Self-protecting resistor for capacitor
charging
PTC thermistors in plastic case
Series/Type: B5920*
Date: December 2006
EPCOS AG 2006. Reproduction, publication and dissemination of this publication, enclosures hereto and the
information contained therein without EPCOS' prior express consent is prohibited.
1) Vmax: Maximum permissible DC voltage directly applied to the PTC thermistor.
Applications
Inrush current limiter (charging resistor) for
smoothing and DC link capacitors
To replace high-power fixed resistors for
capacitor charging
Features
Self-protecting in case of malfunction of
short-circuit relay or internal short-circuit of
capacitor
Encased thermistor disk with clamp contacts
For high pulse currents and a high number of
operating cycles
Flame-retardant plastic case
Case material UL-listed
Sn-plated lead-free solder pins
Manufacturer's logo and type designation
stamped on in white
RoHS-compatible
Delivery mode
Packed in carton box
Dimensional drawing
Dimensions in mm
General technical data
Operating cycles at Vmax (charging of capacitor) Nc> 100000 cycles
Switching cycles at Vmax (failure mode) Nf> 10 cycles
Thermal cooling time constant (typical) τth 150 s
Heat capacity (typical) Cth 2.0 J/K
Operating temperature range (V = 0) Top 40/+125 °C
Operating temperature range (V = Vmax) Top 0/+85 °C
Electrical specifications and ordering codes
Vmax1)
VDC
RR
Ω
∆RR
%
Tref
°C
Ipulse,max
Ap
VBD
V
Ordering code
550 20 30 135 50 > 700 B59201J0140B010
650 56 30 135 25 > 700 B59202J0135B010
800 100 25 130 20 > 900 B59204J0130B010
Self-protecting resistor for capacitor charging
PTC thermistors in plastic case J201, J202, J204
Page 2 of 6Please read Cautions and warnings and
Important notes at the end of this document.
Note
In case the PTC is operated in the AC branch, a max. AC voltage of 440 VRMS can be directly
applied to the PTC thermistor without series current limiting resistor.
Calculation of the number of required PTC elements
Number of required PTC elements (connected in parallel) as function of capacitance and charging
voltage of smoothing or DC link capacitor:
N Number of required PTC thermistors connected in parallel
C Capacitance of smoothing or DC link capacitor in F
V Charging voltage of capacitor in V
Cth Heat capacity in J/K
Tref Reference temperature of PTC in °C
TA,max Expected maximum ambient temperature in °C
In case of large N values the resulting resistance of the parallel PTC network might be too low for
effective limitation of the charging current. In this case a combination of series and parallel
connected PTC thermistors can be used.
Self-protecting resistor for capacitor charging
PTC thermistors in plastic case J201, J202, J204
Page 3 of 6Please read Cautions and warnings and
Important notes at the end of this document.
Cautions and warnings
General
EPCOS thermistors are designed for specific applications and should not be used for purposes
not identified in our specifications, application notes and data books unless otherwise agreed
with EPCOS during the design-in-phase.
Ensure suitability of thermistor through reliability testing during the design-in phase. The
thermistors should be evaluated taking into consideration worst-case conditions.
Storage
Store thermistors only in original packaging. Do not open the package before storage.
Storage conditions in original packaging: storage temperature 25 °C ... +45 °C, relative
humidity ≤75% annual mean, maximum 95%, dew precipitation is inadmissible.
Avoid contamination of thermistors surface during storage, handling and processing.
Avoid storage of thermistor in harmful environment with effect on function on long-term
operation (examples given under operation precautions).
Use thermistor within 6 months after delivery.
Handling
PTCs must not be dropped. Chip-offs must not be caused during handling of PTCs.
Components must not be touched with bare hands. Gloves are recommended.
Avoid contamination of thermistor surface during handling.
Soldering (where applicable)
Use rosin-type flux or non-activated flux.
Insufficient preheating may cause ceramic cracks.
Rapid cooling by dipping in solvent is not recommended.
Complete removal of flux is recommended.
Standard PTC heaters are not suitable for soldering.
Mounting
Electrode must not be scratched before/during/after the mounting process.
Contacts and housing used for assembly with thermistor have to be clean before mounting.
Especially grease or oil must be removed.
When PTC thermistors are encapsulated with sealing material, the precautions given in chapter
"Mounting instructions", "Sealing and potting" must be observed.
When the thermistor is mounted, there must not be any foreign body between the electrode of
the thermistor and the clamping contact.
The minimum force of the clamping contacts pressing against the PTC must be 10 N.
During operation, the thermistor’s surface temperature can be very high. Ensure that adjacent
components are placed at a sufficient distance from the thermistor to allow for proper cooling at
the thermistors.
Ensure that adjacent materials are designed for operation at temperatures comparable to the
surface temperature of thermistor. Be sure that surrounding parts and materials can withstand
this temperature.
Avoid contamination of thermistor surface during processing.
Self-protecting resistor for capacitor charging
PTC thermistors in plastic case J201, J202, J204
Page 4 of 6Please read Cautions and warnings and
Important notes at the end of this document.
Operation
Use thermistors only within the specified temperature operating range.
Use thermistors only within the specified voltage and current ranges.
Environmental conditions must not harm the thermistors. Use thermistors only in normal
atmospheric conditions. Avoid use in deoxidizing gases (chlorine gas, hydrogen sulfide gas,
ammonia gas, sulfuric acid gas etc), corrosive agents, humid or salty conditions.Contact with
any liquids and solvents should be prevented.
Be sure to provide an appropriate fail-safe function to prevent secondary product damage
caused by abnormal function (e.g. use VDR for limitation of overvoltage condition).
Self-protecting resistor for capacitor charging
PTC thermistors in plastic case J201, J202, J204
Page 5 of 6Please read Cautions and warnings and
Important notes at the end of this document.
The following applies to all products named in this publication:
1. Some parts of this publication contain statements about the suitability of our products for
certain areas of application. These statements are based on our knowledge of typical re-
quirements that are often placed on our products in the areas of application concerned. We
nevertheless expressly point out that such statements cannot be regarded as binding
statements about the suitability of our products for a particular customer application.
As a rule, EPCOS is either unfamiliar with individual customer applications or less familiar
with them than the customers themselves. For these reasons, it is always ultimately incum-
bent on the customer to check and decide whether an EPCOS product with the properties de-
scribed in the product specification is suitable for use in a particular customer application.
2. We also point out that in individual cases, a malfunction of passive electronic compon-
ents or failure before the end of their usual service life cannot be completely ruled out
in the current state of the art, even if they are operated as specified. In customer applica-
tions requiring a very high level of operational safety and especially in customer applications
in which the malfunction or failure of a passive electronic component could endanger human
life or health (e.g. in accident prevention or life-saving systems), it must therefore be ensured
by means of suitable design of the customer application or other action taken by the customer
(e.g. installation of protective circuitry or redundancy) that no injury or damage is sustained by
third parties in the event of malfunction or failure of a passive electronic component.
3. The warnings, cautions and product-specific notes must be observed.
4. In order to satisfy certain technical requirements, some of the products described in this
publication may contain substances subject to restrictions in certain jurisdictions (e.g.
because they are classed as “hazardous”). Useful information on this will be found in our
Material Data Sheets on the Internet (www.epcos.com/material). Should you have any more
detailed questions, please contact our sales offices.
5. We constantly strive to improve our products. Consequently, the products described in this
publication may change from time to time. The same is true of the corresponding product
specifications. Please check therefore to what extent product descriptions and specifications
contained in this publication are still applicable before or when you place an order. We also
reserve the right to discontinue production and delivery of products. Consequently, we
cannot guarantee that all products named in this publication will always be available.
6. Unless otherwise agreed in individual contracts, all orders are subject to the current ver-
sion of the “General Terms of Delivery for Products and Services in the Electrical In-
dustry” published by the German Electrical and Electronics Industry Association
(ZVEI).
7. The trade names EPCOS, EPCOS-JONES, Alu-X, Baoke, CeraDiode, CSSP, MLSC, Phase-
Cap, PhaseMod, SIFERRIT, SIFI, SIKOREL, SilverCap, SIMID, SIOV, SIP5D, SIP5K, Ultra-
Cap, WindCap are trademarks registered or pending in Europe and in other countries. Fur-
ther information will be found on the Internet at www.epcos.com/trademarks.
Important notes
Page 6 of 6
