Unit UTL8500 Series User manual

UTL8500 Series
Programmable DC Electronic Load
User Manual

UTL8500 Series User Manual
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Preface
Thank you for purchasing this brand new product. In order to use this product safely and
correctly, please read this manual thoroughly, especially the safety notes.
After reading this manual, it is recommended to keep the manual at an easily accessible
place preferably close to the device, for future reference.
Copyright Information
Uni-Trend Technology (China) Co., Ltd. all rights reserved.
UNI-T is the registered trademark of Uni-Trend Technology (China) Co., Ltd.
UNI-T products are protected by patent rights in China and other countries, including
issued and pending patents. Uni-Trend reserves the rights to any productspecification and
pricing changes.
Uni-Trend reserves all rights. Information in this manual supersedes all previously
published versions. No part of this manual may be copied, extracted or translated by any
means without the prior permission of Uni-Trend.
Warranty Service
The instrument has a warranty period of one year from the date of purchase. If the
instrument is damaged due to improper operation by the user during the warranty period,
the maintenance fee and the costs caused by the maintenance shall be borne by the user,
and the instrument shall be maintained by the company for life.
If the original purchaser sells or transfers the product to a third party within one year
from the date of purchase of the product, the warranty period of one year shall be from the
date of the original purchase from UNI-T or an authorized UNI-T distributor. Power cords,
accessories and fuses, etc. are not included in this warranty.
If the product is proved to be defective within the warranty period, UNI-T reserves the
rights to either repair the defective product without charging of parts and labor, or exchange
the defected product to a working equivalent product (determined by UNI-T). Replacement
parts, modules and products may be brand new, or perform at the same specifications as
brand new products.All original parts, modules, or products which were defective become

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the property of UNI-T.
The “customer” refers to the individual or entity that is declared in the guarantee. In
order to obtain the warranty service, "customer" must inform the defects within the
applicable warranty period to UNI-T, and perform appropriate arrangements for the
warrantyservice. The customer shall be responsible for packing and shipping the defective
products to the designated maintenance center of UNI-T, pay the shipping cost, and
provide a copy of the purchase receipt of the original purchaser. If the product is shipped
domestically to the location of the UNI-T service center, UNI-Tshall pay the return shipping
fee. If the product is sent to any other location, the customer shall be responsible for all
shipping, duties, taxes, and any other expenses.
Guarantee Limit
This warranty shall not apply to any defects, malfunction or damages caused by
accidental, machine parts’wear and tear, using outside the product’s specifications,
improper use, and improper or lacking of maintenance. UNI-T under the provisions of this
warranty has no obligation to provide the following services:
a) Any repair damage caused by the installation, repair, or maintenance of the product by
non UNI-T service representatives;
b) Any damage caused by improper use or connection to an incompatible device;
c) Any damage or malfunction caused by the use of a power source not provided by UNI-
T;
d) Anymaintenance on altered or integrated products (if such alteration or integration leads
to an increase in time or difficulty of product maintenance).
This warranty is written by UNI-T for this product and it is used to substitute any other
express or implied warranties. UNI-Tand its distributors do not offer any implied warranties
for merchantability or applicability purposes. For violation of this guarantee, UNI-T is
responsible for the repair or replacement of defective products as the only and complete
remedy available to customers. Regardless of whether UNI-T and its distributors are
informed that any indirect, special, incidental, or consequential damage may occur, the
UNI-T and its distributors shall not be responsible for any of these damages.
Safety Information
Warning Caution: to avoid specifies conditions and actions that may pose hazards

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to the user, be sure to use this product in accordance with the regulations.
Please read through the safety guideline, in case the meter is not used properly as
instructions, the protection provided may be weakened or lost.
Correct connection of ground wire: To avoid electric shock, please use the provided
cable to connect and make sure that the product is properly grounded before use.
Please notice the rated operating range. Please ensure that the mains supply does not
exceed 10% of rated operating range to prevent damage.
Use the correct power line: Only use the dedicated UNI-T power line to connect the
measuredpowersupplyandtheelectronicload,whichis toensurethatthereisno overheat
by short-circuit current, otherwise electric shock may occur.
Please notice the product marks before connecting. The instrument supports 2 kinds
of AC input method: 110V and 220V. Please check if the switch of load is match with the
input power source, and the fuse is correctly installed, or damage will occur.
Please do not operate in inflammable and explosive environment. Do not use or store
the meter in high temperature, high humidity, flammable, explosive and strong magnetic
field environments.
Never open the casing of the product. Only trained personnel can perform the
maintenance program. The instrument will not fully discharged after power off, which may
cause electric shock and injury.
Do not operate the product if you suspect it is faulty. Please contact UNI-T authorized
service personnel for inspection. Please disconnect the power supply and stop using.
Never use the instrument beyond the dedicated range of instruction. The provided
protection will be weaken or invalid.It is forbidden to use this product in life-supportsystem
or other devices with safety requirements.
Only trained personnel can perform the maintenance program. Any maintenance,
adjustment, or replacement of parts must be performed by UNI-T authorized maintenance
personnel.

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Safety Symbols
Direct Current
Alternating
Current
Both Direct and
Alternating Current
Three Phase
AC
Earth (Ground)
Terminal
Protective Conductor
Terminal
Signal
Grounding
Caution,
Possibility of
Electric Shock
Warning or Caution
Neutral Wire
or Central
Wire
Live Wire
On (Power)
Off (Power)
Backup Power
Ground Terminal for
Chassis
Environment-Friendly Use Period (EFUP)
This product contains certain hazardous
substances and can be used safely during its
environmental-friendly use period (EFUP) of 40
years, as shown in the symbol on the left. If the
specified time is exceeded, the product should
be recovered.
Waste Electrical and Electronic Equipment (WEEE) Instruction 2002/96/EC
Do not dispose the product and its accessories in trash bin.

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Table of Contents
Preface..................................................................................................................... 2
Copyright Information............................................................................................. 2
Warranty Service..................................................................................................... 2
Guarantee Limit....................................................................................................... 3
Safety Information................................................................................................... 3
Safety Symbols ....................................................................................................... 5
1. Product Description............................................................................................ 8
1.1 Product Series................................................................................................. 8
1.2 Front Panel...................................................................................................... 9
1.3 Rear Panel..................................................................................................... 11
2. Inspection and Installation ................................................................................. 9
2.1 Packing List................................................................................................... 12
2.2 Requirements of Power Supply...................................................................... 12
2.3 Operating Environment.................................................................................. 13
2.4 Cleaning ........................................................................................................ 13
2.5 Handle of Instrument...................................................................................... 13
3. Display Page of Measurement.......................................................................... 11
3.1 Power on and Run......................................................................................... 14
3.2 Introduction of Screen Display....................................................................... 15
3.2.1 Display of Measurement Interface........................................................... 15
3.2.2 Introduction of Status Bar........................................................................ 16
3.2.3 Running Indicator.................................................................................... 16
4. Measurement Setting........................................................................................ 14
4.1 Constant State Test Modes............................................................................ 17
4.1.1 Constant Current Test............................................................................. 17
4.1.2 Constant Voltage Test............................................................................. 18
4.1.3 Constant Resistance Test ....................................................................... 19
4.1.4 Constant Power Test............................................................................... 20
4.2 More Modes................................................................................................... 22
4.2.1 Dynamic Mode ........................................................................................ 23
4.2.2 List Mode................................................................................................. 24
4.2.3 Dual Mode............................................................................................... 28

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4.2.4 OCP/OPP Mode...................................................................................... 29
4.2.5 CR-LED Mode......................................................................................... 30
4.2.6 Battery Mode........................................................................................... 31
4.2.7 Load Effect.............................................................................................. 33
4.2.8 OVP Mode............................................................................................... 34
4.2.9 Short-Circuit Mode .................................................................................. 35
4.2.10 Time Mode............................................................................................ 36
4.3 Parameter Input and Loading Measurement.................................................. 37
4.3.1 Numeric Key............................................................................................ 37
4.3.2 Pulse Knob.............................................................................................. 38
4.3.3 Ripple Measurement............................................................................... 38
4.3.4 Input Control............................................................................................ 38
4.4 Trigger Method .............................................................................................. 38
4.5 Sense............................................................................................................ 39
4.6 Screenshot .................................................................................................... 39
4.7 Saving and Applying of Configuration............................................................ 39
5. System Configuration Page.............................................................................. 40
5.1 System Configuration..................................................................................... 40
5.1.1 Language................................................................................................ 42
5.1.2 Key Sound............................................................................................... 42
5.1.3 Date ........................................................................................................ 42
5.1.4 Warn Sound............................................................................................ 42
5.1.5 Time........................................................................................................ 42
5.1.6 DIM Display............................................................................................. 42
5.1.7 Initial Mode.............................................................................................. 42
5.1.8 Knob Active............................................................................................. 43
5.1.9 Communication Setting ........................................................................... 43
5.1.10 Restore Factory Setting......................................................................... 43
5.2 Parameter Setting.......................................................................................... 44
5.3 File ................................................................................................................ 47
5.4 Instrument Info............................................................................................... 47
5.5 Local/Remote ................................................................................................ 47
6. Communication Interface and Terminal........................................................... 48
7. Technical Specifications................................................................................... 51

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1. Product Description
Thank you for purchasing the Uni-Trend Programmable DC electronic load. This chapter
mainly covers the following:
Product Series
Front Panel
Rear Panel
1.1 Product Series
UTL8500 series DC electronic load contains 4 models: UTL8511, UTL8512, UTL8512B+
and UTL8513.
Models
Measurement Range
Voltage
Current
Power
UTL8511
0~150V
0~30A
0~150W
UTL8512
0~150V
0~30A
0~300W
UTL8512B+
0~500V
0~15A
0~300W
UTL8513
0~150V
0~120A
0~600W
UTL8500 series DC electronic load comes with 4.3-inch LCD screen, wide power range
and up to 0.1mV/0.1mAresolution. It supports multiple test modes: dynamic test, overload
test, auto test, list test, battery test and CR-LED test, etc. The instrument is great tools in
areas of electronic performance test, battery set test, power supply test, new energy test,
aerospace industries, high-power test, labs, R&D and production line, etc.
Equipped with standard RS232 interface and support more extension interfaces, UTL8500
series offer multiple-role solutions for your different design and testing requirements.
1.1.1 Features
Measurement Range: 150W/300W/600W,150V/500V,15A/30A/120A
Four Basic Test Modes: CC/CV/CR/CP
Function of Remote Current Monitoring and External Triggering
High Resolution of 0.1mV/0.1mA
Dynamic Voltage/Current Test with up to 10k Dynamic Frequency
Voltage/Current Sampling Rate: 40kHz
CR-LED Test, Power Source Rise/Decline Time Test
Protections of Over-Voltage/ Under-Voltage/ Over-Current/ Over-Power/ Overheat/
Anti- Reverse Connection

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The list mode comes with storage, and supports the saving and applying of the
external U disk and the upgrade of the U disk system.
Screenshot Function with List Storage & Recall
Equipped with Standard RS232 Interface and Support More Extension Interfaces
(USB or RS-485 Converted by RS-232)
Remote Voltage Compensation Input Function
Configured with Upper Computer Software for Remote Control and Monitoring
Ripple Sampling and Detection Function
Three Dual Tests: CR + CC, CV + CR, CV + CC
OCP/OPP/OVP Test and Load Effect Test
Intelligent Cooling Fan and Power-Down Memory Function
Independent Short-Circuit Test Function (Only for CC/CV/CR/CP Mode)
List Auto-Power-On Function and Over-Voltage Short Circuit
Pause Function in List Mode
1.2 Front Panel
Figure 1-2-1 Front Panel (UTL8512)
Table 1-2-1 Introduction of Front Panel
No.
Items
Description
①
Power Button: Press It to Power ON/OFF
②
USB Interface: The user can save the test data and screenshot to
U-disk. It can also be used in list test files storage/recalling and
system upgrade
③
Numeric Keyboard: It is used to enter numbers and decimal points.

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Delete the Input Values
④
Pulse Knob: It is used to adjust the parameters or move cursor in
the menu.
⑤
Direction Buttons: They are used to move cursor or adjust the
selected value.
⑥
F1-F6 Function Keys: They are used to perform the function
displayed on the screen.
⑦
Input Terminals: They are used to connect power source, please
do not inversely connect to prevent damage
Mode Shortcut Key: Press to enter setting interface to select CC,
CV, CR, CP and other modes.
System Configuration: It is used to set the system parameters,
operating parameters, file operations and view the instrument
information.
In order to avoid misoperation, the instrument adds keyboard lock
function. After pressing the lock key, other keys are disabled
except the ON key. When the key light is on, the keyboard has
been locked; long press for 1-2S to unlock.
Manual Trigger Button: Press Once to Operate a Manual Trigger
Load Input Control: ON/OFF
Esc Button: Exit or Return to Previous Menu
This button is used to confirm/modify the selected item or
parameters.

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1.3 Rear Panel
Figure 1-3-1 Rear Panel
Table 1-3-1 Introduction of Rear Panel
No.
Items
Description
①
AC 220/110V Socket
AC Power Input Socket (with Fuse)
②
ON/OFF Power Button
③
Trigger Signal Terminal
Please refer to part 6.2 for details.
④
AC 220/110V Transfer Switch
Voltage Scale Switch of AC Power Source
⑤
RS232 Interface
External Communication Interface to Realize the
Remote Control with the Load
⑥
Current Monitor Terminal
BNC Current Monitor Output Terminal
⑦
Sense (Remote Compensation)
Terminal
Remote Voltage Sampling for Electrical Load
⑧
Specification of Fuse
240V/0.25A 120V/0.5A
2. Inspection and Installation
This chapter mainly covers the following:
Packing List
Requirements of Power Supply
Operating Environment
Cleaning
Handle of Instrument

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2.1 Packing List
Before using the instrument, please first:
1. Check whether the appearance of the product is damaged, scratched or has other
defects;
2. Check whether the instrument accessories are missing according to the instrument
packing list.
If it is damagedor the accessories are missing, please contact Uni-Trend Instrument Sales
Department or the distributor immediately.
Items
Quantity
Remarks
Programmable DC
Electronic Load
1pc
The model is subject to the
actual order.
Power Cable
1pc
Standard Cable 250V/10A for
China
Spare Fuse
2pcs
240V/0.25A, Suitable for 10V
Voltage
User Manual
1pc
Users can download the
manuals from UNI-T’s official
website.
Factory Quality
Report
1pc
For UTL8512B+ and UTL8513
Certificate of
Conformity and
Warranty
1pc
2.2 Requirements of Power Supply
UTL8500 series can only be used in following conditions:
Parameters
Requirements
Voltage
AC 220/110 (±10%)V
Frequency
50/60Hz
Power
50W
Fuse
AC220V Input Voltage: 240V/0.25A
AC110V Input Voltage: 120V/0.5A
Three-core power cable is provided; please make sure that the ground wire of three-
phase socket is properly grounded before use.
The instrument comes with 220V/110V power transfer switch. Before connecting to

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the power supply, please check and ensure that the switch is in correct gear.
250V/0.25A (5x20mm) fuse is selected and installed for the instrument (220V) with a
spare fuse in the fuse case.
In addition, 2 spare fuses of 250V/0.5A are provided for input voltage of AC 110V.
When replacing the fuse, please remove the external power cable first, then open the
fuse slot under the power interface, take out the old fuse and replace it with a new one,
and install the fuse slot back after completion.
Warning: please do not use the damaged power cable to avoid danger. Use the
250V/0.5Afuse when 110VAC power is input.
2.3 Operating Environment
UTL8500 series can only be used in common-temperature and low-condensing zone. The
general environment requirements are listed as follows. During the on-load process, the
speed of the cooling fan will adjust based on the change of the cooling fin’s temperature.
Environment
Requirements
Operating Temperature
0°C~40°C
Operating Humidity
20%~80% (Non-Condensing)
Storage Temperature
-10°C~60°C
Altitude
≤2000m
Degree of Pollution
II
2.4 Cleaning
To avoid electric shock, please unplug the power cable before cleaning.
Clean the casing and the panel with a soft damp cloth, and make sure it is completely dry.
Warning: Do not use solvents like alcohol and gasoline.
Do not block the cooling outlet and clean the casing regularly (Unplug the power supply
before cleaning).
2.5 Handle of Instrument
The handle of UTL8500 is adjustable. Please hold the handle by both sides, pull outward,
and rotate it as needed, as shown in figures below.

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Figure 2-5-1 Original Handle Position Figure 2-5-2 Handle Position during
Measurement
Figure 2-5-3 Removing Position Figure 2-5-4 Lifting Position
3. Display Page of Measurement
This chapter mainly covers the following:
Power on and Run
Introduction of Screen Display
3.1 Power on and Run
The correct power-on and self-inspection processes of the electronic load are as
follows:
1. To power the electronic load on, please connect the power cable correctly, adjust the
ON/OFF switch on the rear panel to ON, and press the power button on the front panel.
At this time, the power button is green. The electronic load screen will display the
progress bar of current power-on and self-inspection, instrument information and other
parameters.
2. After initialization, the currentmeasuring status will be displayed on the screen. If start-
up mode has been set, the instrument will enter the preset measurementmode directly.
The completion of the correct power-on and self-check indicates that the electronic
load meets the factory standards, and the user can use it normally.
Turn off the power button on the front panel and adjust the ON/OFF switch on the rear
panel to OFF when the instrument is not in use.

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Note: Please read through the content of safety information in preface carefully before
using the load.
Warning:Pleasemakesurethat the power supplyvoltageisconsistentwith the supply
voltage before turning on the power, otherwise the instrument will be burnt out. Please
be sure to connect the main power plug to a power socket with ground protection. Do
not use a wiring board without ground protection.
3.2 Introduction of Screen Display
After entering into the test mode, the LCD screen will be divided into several areas to
display different information.
Figure 3-2 Interface of Measurement
3.2.1 Display of Measurement Interface
No.
Items
Description of Function
1
Mode
Current Measurement Mode or Status
2
Time
Current System Time
3
System Icon
Display the Status of U Disk, Remote Compensation,
Short-Circuit Test and Trigger Function
4
Parameters
Real-Time Voltage, Current and Power
5
Set Value
Mode Setting Information, Voltage and Current Value
6
Other Parameters
Real-Time Running Time, Other Processes and
Result Data
7
Mode Selection (Soft
Keyboard)
Select the Work Mode and Operate the
Corresponding Functions at the Bottom of the Screen

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3.2.2 Introduction of Status Bar
Status Description
Display Status
Description of Function
Measurement
Status
Status (Mode)
Current Measurement Status or Work Mode
Control Mode
Local/Remote
Current Operating Mode: Local/Remote
Screenshot Status
Waiting/OK/Fail
Saving the Picture/Saved Successful/Fail
Trigger Mode
Manual/External
Current Trigger Mode: Manual/External
Remote
Compensation
Sense
Sense Displays on the Screen: Remote
Compensation Has Been Turned on
USB Status
USB Storage Device Has Been Connected
System Time
0000.00.00
00:00
Current System Time: Year/Month/Date /Hour/
Minute
Alarm
Audio Alarm Is ON
Trigger Ready
Trig
Wait for Trigger, the Icon will Disappear after
Triggering
Start-Up Delay
Delay
Wait for Start-Up Delay, the Icon will Disappear
when Reaching the DelayTime, and then Start
up
Short-Circuit
Short
In Short-Circuit Test Mode
Pause Operation
Pause
In Pause Status
3.2.3 Running Indicator
UTL8500 series electronic load comes with running indicator on the ON button. In on-load
mode, the indicator will light up, indicating that the load is in a loaded status. Pressing the
ON button again can stop loading and the indicator will go out.
4. Measurement Setting
This chapter gives a detailed description of the mainfunctions of the electronic load so that
you can have a deeper understanding on the operation of the electronic load. It mainly
contains the following contents:
Constant State Test Modes (CC/CV/CR/CP)
More Modes (Dynamic, List, Dual, OCP/OPP, etc.)
Parameter Input and Loading Measurement
Trigger Method
Sense
Screenshot

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Saving andApplying of Configuration
4.1 Constant State Test Modes
There are four types of constant state test mode: constant current (CC), constant voltage
(CV), constant resistance (CR) and constant power (CP). In the initialization interface, the
user can select [Mode] by pressing the soft key at the bottom of the screen, and then press
[CC], [CV], [CR], [CP] to enter the corresponding mode.
The user can also press [More] to select more other modes, see Table 4-1.
Table 4-1 Introduction of Constant State Test Modes
Name
Description
CC Mode
The electronic load always consumes constant current regardless of the
input voltage.
CV Mode
The electronic load changes current consumption to keep the input
voltage as the set value.
CR Mode
The electronic load is equivalent to a resistance; it changes the input
current as the voltage changes.
CP Mode
The electronic load always consumes constant power; it reduces the
current when the voltage rises to remain constant power.
More Modes
There are many modes under this menu that can be selected by the
cursor to meet diverse testing requirements.
V,A, W
Parameters
Current Voltage, Current and Power Value
Status Bar
Current Mode, Time, Status and Other Parameters
In constant state test modes, set current/voltage/resistance/power and other parameters
will be displayed on the right side of screen. Input on-load parameters that need to be set
by numerickeyboard or knob. In on-load status,Time, Vpp, Ippand some other parameters
will be displayed at the bottom of the main screen.
4.1.1 Constant Current Test
In CC mode, the electronic load always consumes constant current regardless of the input
voltage.

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Figure 4-1-1-1 Setting Interface of CC Mode
Operation Steps:
1. In initial interface, select [Mode], and then press [CC] to enter the setting interface of
<Constant Current CC>.
2. Move the cursor to current setting by pulse knob, and press the Enter button to
change the current value (the value changes from yellow to white) by keyboard or pulse
knob. Press the Enter button again to confirm. At this time, the set current value
changes from white to yellow.
3. Other parameters can be modified in a similar way.
4. Press the ON button, the electronic load starts to load, and the indicator light below the
button lights up. If you need to stop the load, press the ON button again, and the
running indicator light goes out.
Figure 4-1-1-2 Relationship of Voltage and Current in CC Mode
4.1.2 Constant Voltage Test
In CV mode, the electronic load changes current consumption to keep the input voltage as
set value.
Constant Current Mode

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Figure 4-1-2-1 Setting Interface of CV Mode
Operation Steps:
1. In initial interface, select [Mode], and then press [CV] to enter the setting interface of
<Constant Voltage CV>.
2. Move the cursor to voltage setting by pulse knob, and press the Enter button to
change the voltage value (the value changes from yellow to white) by keyboard or
pulse knob. Press the Enter button again to confirm. At this time, the set voltage
value changes from white to yellow.
3. Other parameters can be modified in a similar way.
4. Press the ON button, the electronic load starts to load, and the indicator light below the
button lights up. If you need to stop the load, press the ON button again, and the
running indicator light goes out.
Figure 4-1-2-2 Relationship of Voltage and Current in CV Mode
4.1.3 Constant Resistance Test
In CR mode, the electronic load is equivalent to a resistance; it changes the input current
as the voltage changes to maintain a constant resistance value.
Constant Voltage Mode

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Figure 4-1-3-1 Setting Interface of CR Mode
Operation Steps:
1. In initial interface, select [Mode], and then press [CR] to enter the setting interface of
<Constant Resistance CR>.
2. Move the cursor to resistance setting by pulse knob, and press the Enter button
to change the resistance value (the value changes from yellow to white) by keyboard
or pulse knob. Press the Enter button again to confirm. At this time, the set
resistance value changes from white to yellow.
3. Other parameters can be modified in a similar way.
4. Press the ON button, the electronic load starts to load, and the indicator light below the
button lights up. If you need to stop the load, press the ON button again, and the
running indicator light goes out.
Figure 4-1-3-2 Relationship of Voltage and Current in CR Mode
4.1.4 Constant Power Test
In CP mode, the electronic load consumes constant power, and it will adjust the current
according to the voltage change to maintain the set power value.
Constant
Resistance Mode