit signal connection Table 6: Characteristics of the inhibit signal Characteristics Uinh Inhibit voltage Conditions min Uo = on Ui min...Ui max 2.5 TC min...TC max Rinh Resistance Uo = on to Vo- 30 Uinh Inhibit voltage Uo = off typ max 60 Switch-on time Ui nom until full power avail. Pinh Input power with inhibited unit MELCHER The Power Partners. Edition 4/4.99 9/33 V k -0.7 Rinh Resistance Uo = off tr Unit 0.4 V 50 100 ms 3 W T Series AC-DC Converters >100 Watt Rugged Environment Electrical Output Data of Battery Charger Version General conditions: - TA = 20C, unless TC is specified. - Ui = Ui nom, f = 50 Hz Table 7: Output data Output LT/UT 1240 Characteristic Conditions Uo set Output voltage adjustment 1 Uo set tol Uo setting tolerance 1 range 2 Uo range Output voltage Uo Output voltage over input voltage and load 3, 1 (See fig.: Typical output voltage versus input voltage and output current.) min Ui nom Io = 0.5 * Io nom a Uo Temperature coefficient of output voltage Io nom Nominal output current Current Po L Output power limit 5 uo Output voltage noise Switching freq. 25.25 28.25 50.5 56.5 37.9 42.4 26.8 27.6 53.8 55.0 40.3 41.3 26.9 27.65 54.0 55.1 TC fixed value Io nom IEC/EN 61204 7 BW = 20 MHz 32.5 59.3 48.4 -3 -3 -3 mV/K 14.5 10 11 A 20 14.5 16 400 550 450 0.71 40 2 3 5 6 7 8 0.85 40 0.75 1.05 0.9 Vpp V Io = 0.01 * Io nom ...Io nom 0.4 0.6 0.6 DUo U Static line regulation (See fig.: Typical output voltage versus input voltage and output current.) Ui = Ui min...Ui max Io nom 0.2 0.35 0.25 uo d Dynamic load regulation6 Voltage (See fig.: Dynamic charac- deviation teristics under varying Recovery time load conditions without battery back-up.) UI nom Io nom 10% Io nom8 IEC/EN 61204 Internal output capacitance 1.6 2.0 2.5 0.2 0.2 0.2 s 86 41 49 mF Output voltage adjustment with Ucr = 9.5 V (2.27 V/cell). Defined by sensor, by remote control and by voltage selector switch. Output voltage decreases with rising output current because of output voltage slope for automatic current sharing capability. Due to the large output capacitors the maximum transient output current can be much higher than Io L , Po L, respectively. Without battery backup. See: Technical Information: Measuring and testing. See fig.: Dynamic load regulation. Load current change for specified output. Other outputs loaded with Io nom. MELCHER The Power Partners. Edition 4/4.99 10/33 Vpp mVpp Static load regulation fig.: Typical output voltage versus input voltage and output current.) C0 1 1.0 40 W DUo I td Unit V 40.93 Total 3 (See max 40.88 54.55 40.83 Ui nom Low frequency min typ 54.5 27.3 54.45 limit 5 Io L LT 1840 27.2 Ui min...Ui max I = 0.01 * Io nom UT o ...Io nom Output overvoltage protection by electronic inhibit min typ max 27.25 LT Uo L typ max LT/UT 1740 Rugged Environment AC-DC Converters >100 Watt Uo Output Characteristics (Battery Charger Version) The battery charger versions T 1240/T 1740/T 1840 series can be operated in 3 different modes: - Output voltage regulation - Output power limitation - Output current limitation Output voltage regulation Output power limitation Output current limitation 05046 1.1% 0.55% Uo set 0 Load regulation -0.9% 05045 Uo [V] 60 T Series I o /Io nom 0.01 50 0.5 1 Fig. 15 Typical output voltage versus input voltage and output current of the LT 1740. 40 Output power limitation (Battery Charger Version) 30 20 10 0 0 2 4 6 Ui = 110 Vrms 8 10 12 14 Ui = 230 Vrms 16 Io [A] All battery charger versions feature an output power limitation mode where the output power is kept constant from 2.35 V/cell (for lead acid batteries) to 1.6 V/cell. This provides better starting up capabilities for power systems including switched mode power supplies connected to the DC bus when the battery is charged. The maximum input current is limited to I i L. At lower input voltage U i red, the maximum output power is limited to: Po h * Ui red * Ii L (h = efficiency 90%) Fig. 14 Output characteristics LT 1740-7 Typical output characteristics according to type - In output voltage regulation mode the T unit can be operated within the full temperature range -25...71C. - In output power or current limitation mode the max. ambient temperature TA should not exceed 65C with free air convection cooling. Uo 06065 28.25 V 26.7 V 25.25 V 19 V Output current limitation (Battery Charger Version) The output of the T units is fully protected against continuous short circuit. The maximum constant current is limitted to Io L (see table: Electrical output data). As the LED indicating the system status are driven from the output voltage, in short circuit all LED`s will switch off. Output voltage regulation (Battery Charger Version) In normal operating mode (unit neither in power limitation nor in current limitation) the output is regulated by a voltage feedback loop. It is adjustet to Uo set and can be set by the cell voltage selector switch to the appropriate float charge voltage of the battery. The battery charger version features a control input (pin 28) for remote output voltage adjustment either by a voltage source, a temperature sensor or an external potential divider (see: Output voltage control via Inhibit/Ucr remote control input). For fine tuning, the units are fitted with a trim potentiometer accessible from the rear of the connector. The output voltage relates to the output current and the input voltage which ensures automatic current sharing operation without further precautions when several units are connected in parallel. An increase in output current and a decrease in input voltage decreases the output voltage, according to the formula: Uo Uo set tol + (0.5 - Io/Io nom) * DUo I + (Ui - Ui nom)/100 V * DUo U Note: Units with different output voltage regulation e.g. less output current dependency are available upon request. MELCHER The Power Partners. Io 0 15 A 20 A Fig. 16 Typical output voltage versus output current of UT/LT 1240 Uo 06066 56.5 V 54.5 V 50.5 V 38 V Io 0 10 A 14.5 A Fig. 17 Typical output voltage versus output current of UT/LT 1740 Uo 40.88 V 06067 42.4 V 37.9 V 28.5 V Io 0 11 A 16 A Fig. 18 Typical output voltage versus output current of LT 1840 Edition 4/4.99 11/33 T Series AC-DC Converters >100 Watt Output Overvoltage Protection (Battery Charger Version) Rugged Environment Dynamic output characteristic A slight output voltage overshoot may occur at turn on, inhibit release or during fast load changes. A second independent control loop interrupts operation above Uo L, indicated by the red LED. The output voltage remains below 60 V (SELV) under all operating conditions. Uo 05051 DUo I Uo 10% DUo d DUod Note: There is no specific built-in protection against externally applied overvoltages or transient sources like e.g. motors. Never apply voltages exceeding Uo L to the output. Otherwise the unit may be damaged. td t Io /Io nom 1 0.9 0.1 t Fig. 19 Dynamic characteristics under varying load conditions (see Electrical output data) without battery back-up. Control Features of the Battery Charger Version According to the recommendations of battery manufacturers, the float charge voltage of a lead acid battery should be temperature compensated. Depending upon the battery type and size, charging with different temperature coefficients may be required. An excessive float charge voltage may damage the battery through overcharging. Most lead acid battery manufacturers recommend cell voltages between 2.23 V and 2.32 V with the nominal cell voltage defined at 20C and temperature coefficients between -3 and -4 mV/K/cell. The value of the negative temperature coefficient, is specified by the temperature sensor. With the cell voltage selector switch Z the required cell voltage can be adjusted at the rear of the unit, making the system flexible to different float charge voltages of battery systems. Cell voltage selector switch Z The standard units T xx40-7Z are equipped with the cell voltage selector switch at the rear side of the unit, which provides an easy way of external adjustment to the recommended float charge voltage for specific battery types. Each switch position allows a step in the output voltage of 10 mV/cell whereby the switch position "0" represents a cell voltage of 2.23 V at 20C and the switch position "C" gives 2.35 V per cell. The cell voltage selector switch fits together with the Melcher 2.23 V temperature sensor. The float charge voltage is set by the switch and the temperature coefficient is specified by the sensor type. 06068 2.23 V 2.24 V 2.25 V 0 2.26 V Where the selector switch Z is not applicable, a cell voltage adjustment can also be provided via the temperature sensor (see: Temperature Sensor). Although it is not recommended, the output voltage can be set to a fixed value without temperature compensation by an external voltage source or a resistive voltage divider at the remote control input (e.g. if the battery temperature shall be controlled by other systems, see: Output voltage control via Inhibit/Ucr remote control input). What needs to be considered with all battery charger types: The final float charge voltage is only reached with a fully loaded battery. Since new batteries directly supplied from the manufacturer are only charged to 70...80% of their capacity, the battery system should be operated for min. 72 h prior to checking the float charge voltage. 2.35 V 4 C 2.27 V 2.28 V 8 2.29 V 2.32 V 2.31 V 2.30 V Fig. 20 Cell voltage selector switch Important: Setting the switch to the correct battery cell voltage is vital for the proper operation of a battery system. Check whether the switch position corresponds to the required battery cell voltage prior to putting a system into operation. Note: Switching to a different cell voltage while the T unit is in operation may cause a small and short distortion of the output voltage. MELCHER The Power Partners. Edition 4/4.99 12/33 Rugged Environment AC-DC Converters >100 Watt T Series Potentiometer for fine tuning T units are fitted with a one-turn potentiometer for fine tuning of the output voltage to within 3.7 0/00 of Uo. The potentiometer is protected by a plastic cover. To adjust the output voltage for improved current sharing or compensa- tion for voltage drops over the load lines, each of the T units in a system should be unplugged and adjusted individually to the same output voltage at equal load; otherwise current sharing may adversely be affected. Output voltage control via Inhibit/Ucr remote control input. Table 8: Characteristics of the inhibit signal Characteristics Conditions min U i min...U i max TC min...TC max 30 k typ max Unit U inh Inhibit voltage U o = on R inh Resistance to Vo- U o = on U inh Inhibit voltage U o = off Rinh Resistance to Vo- U o = off tr Switch on time until full power available U inom 100 ms Pinh Input power at inhibited unit U inom 3 W 2.5 60 V - 0.7 0.4 V 50 The Inhibit/Ucr remote control input at connector pin 28 provides two functions: T 1240 T 1840 T 1740 Uo [V] 28.25 - External adjustment of the output voltage - Inhibiting of the unit A voltage <0.4 V inhibits the output, a voltage >2.5 V enables it. By the Ucr remote control input range of 5.5 V < U cr < 11.5 V, the output voltage Uo set can be adjusted within a range of +3.6% to -7.9%. This feature is optimized to control the float charge of lead acid batteries. Outside of the control range, the sensor monitoring circuit generates a system error signal (see also: System Good). 06069 56.5 42.37 55 27 41 54 53 26 25.25 39 52 50.5 37.85 In the case of a excessively high control voltage, the output is reduced. 3 4 5 5.5 11.5 14 16 Ucr [V] The remote control input is protected against DC overvoltage up to 60 V . Signal high Logic level of System Good signal Signal low 5.3 V 14 V Ucr [V] Fig. 21 Output voltage Uo versus control voltage Ucr, with corresponding system good signal level Table 9: Characteristics of the remote control Characteristics Conditions Uo Voltage selector switch Z set at 2.23 V/cell or without selector switch Ui nom 0.5 * Io nom Output voltage at: U cr fail 2.5...5.5 V U cr control 5.5...11.5 V U cr clamp 11.5...14 V U cr fail 14...60 V Rcr Input impedance f cr Frequency limit LT/UT 1240 typ LT 1840 typ 25.25 37.85 50.5 22.5 + U cr * 0.5 33.75 + U cr * 0.75 45 + U cr 28.25 42.37 56.5 25.25 37.85 50.5 1 The Power Partners. V 1 1 Unit M 1 Hz The inhibit input of the T xx40-7Z is not TTL/CMOS compatible and should be triggered by a switch, a relay or an open collector transistor. If the voltage selector switch Z is not set at 2.23 V per cell, the Ucr fail voltage rises accordingly. MELCHER 1 1 Note: An open inhibit/Ucr remote control input leads to a sensor error signal which is indicated by the Error LED at the front and high impedance of the "System good" signal. The output voltage is reduced to Ucr fail condition. LT/UT 1740 typ Edition 4/4.99 13/33 T Series AC-DC Converters >100 Watt Remote control by a resistive potential divider Remote control by an external voltage source. With a resistive potential divider or a potentiometer connected to the remote control input, a fixed output voltage can be programmed: Vo+ i/Ucr 1 M Vo- Uo+ 12 Rugged Environment i/Ucr 05062 28 + Ucr 05063 Vo- 22 - Ext. voltage source 5.5...11.5 V R1 28 Ucr R 22 R2 = 1 M * R/(1 M + R) Uo- Fig. 23 Voltage setting by an external voltage source Remote control by a temperature sensor 05064 Fig. 22 Voltage setting by a resistive potential divider Ucr = Uo - 45 V Ucr = (Uo - 33.75 V) * 4/3 Ucr = 2 * Uo - 45 V + The Power Partners. Sensor Temperature sensor cable (LT/UT 1740) (LT 1840) i/Ucr (LT/UT 1240) Vo+ Uo * R2 Ucr = -------- (R1 + R2) R2: Value with 1 M internal resistance in parallel with R. It is mandatory that: (R1 * R2) ------- >35 k (R1 + R2) otherwise the unit might not be able to start. MELCHER - Sensor wires Vo- 28 12 22 + - Battery Fig. 24 Voltage setting by a temperature sensor, wiring diagram The Melcher temperature sensor provides a temperature compensated charging process for lead acid batteries, see also: Temperature Sensors. Edition 4/4.99 14/33 Rugged Environment AC-DC Converters >100 Watt T Series Temperature Sensors The active T temperature sensors are of robust construction, mounted into a sealed aluminium tube of 12 mm outer diameter and 50 mm length. The sensors are water proof (IP 66) and high voltage tested with 1.4 kV DC. Connection should be done via the colored 3-wire cable to the T unit output (Vo+ and Vo-) and the remote control input Ucr. Wrong connection may damage the sensor. The temperature sensor should be as close to the battery terminal as possible for most accurate temperature measurements. 12/14 Vo+ brown 28 i/Ucr white 20/22 Vo- green 05065 Sensor Fig. 25 Wiring diagram sensor Table 10: Type survey Sensor types 1 2 Battery voltage nominal [V] Float charge voltage (20C) [V] Cell voltage (20C) [V/cell] Temp. coefficient [mV/K/cell] Cable length [m] S24-2.23-30-02 1 24 26.76 2.23 -3.0 2 S24-2.23-35-02 1 24 26.76 2.23 -3.5 2 S36-2.23-30-02 1 36 40.14 2.23 -3.0 2 S36-2.23-35-02 1 36 40.14 2.23 -3.5 2 S48-2.23-30-02 1 48 53.52 2.23 -3.0 2 S48-2.23-35-02 1 48 53.52 2.23 -3.5 2 S48-2.27-30-02 2 48 54.48 2.27 -3.0 2 S48-2.27-35-02 2 48 54.48 2.27 -3.5 2 Standard types for conventional tubular lead acid batteries. The same sensor can be used for battery systems with different cell voltages within the selectable range of Z. Each step on the selector switch changes the cell voltage by 10 mV in the range from 2.23 V up to 2.32 V, at 20C. Standard types for sealed lead acid batteries for LT 1740 without option Z. Battery specific sensors with cell voltages from 2.23 V up to 2.32 V and temperature coefficients from -2 up to -4.5 mV/ K/cell or different cable lengths are available upon request. Important remarks Note 1: By choosing a battery with a large temperature coefficient or with a high cell voltage, the required temperature range may be limited by the output voltage control range of the T unit(s). Note 2: The temperature sensor together with the mounting fixture should be mounted as close as possible to the battery. Through their chemical activity batteries may be warmer than the ambient temperature. Battery banks heat up if they are mounted too close together thus blocking free air flow. Since battery life is halved with every 10 K temperature increase, it is recommended that the batteries be mounted at the bottom of the cabinet or in a separate, cool area. Note 3: The sensor supply wire Vo+ (brown) should be refered to the T unit output pin 12/14. If the sensor common (green) wire is connected to the power bus, resistive voltage drops or voltage drops across decoupling diodes in the Vo- supply line will be compensated by the sensor. Decoupling diodes or fuses in the Vo- supply line are not recommended as in case of a short circuit across the output of a T unit, status signalling of the system is affected. Note 4: For installation of batteries see also VDE 510 as well as the recommendations of the battery manufacturers. Table 11: Sensor data Characteristics Condition min Tsensor Sensor temperature range Ucr = 5.5...11.5 V Ucr Control voltage range Absolute ratings Ucr td Control voltage tolerance Tsensor = 20C Tsensor = 0...53C MELCHER The Power Partners. Edition 4/4.99 15/33 typ max Unit -10 60 C 3.9 15 V 0.1 0.2 T Series AC-DC Converters >100 Watt Rugged Environment Functional Features Available Signals and Status Monitoring The T series feature an inhibit function as well as several voltage monitoring and indicating functions for easy control and surveillance of a complete custom specific power supply system. All the surveillance functions are driven from the T output potential and also operate in case of a mains failure down to an output voltage of 5 V. The power consumption of the surveillance circuit is typically 10 mA to 20 mA. With option D the output voltage can be sensed externally for example to monitor the system bus decoupled from the power supplies by diodes or fuses. With option D a resistor of 43.2 k 1% (21.5 k for T 1840) should be fitted externally into the sense line to the bus (see fig.: With option D; Power down signal monitoring...). 06050 - + Vo+ 12 Available functions: - Power Down D pin 30 D set pin 32 - System Good Sys In pin 24 Sys Out pin 26 - Inhibit/Ucr remote control i/Ucr pin 28 (see Chapters: Rectifier respectively: Battery Charger) Optical status monitoring is indicated by 3 LEDs on the front panel: - System (OK) green (OK) green - Uo - Error red Vo- 22 43.2 k (21.5 k) R T 1000-7 Fig. 26 Standard version; Power down signal monitoring directly the output of the T unit. 06051 - Test sockets at the front panel allow easy measurement of the output voltage. Vo+ 12 Power Down As it is driven from the output, power down operates independently of the input voltage and load conditions, even if the unit is inhibited. The standard version monitors the output voltage internally (see fig.: Standard version; Power down signal monitoring directly the output of the T unit). Rext D set 32 T 1000-7D External adjustment of R 43k2 the threshold level Ut (21k5) Fig. 27 With Option D; Power down signal monitoring the power bus decoupled by a fuse. Lower threshold level With the resistor (R ext) connected to D set input pin 32 and Vo- (or Vo+) the low threshold level can be increased (or decreased) respectively. (See fig. above) If the D set input is left open the low threshold level of the power down signal is factory set to: T 12xx: U t set = 21.0 V 0.4 V T 17xx: U t set = 42.5 V 0.5 V T 18xx: U t set = 32.0 V 0.4 V The approximate resistor values for given threshold levels can be calculated from the following formulae; (U t in V): Table 12: Calculation of Rext Types U t > U t set (R ext. connected to Vo-) U t < U t set (R ext. connected to Vo+) T 12xx 463.5 Rext (Ut) = -------- [k] Ut -21.0 43.2 Ut - 463.5 Rext (Ut) = ------------- [k] 21.0 - Ut T 17xx 933 Rext (Ut) = -------- [k] Ut - 42.5 43.2 Ut - 933 Rext (Ut) = ------------- [k] 42.5 - Ut T 18xx 461 Rext (Ut) = -------- [k] Ut - 32.0 21.4 Ut - 461 Rext (Ut) = ------------- [k] 32.0 - Ut The Power Partners. + F Vo- 22 The power down circuitry monitors the output voltage and changes its output signal status from low to high impedance when the output voltage falls below the low threshold level and changes back to low impedance, when the output voltage exceeds the upper threshold level. The rectifier versions have a relatively small hysteresis of 1 V, the battery charger versions have a large hysteresis. The upper threshold level is given the low threshold level is externally adjustable at the D set pin 32. Power Down can for example be used as a save data signal, for low voltage warning, as a low battery signal to avoid deep discharge of the battery during long term mains failure or to prevent connected converters from starting-up at a low bus voltage. For application examples see figures below for power down use. MELCHER External adjustment of the threshold level Ut Rext D set 32 Edition 4/4.99 16/33 Rugged Environment AC-DC Converters >100 Watt The threshold level is adjusted to a DC output voltage. When in operation a sinusoidal low frequency output ripple is superimposed on the DC output voltage. It can be estimated with Uov = I o/(2 * * f * C o) where C o is the internal capacitance of the output of the unit. Table 13: Resistor values (Rext) for given Power Down threshold value U t for LT 1740 (typical values) Characteristics Conditions Ut 69 k to Vo+ 106 k to Vo+ 254 k to Vo+ left open 309 k to Vo- 154 k to Vo- 102 k to Vo- Power Down threshold level set by Rext Ut Unit 34.4 36.4 39.5 42.5 45.5 48.5 51.6 V T Series Power down output signal characteristics The power down output D is an open collector transistor referenced to Vo-, protected by a 62 V Zener diode, and is well suited to driving an external relay. Under normal operating conditions (Uo > Ut) the power down output D has low impedance. If the output voltage drops below the power down threshold level, the signal output becomes high impedance. Table 14: Characteristics of Power Down functions Characteristics Conditions min typ max Unit ID TC min...TC max 50 1 mA I D = 50 mA 0.2 V 500 mW Output sink current Usat U saturation Upper threshold level The upper threshold level of the Power down function is given. 1 Uz Zener voltage Pz Z-diode PLOSS To be limited to 50 mA by the external circuitry. 06053 The rectifier units T xx01/02 have a relatively small hysteresis of 1 V to prevent oscillation of the signal. Vo+ 12 D 30 The battery charger units T xx40 have a large hysteresis. The upper level is set at 2.05 V/cell. To avoid deep discharge of the battery which would decrease the life expectancy, its load should be disconnected from the battery at the low level of the Power down signal. The battery voltage will then recover slowly up to its chemical equilibrium, about 2 V/cell. The load may not be connected again to the battery until the T unit is operating and charging it. Then the output voltage will be higher than 2.05 V/cell High level of Power down signal T 1240: 24.6 V 0.3 V T 1740: 49.2 V 0.5 V T 1840: 36.9 V 0.4 V 62 TC = 95 C Vo- T 1000 D set 32 22 Rext Fig. 29 Power Down - External adjustment of threshold level U t - Signal electrically isolated by an external relay 06054 Vo+ 12 U Bat U float R D 06052 Battery recovery 2.05 V/cell 2.0 V/cell red LED Load switch ON Vo- 22 Battery low Mains failure Z high low LED is "ON" in case of power down T 1000 Hysteresis Power Down Ut 30 Fig. 30 Remote indication of Power Down by LED Load switch OFF t 06055 Return of mains Vo+ 12 +5 V Power down signal R t D 30 Fig. 28 Hysteresis of power down signal for battery charger types with corresponding level of power down signal CMOS, TTL Vo- 22 T 1000 Fig. 31 Remote indication of the output voltage status by CMOS/ TTL interface for e.g. Save Data MELCHER The Power Partners. Edition 4/4.99 17/33 T Series AC-DC Converters >100 Watt Vi+ connecting the output of the system good signal of one unit to the input of the next unit. Low voltage (impedance) of the input and output has the meaning of "System good". The first input of the system has to be connected to Vo-. i The signal "System good" is activated (low impedance) if the following conditions are met: Gi- No external fault - The Sys input signal is logic low 06056 Vo+ 12 D 10 k 0.5 W 30 Vo- 22 Rugged Environment PSK/PSR T 1000 AND Fig. 32 Power Down used as inhibit to enable a system start-up in case of subsequently connected step-down converters PSK/PSR with low start-up voltage. (For CQ units no pullup resistor is required.) System Good The system good signal provides information about the general function of the T 1000. It can be used to monitor the status of a single T unit or can be linked with other signals within a power system to drive one single logic signal for the status of the whole system by No faults monitored by the T unit such as: - Input overvoltage - Input undervoltage (mains failure) - Output overvoltage - Output short circuit - Internal overtemperature - Internal circuit fault - Inhibit/Ucr remote control input error such as (inhibit) voltage < 2.5 V (rectifier type); control voltage out of range 5.3 V > U cr > 14 V (battery charger type) or sensor not connected, open remote control input. Table 15: Characteristics of the system good input and output Characteristics I Trig U Trig I Trig U Trig 1 Conditions Trigger level for logic low input (= System OK) Trigger level for logic high input (= System Failure) U i min...U i max TC min...TC max current driven voltage driven min typ - 0.4 current driven 0 voltage driven >7.5 Output sink U sat Saturation voltage UZ Zener voltage protection diode PZ Power disipation Zener diode I Sys Out = 50 mA Unit A 6.2 current 1 I sys max 100 V A 60 V 50 mA 0.2 V 500 mW 62 TC = 95C To be limited to 50 mA by the external circuitry. Signal input: Signal output: The system good input (Sys In) can be voltage or current driven. To trigger the internal comparator, the voltage at the Sys In pin has to be <6.2 V if voltage driven. If current driven, the sink current to Vo- has to be >100 A. An easy way to drive the system good input is achieved by means of an open collector transistor, or a 10 V CMOS interface. (See figures below) The system good signal output (Sys Out) is an open collector transistor referenced to Vo-, protected by a 62 V zener diode. The output is well suited for relay applications. 06060 Vo+ 12 Sys Out Note: If only the internal status of a T unit is to be monitored, Sys In has to be connected to Vo-. 26 06057 Logic high if no internal T unit error and no inhibit Logic AND Sys In 24 Ref. ISys In Vo- Vo+ 12 ISys Out Sys Out 26 T 1000 Fig. 34 System status signal electrically isolated by an external relay + - Logic high if ISys In > 100 A Fig. 33 Equivalent circuit of system good input and output MELCHER The Power Partners. No external freewheeling diode across 22 relay necessary Vo- 22 Edition 4/4.99 18/33 Rugged Environment AC-DC Converters >100 Watt T Series Connection in Series of Power Down and System Good (Examples) Paralleling of Power Down and System Good (Example) To achieve a logic OR function of the system good and power down signal connect the D output to Sys In. The desired function is then obtained from the system good output. The output signal becomes high if the output voltage is lower than the threshold of the power down circuit, inhibit is applied or an internal error has occurred. To achieve a logic AND function of the System Good and Power Down connect the D output with the system good output. This combination generates an output signal only in case of severe system errors. Only a T system fault together with a simultaneous Power Down of the output voltage will cause this output signal to become high impedance. 06062 06061 Vo+ 20/22 Vo- T 1000 24 Sys In Vo+ 20/22 Vo- T 1000 R 24 Sys In R 26 Sys Out 26 Sys Out Internal signals 28 Inhibit Internal signals 28 Inhibit Vo+ 30 D Vo+ 30 D 32 D set 32 D set Fig. 35 System Good and Power Down connected in series. Note: Output signal will indicate error at start-up. Fig. 37 System Good and Power Down connected in parallel. 1k CQ1 Output Control Circuit 20 V 06059 Sys In 24 1k CQ2 Output Control Circuit 20 V Vo+ 12 Sys Out 26 Vo- 22 Vo- 22 T 1000 1k CQn Output Control Circuit 20 V Fig. 36 Wired AND of electrically isolated open collector signals (e.g. the OUT OK signal of CQ units) with the system good signals of T units in series to achieve one signal about the status of the whole system MELCHER The Power Partners. Edition 4/4.99 19/33 Sys In 24 Vo+ 12 Sys Out 26 Vo- 22 Vo- T 1000 Overall System Good T Series AC-DC Converters >100 Watt Rugged Environment Display Status of LEDs LED Sys OK (green) corresponds to the system good signal. The LED is ON if no internal or external error is detected. LED Uo OK (green) indicates the output voltage status. It corresponds to the power down signal. The LED is ON as long as Uo has exceeded the upper threshold level and has not fallen below the low threshold level Ut. LED Error (red) is ON if one or more of the following conditions is detected: - Input overvoltage - Input undervoltage (mains failure) - Output overvoltage - Output short circuit - Output voltage below threshold U t - Internal overtemperature - Internal circuit fault - Inhibit/Ucr remote control input error such as: - (inhibit) voltage <2.5 V rectifier type - Remote control voltage out of range (5.3 V > Ucr > 14 V) battery charger type - Sensor not connected, open remote control input Table 16: System monitoring Signal status and LED display status depending on the situation of the various system elements Possible Situation Open collector output Power Down Sys OK Uo OK Error low low on on off high low off on on All OK No mains and battery OK or no mains and Uo > U t 2 Unit inhibited and battery OK or unit inhibited and Uo > Ut 2 Internal error 2 System good input logic high 3 high low off on off No mains and battery low or no mains and Uo < Ut 2 high high off off on 1 high high off off off low high on off on high low off on on Short circuit on LT output, Uo < 4 V Current limit LT output, Uo > 4 V, Uo < Ut 2 Battery charger type T xx40: sensor not connected or out of range 1 2 3 LED System Good LED is on until the output capacitors are discharged. Sys In connected to Vo-. Sys In not connected to Vo- (single T status monitoring) or system status monitoring (see: System Integration). MELCHER The Power Partners. Edition 4/4.99 20/33 Rugged Environment AC-DC Converters >100 Watt T Series Auxilliary Functions Connection in Parallel and in Series Connection in parallel: Current sharing between paralleled units is ensured by the output characteristic slope. Several T units may be connected in parallel. Fig. 38 Sensors connected in parallel. Sensors in parallel provide redundant voltage adjustment in case of one of the sensors in open circuit or short circuit (add. external components required) To enable hot plug-in in systems decoupled with fuses the T series is fitted with an NTC resistor limiting the reverse current flowing into the discharged output capacitors (see: Functional Description). For this purpose the pins 16 and 18 have to be connected to Vo+ and Vo- respectively (see fig.: T xx40 with battery back-up). Since pins 16 and 18 are leading pins, the output capacitors are precharged through the internal NTC resistor prior to any other pin making contact. This protects the connector and prevents the DC bus voltage from dropping during hot plug-in. Hot plugging should be done gently. Subsequent hot plug-out/plug-in of a unit with a hot NTC should be avoided as current limiting will be poor. After disconnecting an operating unit it should be cooled down prior to reconnecting to the bus to avoid damage of the fuse or the converter. T 1000 D set Vo- D set 06077 T 1000 T xx40 T xx40 The remote control input of the T xx40 units allows hot plugin to an operating battery system with a single sensor without affecting the float charge voltage. 06079 Note: The internal NTC limits the reverse charge current flowing into the output capacitors of a T unit when it is plugged into a battery buffered bus. Should however the T unit already be connected when the battery is switched to the bus, the resulting charge current will not be limited. To avoid the fuse to blow or a possible arc across the circuit breaker, the T units should be switched on to the mains prior to connecting the battery. With decoupling diodes, no reverse charge current flows from the power bus into the T output capacitors. R 43k2 HC+ Several T xx40 battery charger units connected in parallel can be controlled by a single voltage source or a single sensor wired to the remote control inputs. If sensors are connected in parallel (redundant configuration), they should be decoupled by 200 k resistors, (see fig.: Sensors connected in parallel). An individual sensor for each paralleled T unit is not recommended because current sharing is affected by the sensor tolerance. 22 Vo+ For battery applications decoupling of the T units with fuses is recommended since the voltage drop over the decoupling diodes would decrease the float charge voltage of the battery. In case of an internal short circuit at the output of a charger unit the battery will deliver a very large current causing the respective fuse to blow. The fuse should be mounted in the positive power path of the converter since the monitoring signals of the T units are referenced to the negative path. The fuse type should be suitable for DC application having a current rating of 20 A or more with high breaking capability, e.g. Littlefuse, series 314. Vo- HC- Decoupling diodes provide reverse polarity protection with no reverse current in case of hot plug-in, but have the disadvantage of the forward voltage drop over the diode and higher power loss. i/Ucr 28 Vo- Decoupling may either be done using series diodes or using appropriate fuses in the output path of each T unit. If the battery voltage is to be monitored, choose T units with option D. 200 k Vo+ For redundant configurations the outputs should be decoupled to protect the DC-bus in case of an internal short circuit at the output of any of the paralleled T units. Sensor Sensor 200 k HC- Power Boosting, Redundant Configuration, Hot Plug-in T xx40 HC+ Connection in series: A maximum of 2 T units may be connected in series, however the resulting output voltage of up to 110 V would no longer be SELV. For safety reasons the installation at the output should be protected with supplementary insulation (IEC/EN 60950). 06078 12 Vo+ The output of the T units may either be connected in series or in parallel. R Fuse Vo+ Vo- Vo+ Vo- (21k5) + 43k2 (21k5) Fuse + - - + Fig. 40 T xx40 with battery back-up. Power Down signal monitoring the battery voltage. - Fig. 39 T unit without battery back-up in redundant configuration MELCHER The Power Partners. Edition 4/4.99 21/33 T Series AC-DC Converters >100 Watt Rugged Environment Battery Size and Ripple Current Combination of T Units and CQ Units without Battery Some consideration should be given to the selection of the battery size. According to VDE 0510 part 2, the low frequency ripple current of the floating charge current should not exceed 5 Arms per 100 Ah capacity (0.05 C). The power factor corrected single step conversion of the line input voltage to the low DC output voltage generates a ripple voltage at the output of twice the input frequency, causing a ripple current into the connected battery. In a complete power system consisting of two or more T units in parallel combined with Melcher CQ units it may be desirable to have one common signal indicating the status of the whole system. For systems where only a small battery back-up time is required, battery charging by one T unit may be sufficient (see also fig. below). For systems with more than one T unit charging the battery please refer to the chapter: Back Plane. If in a system with 2 redundant T units Power Down is desired as one common signal, independent of a possible failure of one of the two T units, simply interconnect the D pins of the two T units. In this way Power Down only becomes active if both T units fail which would result in the bus voltage falling (see fig. below). 06081 T 1000 Load T 1000 Note: Consider the behaviour of the signalling in a system with decoupling diodes or fuses in the case of a T-failure, with the secondary in short circuit. Uo: 56.0 V + - + - 06082 Battery P N Fig. 41 Alternative configuration for a larger system with a small battery If the ripple current is too high e.g. in the case of a smaller battery to be connected to the system, a large capacitor with low impedance can be connected in parallel with the battery. Another possibility is to connect an additional impedance to the battery line, e.g. a choke or an NTC-resistor (30 A or 60 A chokes are available on request. Please consult Melcher's application center). Further considerations for the selection of battery size include desired back-up time, required battery life, temperature range and maximum permissible discharge current. Consult the manufacturers of lead-acid batteries for the final selection. Caution: Lead-acid batteries can generate certain amounts of H2 and O2 gas which can form explosive gas mixtures. Sufficient ventilation must be provided in battery cabinets and installation rooms. The Power Partners. CQ 1 + + - Out OK- Out OK+ - Vo+ Vo- R Sys Out P N Sys In D R Sys Out D P N Overall System Good Power Down + CQ 2 + - Out OK- Out OK+ - + CQ 3 + - Out OK- Out OK+ - Vo+ Vo- Sys In + - Fig. 42 Monitoring of overall System Good and Power Bus Down in a redundant system Local regulations must be observed. Further information about designing battery systems is contained in VDE 0510, part 2. MELCHER T 1701 T 1700-7D Uo range 50.5...56.0 V T 1701 Uo: 56.0 V The Melcher CQ units provide a galvanically isolated signal Out OK. To obtain a logic AND all CQ Out OK signals should be connected in series (see also fig.: Wired AND of galvanically isolated open collector signals). Out OK- of the first CQ unit should be connected to Vo-, Out OK+ of the last CQ unit should be connected to pin Sys In of one of the T units. Sys Out should be connected to Sys In of the next T unit. If one of the units fails (T or CQ ) it will be indicated by the overall System Good (see fig. below). Edition 4/4.99 22/33 Rugged Environment AC-DC Converters >100 Watt T Series Low Battery Discharge Protection Storing the System Good Signal Since all monitoring functions are powered by the output of the T unit or the battery in the case of a mains failure, Power Down can be used to monitor the status of the battery and to disconnect the load or part of it via the inhibit of the CQ units when the battery voltage drops below the threshold level of the Power Down. This prevents further discharge of the battery. See also: Power Down. For battery back-up systems located in inaccessible areas it could be of interest to know, whether there has been a Power Fail (interruption of the mains). To obtain this information Sys Out should be connected to Sys In with a reset button connected to Vo-. In this way a system failure like an interruption of the mains will be stored at Sys Out until the reset button is pressed. + - + - + - CQ 06083 + 06084 Fuse Out OK+ i - HC- + + Vo- - P P P N N T 1740-7DZ HC+ CQ N P N Out OK- i + - - Vo+ R Sys Out Out OK+ D HC+ HC- Vo- T 1740-7DZ Fuse Vo+ + Vo+ Out OK- CQ + Stored Sys Out - Vo+ - Sys In R + - Sys Out + CQ Temp. sensor Reset Out OK- Sys In Out OK+ i D set Fig. 44 Storing the System Good signal - 43.2 k R ext + - Temp. sensor Fig. 43 Disconnecting the loads at low battery voltage in case of mains failure +5.1 V, 64 A (48 A*) 06085 * For redundancy, decoupling at the CQ-outputs with diodes is required. CQ CQ NP 24 V, 8 A (4 A*) 12 V, 16 A (8 A*) CQ CQ CQ CQ CQ CQ Fuse T 1740-7DZ Fuse T 1740-7DZ + Back-up battery - 48 V Temp. sensor System Controller 48 Vnom Power Bus (SELV) (50.5...56.5 V DC) Power down DC bus good Output good Fig. 45 UPS uninteruptable power supply system MELCHER The Power Partners. Edition 4/4.99 23/33 T Series AC-DC Converters >100 Watt Rugged Environment 12 V, 4 A +24 V, 5 A 06086 +5.1 V, 32 A CQ 1001-6R CQ 1001-6R P T 1701 CQ 2320-7R PSB 245-7R Vo+ N Vo- System Controller 48 V DC nom Power Bus (SELV) (53...56 V DC) Power Down DC bus good Output good M Cooling fan Fig. 46 Front end with various loads (example) MELCHER The Power Partners. Edition 4/4.99 24/33 Lamps PCB heating Rugged Environment AC-DC Converters >100 Watt T Series Electromagnetic Compatibility (EMC) A suppressor diode or a metal oxide VDR (depending upon the type) together with an input fuse and an input filter form an effective protection against high input transient voltages which typically occur in most installations, but especially in battery driven mobile applications. The T series has been successfully tested to the following specifications: Electromagnetic Immunity Table 17: Immunity type tests Phenomenon Standard 4 Level Coupling mode 2 Value applied Waveform Source imped. Test procedure Electrostatic discharge (to case) IEC/EN 61000-4-2 4 contact discharge 8000 Vp 1/50 ns 330 yes 1 air discharge 15000 Vp 10 positive and 10 negative discharges Electromagnetic IEC/EN field 61000-4-3 3 antenna 10 V/m AM 80% 1 kHz n.a. 26...1000 MHz yes 1 Electrical fast transient/burst IEC/EN 61000-4-4 4 capacitive, o/c 2000 Vp 50 1 direct, i/c, +i/-i 4000 Vp 1 min positive 1 min negative transient per coupling mode yes 4 bursts of 5/50 ns 2.5/5 kHz over 15 ms; burst period: 300 ms Surge IEC/EN 61000-4-5 3 i/c 2000 Vp 1.2/50 s 12 yes 1 4 +i/-i 5 pos. and 5 neg. surges per coupling mode VDE 0160 II +i/-i 2.3 * Uip 0.1/1.3 ms 1700 J max 3 pos. and 3 neg. impulses 6 repetition yes 3 IEC/EN 61000-4-6 3 i, o, signal wires 10 Vrms (140 dBV) AM 80% 1 kHz 150 0.15...80 MHz yes 1 Conducted disturbances 2 In Peroper. form. 1 Normal operation, no deviation from specifications i = input, o = output, c = case. 3 Normal operation, short deviation from specs. possible 4 Related and previous standards are referenced in: Technical Information: Standards 2 Electromagnetic Emission The conducted noise emitted at the input of the T units within the frequency range of 10 kHz to 30 MHz is below level B according to CISPR 11/22/EN 55011/22 under all operating conditions. The radiated noise in the frequency range of 30 MHz to 300 MHz on the input- and the output-side of the T units stays below the limit of CISPR 14/EN 55014 measured [dBV] 90 with an MDS-clamp and below level A, according to CISPR 11/22/EN 55011/22 measured with an antenna. The radiated noise of the T units between 30 MHz and 1 GHz will be reduced if the unit is built into a conductive chromatized 19" rack, fitted with a Melcher front panel. For units mounted otherwise, e.g. for wall mounting with option B1 (base plate) the radiated noise may be above level A. [dBV/m] 50 07035 07039 A 80 A 40 70 B B 60 30 50 40 20 30 20 10 10 Fig. 47 Typical disturbance voltage (quasi-peak) at the input of a T series AC-DC converter according to CISPR 11/22 and EN 55011/22, measured at Ui nom and Io nom. MELCHER The Power Partners. 500 200 100 50 1000 [MHz] 0 30 20 30 10 5 2 1 0.5 0.1 0.05 MHz 0.02 0.01 0 Fig. 48 Typical radiated electromagnetic field strength (quasi peak) of an LT 1740 according to CISPR 11/22/EN 55011/22, normalized to a distance of 10 m, measured on an open area test site at Ui nom and Io nom. Edition 4/4.99 25/33 T Series AC-DC Converters >100 Watt Rugged Environment Immunity to Environmental Conditions Table 18: Mechanical stress Test method Ca Standard Test conditions Status Temperature: Relative humidity: Duration: 40 2 C IEC/EN/DIN EN 60068-2-27 Acceleration amplitude: Bump duration: Number of bumps: 100 gn = 981 m/s2 6 ms 18 (3 each direction) Unit operating Bump (half-sinusoidal) IEC/EN/DIN EN 60068-2-29 Acceleration amplitude: Bump duration: Number of bumps: 40 gn = 392 m/s2 6 ms 6000 (1000 each direction) Unit operating Vibration (sinusoidal) IEC/EN/DIN EN 60068-2-6 Acceleration amplitude: 0.21 mm (10...60 Hz) Unit 3 gn = 29.4 m/s2 (60...2000 Hz) operating 10...2000 Hz 7.5 h (2.5 h each axis) Damp heat steady state IEC/DIN IEC 60068-2-3 Ea Shock (half-sinusoidal) Eb Fc Unit not operating 93 +2/-3 % 56 days Frequency (1 Oct/min): Test duration: Fda Random vibration wide band Reproducibility high IEC 60068-2-35 DIN 40046 part 23 Acceleration spectral density: 0.05 gn rms Frequency band: 20...500 Hz Acceleration magnitude: 4.9 gn rms Test duration: 3 h (1 h each axis) Unit operating Kb Salt mist, cyclic (sodium chloride NaCl solution) IEC/EN/DIN IEC 60068-2-52 Concentration: Duration: Storage: Storage duration: Number of cycles: Unit not operating 5% (30C) 2 h per cycle 40C, 93% rel. humidity 22 h per cycle 3 Table 19: Temperature specifications Temperature -7 Characteristic Conditions min TA Io = 0...Io nom Io > Io nom Ambient operational temperature range Case operational temperature range at measurement point (see: Mechanical Data) TS Storage temperature range (not operating) TCs Shut down case temperature Unit -25 71 C -25 65 Io = 0...Io nom -25 95 Io > Io nom -25 90 -40 100 100 R th CA Thermal resistance case to ambient C max limited by Ucr range Temperature range for battery charging TC typ convection cooling Thermal time constant of case 0.5 K/W 1 h Table 20: MTBF Values at specified case temperature MTBF 1 Device 1 2 Module types LT 1701-7 Ground benign 40C 198'000 hours 2 Ground fixed 40C 70C 56'000 26'000 Ground mobile 50C Unit 20'000 h 810'000 Calculated in accordance with MIL-HDBK-217E (calculation according to edition F would show even better results) Statistical values, based on an average of 4300 working hours per year and in general field use, over 3 years MELCHER The Power Partners. Edition 4/4.99 26/33 Rugged Environment AC-DC Converters >100 Watt T Series Environmental Conditions Thermal Considerations Despite the fact that the T series have a very high efficiency the operating losses of the unit will heat the case. The heat sinks are designed to dissipate the power losses at maximum output power over the specified temperature range without forced cooling if the convection cooling provides sufficient air volume, without obstructions for vertical air exchange below and above the units. Because of the slightly higher power losses in output power and current limitation mode the maximum admissible ambient and case temperature is then lower than in output voltage regulation mode. The T series have a built-in overtemperature shut down to protect the internal circuitry. Derating is required for applications with higher operational ambient temperature. Fig.: Output power vs. ambient temperature shows the derating of the output power versus operational temperature above the specified ambient temperature of 71C of an LT 17xx unit. Two different conditions are shown: a) Unit operating with convection cooling (solid line). For example if the operational ambient temperature reaches 80C, the maximum output power should be limited to approx. 290 W. In this case steady operation in output power or current limitation mode is not possible. Po max (convection cooling) Po [W] 08002 550 Po max (forced cooling) Output voltage regulation mode (Io <10 A) b) Unit operating with forced cooling (dotted line). Under these conditions, the case temperature of the T unit is decisive. With sufficient cooling provided (air flow!), the unit still delivers 550 Watts output power in voltage regulation mode even at 85C ambient temperature, provided that the maximum case temperature of 95C is not exceeded (Measuring point of case tempertature TC, see: Mechanical Data). If the case temperature does not exceed 90C, steady operation in output power or current limitation mode is still possible. Nevertheless it is not recommended to operate the units continuously close to the maximum case temperature since life time will be reduced. Since the operating temperature of a power supply is of major importance to reliability the following conditions should be considered: 1. 2. 3. 4. Do not cover heat sinks. Do not obstruct air flow around the heat sinks. Maximize free space around the units. In a system where the power supplies as well as the loads are located in the same enclosure, forced cooling is recommended. The T units should be placed in the lower section of the enclosure. 5. In a closed system heat may build up causing excessive temperatures. 6. Always check the maximum ambient and case temperature after system integration. Ploss [W] 08003 45 Output power limitation 40 290 Output current limitation 35 30 Output power/current limitation mode (Io >10 A) 0 -25 25 Output voltage regulation TA [C] 50 60 70 80 90 95 100 Fig. 49 Output power versus ambient temperature of T 17xx 20 15 10 5 0 0 100 200 Ui = 110 Vrms 300 Po [W] 400 500 600 U i = 230 Vrms Fig. 50 Internal power losses versus nominal output power of T 17xx MELCHER The Power Partners. Edition 4/4.99 27/33 T Series AC-DC Converters >100 Watt Rugged Environment Mechanical Data Dimensions in mm. Tolerances 0.3 mm unless otherwise indicated. European Projection 1.5 09036 94.8 3U/111 System (ok) (green) Uo (ok) (green) Testsockets Error LED (red) 26.8 28 TE/141.5 171.93 (DIN 41494) 1 168.5 Case temperature measuring point 1 Measuring point 2 of case temperature Tc 60 30 94.8 3U/111 Fixtures for retention clips "V" for female connector Trim-potentiometer (T xx40) Cell voltage selector switch Z (T xx40) Input fuse (Option) 0.73 51/2 0.3 8 1 /2 TE TE 28 TE /142.2 Fig. 51 Case T01, weight 3.0 kg MELCHER The Power Partners. Edition 4/4.99 28/33 Measuring point 1 of case temperature Tc Rugged Environment AC-DC Converters >100 Watt T Series 12.35 158 5 101 111 09037 5 12 o 4.5 M4 17.3 133.4 5 168.5 119 171.93 (DIN 41494) Measuring point of case temperature Tc 28.3 Front panel Fig. 52 Case T01 with option B1 (cooling plate) 15 12 14.5 25 0.2 09044 l 60 adhesive tape l: 2 m standard length other cable lengths on request Fig. 53 Temperature sensor with mounting fixture. MELCHER The Power Partners. Edition 4/4.99 29/33 8 T Series AC-DC Converters >100 Watt Rugged Environment Safety and Installation Instructions Table 21: H15 Connector pin allocation Connector Pin Allocation The connector pin allocation table defines the electrical potentials and the physical pin positions on the H15 connector. Pin no. 8 and pin no. 10, the protective earth pins present on all T series AC-DC converters are leading, ensuring that they make contact with the female connector first. 10079 Pin 6 10 14 18 22 26 30 4 Electrical determination 4 Phase 6 Neutral Designation P~ N~ earth 1 8 Protective 10 Protective earth 1 12 Output voltage positive Vo+ 14 Output voltage positive Vo+ contact 1 3 positive HC+ 16 Hot plug-in 12 18 Hot plug-in contact 1 3 negative HC- 16 20 Output voltage negative Vo- 20 22 Output voltage negative 24 24 System good signal input 28 26 System good signal output 28 Inhibit input 2 or Remote control input 8 32 Fig. 54 View of module's male H15 connector 30 Power down signal 32 Power down signal threshold of Uo VoSys In Sys Out i/Ucr D D set 1 Leading pin (pre-connecting). Unit operates with open inhibit. 3 External connections see: Auxiliary Functions: Power Boosting, Redundant Configuration, Hot Plug-in. 2 Installation Instruction The T series AC-DC converters are components, intended exclusively for inclusion within other equipment by an industrial assembly operation or by professional installers. Installation must strictly follow the national safety regulations in compliance with the enclosure, mounting, creepage, clearance, casualty, markings and segregation requirements of the end-use application. See also: Technical Information: Installation and Application. Connection to the system shall be made via the female connector H15 (see: Accessories) according to: Connector pin allocation. Other installation methods may not meet the safety requirements. Check for hazardous voltages before altering any connections. The AC-DC converters are provided with pins 8 and 10 ( ), which are reliably connected to the case. For safety reasons it is essential to connect at least one of these pins to the protective earth of the supply system. The P~ input (pin no. 4) is internally fused. This fuse is designed to protect the unit in case of overcurrent and may not be able to satisfy all customer requirements. External fuses in the wiring to one or both input pins (no. 4 and/or no. 6) may therefore be necessary to ensure compliance with local requirements. A second fuse in the wiring to the neutral terminal N~ is needed if: * Local requirements demand an individual fuse in each source line * Neutral to earth impedance is high or undefined * Phase and neutral of the mains are not defined or cannot be assigned to the corresponding terminals (L to phase and N to neutral). MELCHER The Power Partners. Important: Do not open the modules, or guarantee will be invalidated. Caution: Prior to handling, the AC-DC converter must be disconnected from mains and from other sources (e.g. batteries). Check for hazardous voltages and hazardous energy before and after altering any connections. Hazardous energy levels may be present at the output terminals for 3 minutes even after the mains input voltage has been disconnected from the unit. This is indicated by the red error LED. It is the responsibility of the installer to prevent an unwanted short-circuit of the ACDC converter and of the batteries. To prevent an unwanted short-circuit across the output of a disconnected unit, pins 16 and 18 are leading. In case of a short-circuit across the output of a T-unit, all LEDs will be off, though the mains may be present. Due to high output current value, the T series AC-DC converters provide for each the positive and the negative output path two internally parallel connected contacts (pins 12/ 14 and pins 20/22 respectively). It is recommended to connect the load to both female connector pins of each path in order to keep the voltage drop and power loss across the connector pins to an absolute minimum. If a T series AC-DC converter is used for battery charging, check wether the position of the cell voltage selector switch corresponds to the required battery cell voltage prior to putting a system into operation. Caution: Lead-acid batteries can generate H2 and O2 gas which can form explosive mixtures. Sufficient ventilation must be provided in battery cabinets and installation rooms. Edition 4/4.99 30/33 Rugged Environment AC-DC Converters >100 Watt Further information about designing battery systems is contained in VDE 0510, part 2. T Series the function of the unit nor is it detrimental to its performance over time. If a T unit is to be parallel connected with another T unit, it is recommended to connect the two hot plug-in pins of each female connector, HC+ (pin 16) and HC- (pin 18) to their respective output pins Vo+ and Vo- to provide the hot plugin capabilities. Standards and approvals All T series AC-DC converters correspond to class I equipment. They are UL recognized according to UL 1950, UL recognized for Canada to CAN/CSA C22.2 No. 950-95 and LGA approved to IEC/EN 60950 standards and have been evaluated in accordance with these standards for: * Building in * Basic insulation between input and case, based on 250 V AC * Double or reinforced insulation between input and output, based on 250 V AC * Operational insulation between output and case * The use in a pollution degree 2 environment * Connecting the input to a primary circuit with a maximum transient rating of 2500 V (overvoltage class III based on a 110 V primary circuit, overvoltage class II based on a 230 V primary circuit). In case of remote temperature control, the temperature sensor should be connected according to its wiring diagram. Wrong connection may damage the sensor. Make sure that there is sufficient air flow available for convection cooling. This should be verified by measuring the case temperature when the unit is installed and operated in the end-use application. The maximum specified case temperature TC max must not be exceeded. See also: Thermal Considerations. If the end-product is to be UL certified, the temperature test may be repeated asv part of the end-product investigation. Ensure that a unit failure (e.g. by an internal short-circuit) does not result in a hazardous condition. See also: Safety of operator accessible output circuit. The AC-DC converters are subject to manufacturing surveillance in accordance with the above mentioned UL, CSA, EN and with ISO 9001 standards. Cleaning Agents Isolation In order to avoid possible damage, any penetration of cleaning fluids is to be prevented, since the power supplies are not hermetically sealed. The electric strength test is performed as factory test in accordance with IEC/EN 60950 and UL 1950 and should not be repeated in the field. Melcher will not honour any guarantee claims resulting from electric strength field tests. Audible Noise Under certain operating conditions, a T series AC-DC converter may generate a slight audible noise due to magnetostriction in the transformer. This noise does neither affect Important: Testing by applying AC voltages will result in high and dangerous leakage currents flowing through the Y-capacitors (see fig.: Block diagram). Table 22: Isolation Characteristic Electric strength test voltage Sensor Unit Input to case Input to output Output to case Output to case 1.5 3.0 1 0.5 0.5 kVrms kV DC Required according to IEC/EN 60950 2.1 4.2 1 0.7 0.7 Actual factory test 1 s 2.8 5.6 1 1.4 1.4 AC test voltage equivalent to actual factory test 2.0 4.0 1 1.0 1.0 kVrms >300 >300 >300 >100 M Insulation resistance at 500 V DC In accordance with IEC/EN 60950 only subassemblies are tested in factory with this voltage. Leakage Currents in AC-DC operation Under test conditions, the leakage current flows through a measuring instrument (MI) as described in fig.: Measuring instrument for earth leakage current tests, which takes into account impedance and sensitivity of a person touching unearthed accessible parts. The current value is calculated by dividing the measured voltage by 500 . If inputs and/or outputs of T units are connected in parallel, their individual leakage currents are added. MELCHER The Power Partners. 1500 MI Leakage currents flow due to internal leakage capacitance and RFI suppression Y-capacitors. The current values are proportional to the mains voltage and nearly proportional to the mains frequency. They are specified at maximum operating input voltage where phase, neutral and protective earth are correctly connected as required for class I equipment. 10061 1 LT/UT AC-DC converter 500 10 k 220 nF 22 nF V Fig. 55 Measuring instrument (MI) for earth leakage current tests according to IEC/EN 60950, Annex D. Edition 4/4.99 31/33 T Series AC-DC Converters >100 Watt Rugged Environment 10070 P N 10071 Vo+ P N L1 L2 N T 1000 MI for earth leakage current S2 S3 L2 L2 Vo- S1 L1 Vo+ S3 Fig. 56 Test set-up for leakage current tests on class I equipment in single phase configuration. S1 is used to simulate the interchanging of phase and neutral, S2/3 select either the earth or output leakage current measurements, S4 selects either the positive or negative output leakage current measurements. N LT 1000 S2 MI for output leakage current P Vo- MI for earth leakage current MI for output leakage current Fig. 57 Test set-up for leakage current tests on class I equipment in 208 V phase to phase configuration. S2/3 select either the earth or output leakage current measurements, S4 selects either the positive or negative output leakage current measurements. Table 23: Leakage currents Characteristic Earth leakage current Output leakage current 1 T 1000 Unit Permissible according to IEC/EN 60950 3.5 mA Specified value at 255 V, 50 Hz (LT) 1.8 1 Specified value at 127 V, 60 Hz (LT or UT) 1.1 1 Permissible according to IEC/EN 60950 0.25 Specified value at 255 V, 50 Hz (LT) <0.1 Specified value at 127 V, 60 Hz (LT or UT) <0.1 In phase to phase configuration, leakage current is lower. Safety of operator accessible output circuit If the output circuit of an AC-DC converter is operator accessible, it shall be an SELV circuit according to IEC/EN 60950 related safety standards The following table shows a possible installation configuration, compliance with which causes the output circuit of the AC-DC converter to be an SELV circuit according to IEC/ EN 60950 up to a configured output voltage (sum of nominal voltages if in series or +/- configuration) of 56.5 V. However, it is the sole responsibility of the installer to assure the compliance with the relevant and applicable safety regulations. More information is given in: Technical Information: Safety. Protection Degree IP 30 if female connector is fitted to the unit. Table 24: Safety concept leading to an SELV circuit Conditions AC-DC converter Installation Result Supply voltage Grade of isolation between input and output, provided by the AC-DC converter Measures to achieve the resulting safety status of the output circuit Safety status of the AC-DC converter ouput circuit Mains 250 V AC Double or reinforced Installation according to the appliable standards SELV circuit P Mains P~ Fuse N 10021 Fuse + Vo+ AC-DC conN~ Vo- verter SELV - Earth connection Fig. 58 Schematic safety concept Use input fuses and earthing of the AC-DC converter as per: Installation Instructions. MELCHER The Power Partners. Edition 4/4.99 32/33 Rugged Environment AC-DC Converters >100 Watt T Series Description of Options D Remote Bus Voltage Monitoring F Externally Accessible Fuse This option is designed for systems using Melcher backplanes or is inteded for use in applications where a fuse or a decoupling diode is fitted into the positive supply line to the system bus. The status of the system bus/battery voltage can be monitored rather than the output status of a single T unit. To maintain the adjustment capabilities and resistor values for setting the different threshold values a 43.2 k (21.5 k) resistor should be fitted into the sense line to the bus. If the D set pin is left open the T unit signals permanently Low Bus Voltage. The standard T units have internally a 5 x 20 mm fuse which is externally not accessible. Some applications require an externally accessible fuse. Option F provides a fuse mounted on the back plate neer the converter. The full self-protecting functions of the module do normally not lead to broken fuses, except as a result of overvoltage at the input or if a power component inside fails (switching transistor, freewheeling diode, etc.). In such cases the defective unit has to be returned to Melcher for repair. (See also: Power Down as well as data sheet: Back Planes for the T Series) B1 Cooling Plate If a cooling surface is available the T 1000 units can be provided with a mounting plate (option B1) instead of the standard heat sink fitted to the right hand side of the unit. Since approximately 50% of the losses have to be dissipated through the heat sink on the left hand side sufficient free air flow has still to be provided. Accessories A variety of electrical and mechanical accessories are available, including: - Front panels for 19" rack mounting, Schroff system - Mating H15 connectors with screw, solder, fast-on or pressfit terminals - Connector retention facilities - Code key system for connector coding - 19" racks for system integration - Back planes for system integration - Temperature sensors for battery charging Back planes for system intergration For more detailed information refer to: Accessory Products. 19" Rack Front panels H15 female connector Code system MELCHER The Power Partners. Edition 4/4.99 33/33