The 8500 series Programmable DC Electronic
Loads can be used for testing and evaluating a
variety of DC power sources. Their wide
operating ranges of up to 500 V and 240 A,
flexible operating modes and excellent
measurement accuracy make the 8500 series
well suited for characterizing DC Power
supplies, DC-DC Converters, batteries, fuel
cells and solar cells.
The loads can operate in CC, CV, CR or CP
mode while voltage/current or resistance/power
values are measured and displayed in real time.
Load terminals are isolated and floating. Over
temperature, over power, over voltage, over
current and reverse polarity protection will help
protect your valuable prototype and circuits.
The DC loads are easy to use. All parameters
can be set quickly and precisely from the front
panel, or programmed via RS232 or USB
interfaces.
DC Electronic Loads
8500 Series
Versatile & Economical DC Electronic
Loads
Technical data subject to change
© B&K Precision Corp. 2014
Data Sheet
www.bk prec ision.c om
The 8500 family offers 10 models with a wi de range of ratings
When selecting a DC load, it is important to
consider not only voltage and current
requirements, but also power ratings. The power
used when testing must fall within the hatched
region for the appropriate DC load.
Some applications may require high voltage/low
current and low voltage/high current which a
single load may not be able to handle. B&K
Precision’s broad range of DC loads will allow
you to select the optimal model for your
requirements.
2400W 600 W - 1200 W 300 W
Input current
Rated power
Input volta ge
Model Power Operating Voltage Rated Current
8500 300 W 0.1 - 120 V 30 A
8502 300 W 0.1 - 500 V 15 A
8510 600 W 0.1 - 120 V 120 A
8512 600 W 0.1 - 500 V 30 A
8514 1200 W 0.1 - 120 V 240 A
8518 1200 W 0.1 - 60 V 240 A
8520 2400 W 0.1 - 120 V 240 A
8522 2400 W 0.1 - 500 V 120 A
8524 5000 W 0.1 - 60 V 240 A
8526 5000 W 0.1 - 500 V 120 A
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DC Electronic Loads
8500 Series
2
Features
■Constant current (CC), resistance (CR), voltage
(CV) and power (CP) operation
■Wide voltage and current range, 0 to 500 V, 0
to 240 A (5000 W max)
■Low minimum operating voltage of < 0.1 V
and minimum input resistance of 5 mΩ(model
8518) allowing the load to sink high current at
low voltages, required for fuel and solar cell
applications
■Selected models operate up to 500 V, suitable
for high voltage applications
■Built-in transient generator
■Short circuit test
■Built-in high resolution (0.1 mA/1 mV) voltage
and current measurement (models 8500 &
8502)
■Bright, easy to read display (VFD technology)
■Over-Current/Over-Voltage/Over-Power/Over-
Temperature Protection
■RS232 to TTL, USB to TTL serial
converter cables and application software
included
■List mode operation for increased throughput.
■Battery testing mode to provide A*hr rating
of battery (ending voltage level is adjustable)
■Flexible triggering: Create trigger events by
front panel keystroke, back panel TTL signal,
or software
■Remote voltage sensing to compensate for the
effect of voltage drop in wires.
■Store 25 instrument setups
■Thermostatically-controlled fans allow
operation in quiet environments with minimal
disruption
■All models are rack mountable. Compact 300
W and 600 W models for bench use
Applications:
■DC power supply testing
■Characterization of rechargeable batteries. A
battery test mode is provided that will measure
the ampere*hour (A*hr) characteristic of a
battery
■Fuel and solar cell test
■High voltage applications
Low voltage operation
The 8500 series can operate well below 1 V
which is important for low voltage application
such as fuel cell and solar cell testing. All models
can regulate (provide a stable input) down to
0.1 V. Model 8518, due to its particularly low
input resistance, can operate at full scale current
of 240 A at 1.2 V (see image)
Typical minimum operating voltage at full scale current:
8500 8502 8510 8512 8514 8518 8520 8522 8524 8526
1.05 V 3 V 1.8 V 3 V 1.92 V 1.2 V 10.8 V 3.6 V 1.56 V 1.8 V
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DC Electronic Loads
8500 Series
3
Rear panel
▲2
1) Air vents
Temperature-controlled fan expels air through
these vents to keep the temperature constant
inside the system.
2) Trigger and remote sensing terminal
block
Connect sensing lines to this terminal to
compensate for voltage drops due to load wire
resistance. This terminal block also contains the
two connections for the remote TTL trigger input
signal.
1
Front panel
▲1 2
3 4 5
The numeric keys and rotary knob provide a
convenient interface for setting the operating
mode and desired current/voltage/resistance
levels quickly and precisely. Voltage and current
can be set to a maximum resolution of 1 mV and
0.1 mA respectively (models 8500 and 8502
only). Up to 25 different instrument setups can
be stored and recalled from internal memory.
1) High resolution, easy to read display
Displays set values and measured values.
Current/voltage and power/resistance displays
can be toggled. Display resolution for current
and voltage is user-selectable. Maximum
resolution for model 8500 and 8502 is 1 mV/
0.1 mA.
2) Convenie nt data entry
Rotary knob for quick analog-style control. Turn
to adjust a setting value. Press to toggle
measurement display mode.
3) Numeric keypad
Conveniently enter set values directly and access
secondary functions.
4) Function k eys
Activate current, voltage, power, or resistance
modes and scroll through menus and options.
5) Front panel load terminals
Connect to device under test. Hex-head screw
Hex-head sc rew t erminals
3) Interface connection
Serial interface connector for RS232 or USB
communication.
4) Voltage switch
Line voltage selection switch (110 VAC or 220
VAC).
Terminals are used for models 8518 and
8520 – 8526 to connect wires.
3 4
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DC Electronic Loads
8500 Series
4
CC, CR, CV and CP mode
In Constant Current (CC) mode, the load will
sink a current according to the programmed
current value regardless of the input voltage.
(CC) mode can be used for load regulation
testing of DC power supplies or for characteriz-
ing the discharge profile of a battery.
Constant Power (CP) mode simulates a load
whose power consumption is independent of the
applied voltage. Constant Power (CP) mode is
useful for battery testing and simulating a
realistic discharge curve.
In Constant Voltage (CV) mode, the load will
attempt to sink enough current to control the
source voltage to the programmed value. This
mode is suitable for testing battery chargers.
In Constant Resistance (CR) mode, the load will
sink a current linearly proportional to the input
voltage in accordance with the programmed
Flexible operating modes
▲
Remote control & application software
▲
resistance. Unlike conventional resistors, the
load resistance stays constant regardless of the
power level.
Transient generator
The 8500 series offers a variable frequency
generator which can be used in all operating
modes. The DC load will toggle between 2
preset levels at a frequency between 0.1 Hz to
1 kHz, either continuously or controlled by a
trigger.
Trigg ered operation
Triggering is used to allow synchronization of the
DC Load's behavior with other events. You can
generate a trigger event by front panel keystroke,
by applying an external TTL signal to the back
panel terminal or by sending a commands over
the serial bus. The trigger can be used in pulse
mode, transient mode, list mode and works in
CC, CR, CV and CP modes.
The DC loads can be remotely controlled from
any PC with USB or RS232 interface, allowing
the user to fully program and monitor all
parameters. RS232 to TTL and USB to TTL
serial converter cables are included. For users
wanting to write their own custom software, a set
of example programs are available for download
on the B&K Precision website.
List Mode
A list of command sequences can be stored in
non-volatile memory and executed independently
of a computer. Execution in list mode greatly
reduces command processing time and computer
interaction during product testing. The command
sequence can be entered manually from the front
panel or downloaded from a PC via RS232 or
USB interface.
Application Software
The included Application Software supports front
panel emulation of the load and includes a
battery test application which provides A*hr
rating of a battery and adjustable ending voltage
levels (safety voltage).
Whether you are designing a device with
Nickel-Metal Hydride or Lithium-Ion batteries,
the 8500 series have the capabilities to test their
characteristics.
An example of battery discharge characteristics of an AA alkaline battery.
Model 8500
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DC Electronic Loads
8500 Series
5
Specifications
Models 8500 & 8502 (300 W)
▲
Models 8510/8512/8514/8518 (600 W & 1200 W)
▲
Models 8520/8522/8524/8526 (2400 W & 5000 W)
▲
Parameter Range Accuracy Resolution
8500 8502
CV Mode
Regulation
0.1-18 V ±(0.05%+0.02% FS) 1 mV
0.1 – 120 V 0.1 – 500 V ±(0.05%+0.025% FS) 10 mV
CC Mode
Regulation
0 – 3 A 0 – 3 A ±(0.1%+0.1% FS) 0.1 mA
0 – 30 A 0 – 15 A ±(0.2%+0.15% FS) 1 mA
Current Measurement
0 – 3 A 0 – 3 A ±(0.1% + 0.1% FS) 0.1 mA
0 – 30 A 0 – 15 A 8500: ±(0.2%+0.15% FS)
8502: ±(0.2%+0.3% FS) 1 mA
Voltage Measurement 0-18 V ±(0.02% + 0.02% FS) 1 mV
0-120 V 0 – 500 V ±(0.02% + 0.025% FS) 10 mV
Parameter 8510 8512 8514 8518
Input rating
Voltage 0 – 120 V 0 – 500 V 0 – 120 V 0 – 60 V
Current 0 – 120 A 0 – 30 A 0 – 240 A 0 – 240 A
Power 600 W 1200 W
Parameter 8520 8522 8524 8526
Input rating
Voltage 0 – 120 V 0 – 500 V 0 – 60 V 0 – 500 V
Current 0 – 240 A 0 – 120 A 0 – 240 A 0 – 120 A
Power 2400 W 5000 W
Parameter 8500 8502
Input rating
Voltage 0 – 120 V 0 – 500 V
Current 0 – 30 A 0 – 15 A
Power 300 W
Parameter Range Accuracy Resolution
8510 8512 8514 8518
CV Mode
Regulation
0.1-18 V ±(0.05%+0.02% FS) 1 mV
0.1 V to Vmax ±(0.05%+0.025% FS) 10 mV
CC Mode
Regulation
0-12 A 0-3 A 0-24 A ±(0.1%+0.1% FS) 1 mA
0 – max Current ±(0.2%+0.15% FS) 10 mA
Current
Measurement
0-12 A 0-3 A 0-24 A ±(0.1% + 0.1% FS) 1 mA
0 – max. Current ±(0.2%+0.15% FS) 10 mA
Voltage
Measurement
0 – 18 V 8510/8514: (0.02% + 0.025% FS)
8512/8518: (0.02% + 0.02% FS) 1 mV
0 - Vmax ±(0.02% + 0.025% FS) 10 mV
Parameter Range Accuracy Resolution
8520 8522 8524 8526
CV Mode
Regulation
0.1-18 V ±(0.05%+0.02% FS) 1 mV
0.1 V to Vmax ±(0.05%+0.025% FS) 10 mV
CC Mode
Regulation
0-24 A 0-12 A 0-24 A 0-12 A ±(0.1%+0.1% FS) 1 mA
0 – max Current ±(0.2%+0.15% FS) 10 mA
Current
Measurement
0-24 A 0-12 A 0-24 A 0-12 A ±(0.1% + 0.1% FS) 1 mA
0 – max. Current ±(0.2%+0.15% FS) 10 mA
Voltage
Measurement
0 – 18 V 8522/8526: (0.02% + 0.02% FS)
8520/8524: (0.02% + 0.025% FS) 1 mV
0 - Vmax ±(0.02% + 0.025% FS) 10 mV
Specifications
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DC Electronic Loads
8500 Series
6
Common characteristics
▲
v102714
Standard Power cord, user manual, installation CD with application software, RS232 to TTL serial converter cable IT-E131,
USB to TTL serial converter cable IT-E132, certificate of calibration and test report
Optional Rack mount kit IT-E151 for models 8500, 8502, 8510, 8512, 8514 and 8518 only
Model Dimensions (W x H x D) Weight
8500 8.46” x 3.46” x 14” (215 mm x 88 mm x 355 mm) 11.5 lb (5.2 kg)
8502 8.46” x 3.46” x 14” (215 mm x 88 mm x 355 mm) 11.5 lb (5.2 kg)
8510 16.9” x 3.46” x 14” (429 mm x 88 mm x 355 mm) 31 lb (14 kg)
8512 16.9” x 3.46” x 14” (429 mm x 88 mm x 355 mm) 31 lb (14 kg)
8514 16.9” x 3.46” x 14” (429 mm x 88 mm x 355 mm) 31 lb (14 kg)
8518 16.9” x 3.46” x 14” (429 mm x 88 mm x 355 mm) 31 lb (14 kg)
8520 17.48” x 7.09” x 21.22” (444 mm x 180 mm x 539 mm) 66 lb (30 kg)
8522 17.48” x 7.09” x 21.22” (444 mm x 180 mm x 539 mm) 66 lb (30 kg)
8524 17.48” x 14.06” x 21.22” (444 mm x 357 mm x 539 mm) 148 lb (67 kg)
8526 17.48” x 14.06” x 21.22” (444 mm x 357 mm x 539 mm) 148 lb (67 kg)
Parameter Range Accuracy Resolution
CR Mode Regulation
(Input current ≥FS 10%
Input voltage≥FS 10%)
0.1 -10 Ω±(1%+0.3% FS) 0.001 Ω
10-99 Ω±(1%+0.3% FS) 0.01 Ω
100-999 Ω±(1%+0.3% FS) 0. 1 Ω
1K-4 KΩ±(1%+0.8% FS) 1 Ω
CW Mode Regulation
(Input current ≥FS 10%
Input voltage≥FS 10%)
0-100 W ±(1%+0.1% FS) 1 mW
100 W - max power ±(1%+0.1% FS) 100 mW
Power Measurement
(Input current ≥ FS 10%
Input voltage ≥ FS 10%)
0-100 W ±(1%+0.1% FS) 1 mW
100 W - max power ±(1%+0.1% FS) 100 mW
Other
Battery testing function Input = 0.1 V – 120 V, Max measurement capacity = 999 Ah
Resolution = 10 mA, Timer range = 1-60000 sec
Transition mode Range of Frequency 0.1 Hz-1 kHz, Frequency error rate 0.5%
* All 8500 series models, with the exception of models 8524 and 8526, can be configured for 110 V or 220 V operation via the AC line switch in the rear
panel. Base models 8524 and 8526 operate with 110 V only. For 220 V operation, order model 8524-220V or 8526-220V respectively. “-220V” denotes
220 V operation only and these models cannot be reconfigured for 110 V operation.
Mechanical specifications
Accessories
AC input 110 / 220 (see note below)* VAC ± 10%, 47 – 63 Hz
Operating temperature 32 ºF - 104 ºF (0 - 40 ºC)
Storage temperature 50 ºF - 140 ºF (10 - 60 ºC)
Humidity ≤ 95% relative humidity, non-condensing
Safety EN61010-1:2001, EU Low Voltage Directive 73/23/EEC amended by 93/68/EEC
Electromagnetic compatibility Meets EMC Directive 89/336/EEC amended by 93/68/EEC, EN50081-1, EN50082-1
One-Year Warranty
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