BK Precision 8526, 8524, 8522, 8520, 8518 User Manual
...
USER MANUAL
8500 SERIES DC ELECTRONIC LOADS
Models 8500, 8502, 8510, 8512, 8514, 8518, 8520,
8522, 8524 & 8526
Safety
WARNING
CAUTION
The following general safety precautions must be observed during all phases of operation of this instrument.
Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety
standards of design, manufacture, and intended use of the instrument. B&K Precision assumes no liability for
the customer’s failure to comply with these requirements.
Verify that all safety precautions are taken. Note the instrument's external markings described under "Safety
Symbols".
This product is a Safety Class 1 instrument, which means it is provided with a protective earth terminal. To
minimize shock hazard, the instrument chassis and cover must be connected to an electrical ground. The
instrument must be connected to the AC line power through a grounded power cable, with the ground wire
firmly connected to an electrical ground (safety ground) at the power outlet. Note: Any interruption of the
protective (grounding) conductor or disconnection of the protective earth terminal will cause a potential shock
hazard that could result in personal injury.
DO NOT OPERATE THE INSTRUMENT IN AN EXPLOSIVE ATMOSPHERE OR IN THE PRESENCE OF
FUMES OR FLAMMABLE GASES.
KEEP AWAY FROM LIVE CIRCUITS.
Operating personnel must not remove instrument covers. Component replacement and internal adjustments
must be made only by qualified service personnel. Do not replace components with the power cable
connected. Under certain conditions, dangerous voltages may exist even with the power cable removed. To
avoid injuries always disconnect power, discharge circuits and capacitors, and remove external voltage
sources before touching components.
DO NOT SERVICE OR ADJUST ALONE.
Do not try to perform internal service or adjustment unless another person capable of rendering first aid and
resuscitation is present.
Safety Symbols
Note the instrument's external markings as follows:
Direct current
Alternating current
Both direct and alternating current
Protective earth (ground) terminal
Caution (refer to accompanying documents)
The WARNING sign denotes a hazard. It calls attention to a procedure, practice,
or the like which, if not correctly performed or adhered to, could result in
personal injury. Do not proceed beyond a WARNING sign until the indicated
conditions are fully understood and met.
The CAUTION sign denotes a hazard. It calls attention to an operating
procedure, or the like, which, if not correctly performed or adhered to, could
result in damage to or destruction of part or all of the product. Do not proceed
beyond a CAUTION sign until the indicated conditions are fully understood and
met.
8500 DC Load Series Version: February 4, 2009 Page 2 of 76
Table of Contents
Safety......................................................................................................................................................2
Safety Symbols...................................................................................................................................2
Notation...................................................................................................................................................5
Quick reference......................................................................................................................................6
Model numbers covered by this document..........................................................................................6
Options and accessories.....................................................................................................................6
Overview of instrument.......................................................................................................................6
Typical tasks.......................................................................................................................................7
Front panel..........................................................................................................................................7
Standard display.................................................................................................................................9
Front panel keys.................................................................................................................................9
Rear panel........................................................................................................................................10
Display annunciators.........................................................................................................................11
Menus...............................................................................................................................................11
Specifications........................................................................................................................................15
Environmental Conditions ................................................................................................................16
Internal Resistances.....................................................................................................................17
Operational power curve..............................................................................................................17
Low Voltage Characteristics.........................................................................................................18
Slew rate......................................................................................................................................19
Glossary................................................................................................................................................21
Installation.............................................................................................................................................23
Inspection.........................................................................................................................................23
Items you should have received...................................................................................................23
Instrument location............................................................................................................................23
Outline Drawings...............................................................................................................................23
Bench operation................................................................................................................................26
First turn-on checkout.......................................................................................................................27
Operational introduction....................................................................................................................28
Power-on state..................................................................................................................................29
Constant current mode.....................................................................................................................29
Constant voltage mode.....................................................................................................................30
Constant power mode.......................................................................................................................30
Constant resistance mode................................................................................................................31
Timed operation................................................................................................................................31
Changing display resolution..............................................................................................................32
Increasing current resolution........................................................................................................32
Increasing voltage resolution........................................................................................................32
Short.................................................................................................................................................32
Battery test........................................................................................................................................32
Transient operation...........................................................................................................................33
Continuous transient operation.....................................................................................................33
Pulse transient operation..............................................................................................................34
Toggled transient operation..........................................................................................................35
Toggle between two test values...................................................................................................36
Lists (dynamic condition)...................................................................................................................36
Test files...........................................................................................................................................37
8500 DC Load Series Version: February 4, 2009 Page 3 of 76
Triggering..........................................................................................................................................39
Voltage threshold operation..............................................................................................................40
Passwords........................................................................................................................................40
Protection features............................................................................................................................40
Over Voltage protection................................................................................................................41
Over Current protection................................................................................................................41
Over Power protection .................................................................................................................41
Reverse voltage protection...........................................................................................................41
Over Temperature protection.......................................................................................................42
Remote sensing................................................................................................................................42
Saving and Recalling settings...........................................................................................................43
Remote operation..................................................................................................................................44
Communication cables......................................................................................................................44
RS232 to TTL serial converter cable IT-131 (standard)................................................................44
USB to TTL serial converter cable IT-132 (option)........................................................................44
RS-232 settings................................................................................................................................45
Overview of DC Load programming..................................................................................................45
Packet structure...........................................................................................................................45
Status packets..............................................................................................................................46
Chapter organization....................................................................................................................48
Summary of commands....................................................................................................................49
Command details..............................................................................................................................51
Serial number and firmware version......................................................................................................71
In case of trouble...................................................................................................................................72
Instrument won't turn on....................................................................................................................72
Error messages during power-up......................................................................................................72
Keypad unlock procedure (Keypad was accidentally locked)............................................................72
Appendix: Service and warranty information.........................................................................................74
Index.....................................................................................................................................................75
8500 DC Load Series Version: February 4, 2009 Page 4 of 76
Notation
I-set Represents a key on the front panel. Note that some of these may be
accessed in combination with the Shift key.
OFF Annunciator, value, or message shown on the vacuum fluorescent
display.
CONFIG Menu item
OFF
Default menu item
8500 DC Load Series Version: February 4, 2009 Page 5 of 76
Quick reference
Model numbers covered by this document
The B&K Precision DC Loads covered by this manual are:
● 8500
● 8502
● 8510
● 8512
● 8514
● 8518
● 8520
● 8522
● 8524
● 8526
Unless otherwise noted, this document will refer to all of these instruments as the DC Load.
Instrument differences, where appropriate, will be noted.
Options and accessories
The items included with the instrument are:
1. Power cord
2. User manual
3. Installation CD with application software PV8500 and USB driver for optional TTL to USB
adapter
4. TTL to RS232 serial converter IT-131
5. Test report
Optional accessories are:
6. rack mount kit IT-E151
7. TTL to USB serial adapter IT-132
Overview of instrument
The DC Load is a two terminal device that can be connected to DC sources. Here, a DC source is a
voltage that is always positive on the DC Load's + terminal referenced to the - terminal.
DC Electronic Loads are used for design, manufacturing and evaluation of DC power supplies,
batteries, and power components. Other applications include fuel-cell and photovoltaic cell test. The
DC Load can operate under the following modes:
● Draw a constant voltage from a DC source.
● Draw a constant current from a DC source.
● Draw a constant power from a DC source.
● Present a constant resistance to the DC source (this behavior simulates a perfect resistor
8500 DC Load Series Version: February 4, 2009 Page 6 of 76
whose resistance doesn't change as a function of current or voltage).
The DC Load can present dynamically changing loads to the DC source with millisecond switching
times. The DC Load can be remotely programmed via a serial interface (RS-232 or USB). Versatile
triggering options allow the dynamic load behavior to be synchronized with other events.
A battery test mode is provided that will measure the ampere*hour (A*hr) characteristic of a battery.
Shorts can be simulated by either the front panel or custom programming. The DC source or other
components can be protected from excessive voltage, current, or power, which will cause the DC
Load to shut down if excessive levels or reverse polarity are detected.
Dynamic profiles and last instrument states can be stored in non-volatile memory.
The DC Load is a versatile instrument for static and dynamic testing of power supplies, batteries, DC
to DC converters, and battery chargers.
Typical tasks
To perform the following tasks, consult the indicated sections
Task Section(s)
Manual on/off CC, CV, CW, or CR test Constant current mode
Constant voltage mode
Constant power mode
Constant resistance mode
Timed on/off CC, CV, CW, or CR test Constant current mode
Constant voltage mode
Constant power mode
Constant resistance mode
Timed operation
Triggered CC, CV, CW, or CR test Constant current mode
Constant voltage mode
Constant power mode
Constant resistance mode
Triggering
Constant load with one transient Transient operation
Load with multiple transients Lists (dynamic condition)
Determine A*hr characteristic of battery Battery test
Run a sequence of tests Test files
Front panel
The following picture is the front panel for the 8510 DC Load. All models have the same front panel,
only the terminal section will vary based on the model.
8500 DC Load Series Version: February 4, 2009 Page 7 of 76
6
1
2
3 4 5
1
2
3
4
5
6
Button Function(s)
16-character display shows voltage and current measurements.
Rotary knob. Turn to adjust a setting value. Press in to toggle between setting the
currently-selected mode's value and reading the voltage and current, as shown in
the above picture.
Power switch to turn the instrument on or off.
Numeric keypad:
Numeric entry keys.
Secondary key functions.
Keypad:
Enable/disable input.
Set up the current, voltage, power, and resistance modes.
Scroll through menus and options.
Input terminals. Depending on the model, you will have different types and
numbers of input terminals.
Models 8500/8502 come with one plus and one minus terminal
Models 8510/8512 come with two positive and two negative terminals however
each terminal is able to sink the maximum current supported by the instrument.
Thus, it is not necessary to double up on the wires when sinking a high current
unless you wish to.
Models 8514/8518 also come with two positive and two negative terminals however
it is required to double up on the wires when sinking a current exceeding 120A.
Models 852x come with a screw terminal block to connect the wires
8500 DC Load Series Version: February 4, 2009 Page 8 of 76
Standard display
1
4
2
8 9
6 05
7
3 ESC
I-set V-set
R-set
Input on/off
Shift
P-set ENTER
POWER
A B
Tran
Store Recall S-Tran Menu
Local Battery Short Trigger
The standard display for the instrument is the voltage and current at the instrument's terminals. You
may press the △ or ▽ keys to see the instantaneous power and the mode's parameter setting.
Standard display
Front panel keys
V-set Choose constant voltage mode.
I-set Choose constant current mode.
P-set Choose constant power mode.
R-set Choose constant resistance mode.
Set the current mode's load value from the A value of the
Shift + A
corresponding transient operation. See the Transient
operation section. This key does not work when the
TRAN annunciator is on.
Set the current mode's load value from the B value of the
Shift + B
corresponding transient operation. See the Transient
operation section. This key does not work when the
TRAN annunciator is on.
Shift + Store
Shift + Recall
8500 DC Load Series Version: February 4, 2009 Page 9 of 76
Store the DC Load state in non-volatile memory. You may
store 25 different states.
Recall the DC Load state from non-volatile memory. You
may recall 25 different states.
Shift + Menu Enter the instrument's menu system.
4
1
23
1
2
3
Shift + Short Turn short circuit on or off.
Shift + Tran Start or stop transient condition.
Shift + Trigger Causes an immediate trigger.
Shift + Battery
Shift + S-Tran Set transient condition parameters.
On/Off
Shift
△ Scroll up key.
▽ Scroll down key.
0 to 9 Enter the digits 0 to 9.
• Decimal point.
Esc
Enter Enter the selected value or setting.
Turn on or off battery testing function (measures battery
capacity in ampere*hours).
Turns DC Load ON or OFF (OFF is high impedance
state).
The shift key is used to select the alternate operation of a
key, indicated by the word under the key.
The escape key. It can be used to exit keyboard entry or
move up a level in the menu.
Rear panel
Your instrument's rear panel may look different from the following figure, but the same functionality
will be present.
3 pin IEC320 AC input connector.
4 pin trigger and remote sensing connector.
9-Pin serial port interface connector. NOTE: This port's terminals utilize 5 volt
TTL logic signals. Do NOT connect an RS-232 cable with standard RS-232
voltages on the cables connectors. Doing so may damage the instrument and is
8500 DC Load Series Version: February 4, 2009 Page 10 of 76
not covered by warranty.
4
Line voltage selection switch (110 VAC or 220 VAC)
Display annunciators
Annunciator Meaning
OFF The load is off.
UNREG The input is unregulated.
CC Constant current mode.
CV Constant voltage mode.
CW Constant power mode.
CR Constant resistance mode.
PROT Not used.
TRAN Transient operation is enabled.
LIST List mode is initiated or running.
SENSE Remote sensing is on.
LIMIT Not used.
ERROR An error has occurred.
The instrument is communicating with an IT-E131 or IT-E132
LINK
RMT
SHIFT The Shift key has been pressed.
LOCK The keyboard is locked by a password.
communications adapter. This annunciator will stay lit for
approximately 3 seconds after the last remote communication with
the DC Load.
Instrument is in the remote state. The only active key is the Local
key. This is set with the 0x20 remote command (see the Remote
programming section).
Menus
Use Shift + Menu to enter the menus. “Lvl” indicates the menu level, which is also indicated by the
indentation of the menu item text. Scroll through the menu items using the △ and ▽ keys. Return to
a previous menu level by pressing the Esc key. Words in the heavy font such as OFF indicate the
default menu selection.
Lvl Menu item Function
1 CONFIG
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Lvl Menu item Function
2 INITIAL CONFIG Return instrument to factory default settings.
2 POWER-ON RECALL Power on state of instrument.
3 ON Remembers state at last power-down.
3
OFF
Does not remember state at last power-down.
2 INPUT RECALL Remember whether load was ON
If load was ON prior to turning the power off, the ON
3 ON
state will be resumed after power on. POWER-ON
RECALL must also be on for this to work.
3
OFF
After power on, the instrument will be in the OFF state.
2 KEY SOUND SET
3
ON
Enable audible beep when key is pressed.
3 OFF No sound when key is pressed.
2 KNOB LOCK SET
3 ON Rotary knob is non-functional.
3
OFF
2 SHORT CUT RECALL
3 ON
3
OFF
Rotary knob is functional.
Quickly recall a setup register by pressing a number
key.
Allows quick recall of a setup by pressing the number
key.
Pressing a number key does not recall a setup.
2 RANGE SELECT Change the precision of displayed values.
Allows the user to select the instrument's range, giving
3 ON
better voltage and/or current resolution. Press
Shift + △ or Shift + ▽ to toggle resolutions.
3
OFF
Current and voltage measurement resolution are fixed.
2 REMOTE SENSE See the Remote sense section.
3 ON Remote sensing is on.
3
OFF
Remote sensing is off.
2 ADC UPDATE RATE Set the rate at which the display is updated.
3 HIGH
3
LOW
2 TRIGGER SOURCE How the instrument is triggered.
3
IMMEDIATE
3 EXTERNAL
Triggered from the Shift + Trigger key.
Triggered from a TTL high signal (longer than 5 ms) at
the trigger connector on rear panel.
3 BUS Triggered from a serial bus command.
2 CONNECT MODE
3 MAXTIPLEXING
3
8500 DC Load Series Version: February 4, 2009 Page 12 of 76
SEPARATE
Not supported with this hardware. (Should actually say
"multiplexing".)
Lvl Menu item Function
2 BAUDRATE SET Set the serial bus connection speed.
3
4800
3 9600
3 19200
3 38400
2 COMM. PARITY SET Serial connection parity.
3
NONE
3 EVEN
3 ODD
2 ADDRESS SET
Set the instrument's address. Must be an integer
between 0x00 and 0xFE inclusive.
Set the instrument's password to 1 - 4 digits. Press the
Enter key without any data entry to remove the
2 KEY LOCK SET
password. If you accidentally locked the keyboard,
follow instructions at the end of this manual, chapter “in
case of trouble” to unlock the keypads.
2 EXIT Return to prior menu level.
1 SYSTEM SET
Set the maximum allowed current. Exceeding this
2 MAX CURRENT SET
value will cause the load to shut off. This value also
becomes the maximum current you can set.
Set the maximum allowed power. Exceeding this value
2 MAX POWER SET
will cause the load to shut off. This value also becomes
the maximum power you can set.
Set the maximum allowed voltage. Exceeding this
2 MAX VOLTAGE SET
value will cause the load to shut off. This value also
becomes the maximum voltage you can set.
2 VOLTAGE ON SET
2 VOLTAGE OFF SET
Used to set an ON voltage threshold. See the Voltage
threshold section.
Used to set an OFF voltage threshold. See the
Voltage threshold section.
2 EXIT Return to prior menu level.
1 LIST SET Lists are programmed sequences of load values.
2 MODE SET
3 FIXED MODE Load characteristics set by front panel.
3 LIST MODE
Load characteristics are dynamic and controlled by a
list stored in memory.
2 CALL LIST FILE Recall an existing list from nonvolatile memory.
3 RECALL N N is list number.
2 EDIT LIST FILE
Note that each list file has four lists, one for each
operation mode (CC, CV, CW, CR).
3 CURRENT LIST
4 ONCE List is executed once per trigger.
8500 DC Load Series Version: February 4, 2009 Page 13 of 76
Lvl Menu item Function
4 REPEAT List is repeatedly executed after the trigger is received.
3 VOLTAGE LIST
4 ONCE List is executed once per trigger.
4 REPEAT List is repeatedly executed after the trigger is received.
3 POWER LIST
4 ONCE List is executed once per trigger.
4 REPEAT List is repeatedly executed after the trigger is received.
3 RESISTANCE LIST
4 ONCE List is executed once per trigger.
4 REPEAT List is repeatedly executed after the trigger is received.
2 CALL TEST FILE Recalls a stored test file (see Test files section).
3 RECALL N N is file number.
2 EDIT TEST FILE See Test files section for more details.
Set how the nonvolatile memory is partitioned to store
2 LIST STORE MODE
lists. You can choose between numerous short lists or
fewer longer lists.
3 8 X 120 STEPS
3 4 X 250 STEPS
3 2 X 500 STEPS
3 1 X 1000 STEPS
2 EXIT Return to prior menu level.
1 LOAD ON TIMER Enable a timed load.
2 TIMER STATE
When the load timer is enabled by this menu element,
3 ON
the load is turned on when the On/Off key is pressed.
After the set time period has elapsed, the load is turned
off.
3
OFF
2 TIMER SET
When the load is turned on via the On/Off key, the load
stays ON indefinitely.
Set the time period from 1 to 60000 s for the load to be
on.
2 EXIT Return to prior menu level.
1 EXIT Return to standard display.
8500 DC Load Series Version: February 4, 2009 Page 14 of 76
Models 8500 & 8502 (300 W)
Parameter 8500 8502
Voltage 0 to 120 V 0 to 500 V
Input rating
Parameter Range
CV Mode
Regulation
CC Mode
Regulation
Current Measurement
Voltage Measurement
Current 1 mA to 30 A 1 mA to 15 A
Power 300 W
8500 8502
0.1 – 120 V 0.1 – 500 V ±(0.05%+0.025% FS) 10 mV
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
0 – 3 A 0 – 3 A ±(0.1% + 0.1% FS) 0.1 mA
0 – 30 A 0 – 15 A
0-120 V 0 – 500 V ±(0.02% + 0.025% FS) 10 mV
Specifications
8500/8502 common characteristics
Accuracy Resolution
0.1-18 V ±(0.05%+0.02% FS) 1 mV
8500: ±(0.2%+0.15% FS)
8502: ±(0.2%+0.3% FS)
0-18 V ±(0.02% + 0.02% FS) 1 mV
1 mA
Models 8510/8512/8514/8518 (1200 & 2400 W)
Parameter 8510 8512 8514 8518
Voltage 0 – 120 V 0 – 500 V 0 – 120 V 0 – 60 V
Input rating
Parameter
CV Mode
Regulation
CC Mode
Regulation
Current Measurement
Voltage Measurement
Current 0 – 120 A 0 – 30 A 0 – 240 A 0 – 240 A
Power 600 W 1200 W
8510/8512/8514/8518 common characteristics
Range
8510 8512 8514 8518
0.1-18 V ±(0.05%+0.02% FS) 1 mV
0.1 V to Vmax ±(0.05%+0.025% FS) 10 mV
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
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
0 – 18 V
0 - Vmax ±(0.02% + 0.025% FS) 10 mV
Accuracy Resolution
8510/8514:
(0.02% + 0.025% FS)
8512/8518:
(0.02% + 0.02% FS)
1 mV
8500 DC Load Series Version: February 4, 2009 Page 15 of 76
Models 8520/8522/8524/8526 (2400W & 5000W)
Parameter 8520 8522 8524 8526
Voltage 0 – 120 V 0 – 500 V 0 – 60 V 0 – 500 V
Input rating
Parameter
CV Mode
Regulation
CC Mode
Regulation
Current Measurement
Voltage Measurement
Current 0 – 240 A 0 – 120 A 0 – 240 A 0 – 120 A
Power 2400 W 5000 W
8520/8522/8524/8526 common characteristics
Range
8520 8522 8524 8526
0.1-18 V ±(0.05%+0.02% FS) 1 mV
0.1 V to Vmax ±(0.05%+0.025% FS) 10 mV
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
0-12 A 0-3 A 0-24 A 0-12 A ±(0.1% + 0.1% FS) 1 mA
0 – max. Current ±(0.2%+0.15% FS) 10 mA
0 – 18 V
0 - Vmax ±(0.02% + 0.025%FS) 10 mV
All DC load models
common characteristics for all DC load models
Parameter Range Accuracy Resolution
CR Mode Regulation
Input current ≥FS 10%
Input Voltage≥FS 10%
CW Mode Regulation
Input current ≥FS 10%
Input Voltage≥FS 10%
Power Measurement
Input current ≥ FS 10%
Input Voltage ≥ FS 10%
Battery testing function
Transition Mode
Range of Frequency 0.1 Hz-1 kHz Frequency error rate＜0.5%
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
0-100 W ±(1%+0.1% FS) 1 mW
100 W – max Power ±(1%+0.1% FS) 100 mW
0-100 W ±(1%+0.1% FS) 1 mW
100-max Power ±(1%+0.1% FS) 100 mW
Input=0.1 V – 120 V Max measurement capacity= 999 A/H
Resolution =10 mA Timer range=1~60000 sec
Accuracy Resolution
8522/8526:
(0.02% + 0.02% FS)
8520/8524:
(0.02% + 0.025% FS)
1 mV
NOTE: Specifications and information are subject to change without notice. Please visit
www.bkprecision.com for the most current product information.
Environmental Conditions
This instrument is intended for indoor use in a pollution degree 2 environment. Operating
environmental limits are as follows:
8500 DC Load Series Version: February 4, 2009 Page 16 of 76
Parameter Specification
Humidity ≤ 95% relative humidity, non-condensing
Altitude ≤ 2000 m
AC Line voltage
220 AV±10%，47～63 Hz
110 AV±10%，47～63 Hz
Operating temperature
Storage temperature
0 – 40 ºC
-10 – 60 ºC
Internal Resistances
The internal resistances of the DC load models are less than or equal to the following values:
Model Internal
Resistance(mΩ)
8500 ≤ 35
8502 ≤ 200
8510 ≤ 15
8512 ≤ 100
8514 ≤ 8
8518 ≤ 5
8520 ≤ 45
8522
8524 ≤ 6.5
8526 ≤ 15
Operational power curve
The DC load's output follows a power curve illustrated below:
≤ 30
8500 DC Load Series Version: February 4, 2009 Page 17 of 76
The curved portion is where the dissipated power is at the rated power of the instrument (and is
actually a hyperbolic shape). When you use the menu to set lower-than-maximum power or current,
the operating region may look like the following:
Note the gap between the operating region and the current axis for lower voltages. More detail is
described in the following section.
Low Voltage Characteristics
The following graphs show the voltage/current relationships for low voltages:
8500 DC Load Series Version: February 4, 2009 Page 18 of 76
Slew rate
The slew rate for each DC load varies from model to model. The variations are also dependent on
the different regions measured for each individual load. In general, the slew rate for low current
transitions, say 0 to 0.5 A, is significantly lower than slew rate for current transitions from 30 to 70 A.
The provided table below indicates measured slew rates based on the maximum range of current
transition of the models are capable of. For example, model 8500's slew rate would be measured
with current transition from 0 A to 30 A.
Note: The graph below illustrates slew rate measurements. In general, the indicated slew rates in
the table below are measured based on the maximum current range each model is able to handle.
Between the 10% and 90% region, the slew rate can be measured by observing the steepest slope
portion. The indicated measured time would be used to calculate the slew rate. Hence, the slew
rate calculation is simply (rated max. current – 0 A) / T, where T is the measured time from 10% to
90% region and rated max. current is the specified maximum current of each load.
8500 DC Load Series Version: February 4, 2009 Page 19 of 76
As a reference, below is a table of slew rates for their respective models:
0.5A / S
0.5A / S
1A/ S
0.5A / S
1A/ S
1A/ S
1A/ S
1A/ S
1A/ S
1A/ S
Model Slew rate
8500
8502
8510
8512
8514
8518
8520
8522
8524
8526
8500 DC Load Series Version: February 4, 2009 Page 20 of 76
Glossary
△ Up arrow key. Used to scroll through the menu or cause the temporary
display of the alternate standard display.
▽ Down arrow key. Used to scroll through the menu or cause the temporary
display of the alternate standard display.
A Value for first setting of transient mode.
B Value for second setting of transient mode.
Battery Select battery testing mode. See Battery test section.
CC Constant current
Condition Steady state, transient, or dynamic. Steady state condition means the
load mode is operated in a steady state. Transient condition means the
load mode is switched between two values with user-selectable timing.
Dynamic means multiple levels and timings are available (and are gotten
by using lists).
CR Constant resistance
CV Constant voltage
CW Constant power
Dynamic condition See Condition.
Enter Choose the indicated value or setting.
Esc Stop current entry and go to previous menu level.
I-set Configure the instrument for constant current mode.
Knob click Press the knob in until it clicks. This is an alternate method for changing
settings.
Link This annunciator will light up when communications are coming in across
the serial interface. It will stay lit for approximately 3 seconds after the
last command was received.
List A list is a stored sequence of test parameter and test duration values.
These are used for dynamic load profiles.
Local Returns control to the front panel.
Menu Show the top level item of the instrument's menus.
Mode Mode of operation of the instrument. The four modes are CC, CV, CW,
and CR.
Mode settings Parameter values for CC, CV, CW, and CR modes.
On/Off Manually toggle the instrument between its set mode and an infinite
impedance state.
P-set Configure the instrument for constant power mode.
Power Power switch to turn the instrument on and off.
8500 DC Load Series Version: February 4, 2009 Page 21 of 76
R-set Configure the instrument for constant resistance mode.
Recall Recall instrument state from non-volatile memory.
Remote sensing Allows the instrument to measure the load power properly in case of large
currents by sensing the voltage at the source, rather than at the
instrument's terminals. This removes the effect of the resistance of long
leads.
S-Tran Set parameters (A, B, and transition times) for transient mode.
Shift Shift key, which allows access to the functions written beneath the
number keys.
Short Toggles between normal operation and a low resistance short.
Store Allows the user to save the instrument state in non-volatile memory.
Test file A sequence of different test modes used for automated testing.
Tran Set to transient condition.
Transient condition See Condition.
Trigger The key that causes an immediate trigger.
V-set Configure the instrument for constant voltage mode.
VFD Vacuum fluorescent display, the technology used for the instrument's
display.
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Installation
CAUTION
Inspection
Items you should have received
When you open the box containing the instrument, you should find the following items:
1. The DC Load instrument
2. Power cord
3. User manual
4. Installation CD with application software PV8500
5. TTL to RS-232 serial converter IT-131
6. Calibration report
Instrument location
This instrument is intended for indoor use in a pollution degree 2 environment. Please refer to the
specifications table for the allowable environment operating limits.
Significant power may be dissipated in the DC Load, which includes one or more thermostaticallyoperated fans. The fans draw air through the bottom and sides and exhaust it out the back. It is
important to allow at least 25 mm (1 inch) of clearance on all sides of the instrument so adequate
cooling airflow can be maintained.
Outline Drawings
All dimensions are in millimeters (mm).
Models: 8500& 8502
Do not block the fan exhaust at the rear of the load.
8500 DC Load Series Version: February 4, 2009 Page 23 of 76
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