KORAD KEL-103 KEL-102 DC Electronic Load User Manual

1. Introduction

The KEL series (150W~300W) are single-channel programmable DC electronic loads designed for middle and high-end applications. These versatile instruments offer multiple solutions to meet various customer needs. They facilitate online voltage measurements, adjustments, and simulated short-circuit tests using a simple keypad on the front panel. KEL series DC loads are ideal for static and dynamic testing of power supplies, batteries, DC-DC converters, and battery chargers, providing users with optimal testing solutions.

Main Features

• Highlight LED display
• 5-digit display, and accurate outputs
• Resolution of voltage and current: 0.1 mV / 0.1 mA
• Over-voltage Protection
• 100 groups of memories for fast recall
• Four working modes: CV/CC/CR/CP (Constant Voltage, Constant Current, Constant Resistance, Constant Power)
• Remote Compensation Function
• Battery Test Function
• Keyboard Lock
• Power off memory function
• Short-circuit function
• External Trigger Function
• Setting Function of Baud Rate

2. Safety Guidelines

Safety Symbols

The following safety symbols may appear in this manual or on the device:

• ! WARNING: Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
• ! DANGER High Voltage: Indicates the presence of high voltage that can cause electric shock.
• Earth (ground) Terminal: Indicates a protective earth ground connection.

General Safety Precautions

• Do not block or obstruct the cooling fan vent opening.
• Avoid severe impacts or rough handling that leads to damage.
• Do not discharge static electricity.
• Do not disassemble the unit unless you are qualified service personnel.

AC Input Safety

• Connect the protective grounding conductor of the AC power cord to an earth ground to avoid electrical shock.

Operation Environment

• Location: Indoor, no direct sunlight, dust-free, no conductive pollution.
• Relative Humidity: < 80%
• Altitude: < 2000m
• Temperature: 0-40°C

Storage Environment

• Location: Indoor
• Relative Humidity: < 70%
• Temperature: -10-70°C

3. Setup and Connections

AC Input and Fuse Information

The device supports AC input voltages of 110V/120V/220V/230V at 50/60 Hz. Ensure the correct voltage setting is selected on the rear panel before connecting to power.

To ensure fire protection, replace the fuse only with the specified type and rating. Always disconnect the power cord before fuse replacement. Confirm the cause of fuse blowout before replacing the fuse.

Included Accessories

The package includes the following cables for setup and operation:

• 2 x Test Cables
• 1 x USB Cable
• 1 x Power Cable (EU/AU/US type)
• 1 x RS232 Communication Cable

4. Front Panel Overview

The front panel features a clear LED display, control knobs, and a keypad for various operations and settings.

Keyboard Operation

• Esc: Cancel key, returns to the initial mode.
• M1-M5: Quickly recalls M1-M5 stored steady-state values.
• Recall: Recalls stored settings (e.g., Call+2).
• Shift: Accesses setting or storage functions (e.g., Shift+2 for storing content).
• Left-Rotating Key (←): Moves cursor to the position needing adjustment.
• 0-9: Numeric input keys.
• CC: Constant Current Mode Button.
• CV: Constant Voltage Mode Button.
• CW: Constant Power Mode Button.
• CR: Constant Resistance Mode Button.
• Enter: Confirmation Button.
• On/Off: Turns the load output On/Off.
• Up Arrow (▴): Adjusts number up or selects add.
• Down Arrow (▾): Adjusts number down or selects subtract.
• Knob: Adjusts the number or selects an item.

5. Rear Panel Overview

The rear panel provides connections for power input, remote sensing, and communication interfaces.

Connections

• SENSE Terminals: For remote voltage sensing.
• AC INPUT: Power input connector.
• FUSE: Fuse holder.
• RS232: Serial communication port.
• USB: USB communication port.
• LINE: Earth ground connection.

6. Operation

6.1 Setting the Maximum Value of Load

To improve accuracy, set low voltage (18V), low current (3A), and below them. For example, to set max current 3A, max voltage 18V, max power 100W, and max resistance 1000 ohms:

1. Press "Shift + CV" to operate.
2. Set the max current value and then press "ENTER".
3. Press "CV" to operate.
4. Set the max voltage value and then press "ENTER".
5. Press "CW" to operate.
6. Set the max power value and then press "ENTER".
7. Press "CR" to operate.
8. Set the max resistance value and then press "ENTER".
9. After setting, press "Esc" to exit.

6.2 Constant Current Operation Mode (CC)

In CC mode, the load maintains the set current regardless of input voltage changes.

1. Press the CC button on the keyboard.
2. Set the desired constant current using the keyboard.
3. Turn on the ON/OFF button to start the electronic load.

6.3 Constant Voltage Operation Mode (CV)

In CV mode, the load maintains the set voltage regardless of input current changes.

1. Press the CV button on the keyboard.
2. Set the desired constant voltage using the keyboard.
3. Turn on the ON/OFF button to start the electronic load.

6.4 Constant Resistance Operation Mode (CR)

In CR mode, the load maintains the set resistance regardless of input voltage and current changes.

1. Press the CR button on the keyboard.
2. Set the desired constant resistance using the keyboard.
3. Turn on the ON/OFF button to start the electronic load.

6.5 Constant Power Operation Mode (CW)

In CW mode, the load maintains the set power regardless of input voltage and current changes.

1. Press the CW button on the keyboard.
2. Set the desired constant power using the keyboard.
3. Turn on the ON/OFF button to start the electronic load.

6.6 Dynamic Test Function

This mode offers 6 setting functions: Dynamic CV, Dynamic CC, Dynamic CR, Dynamic CW, Dynamic Pulse, and Dynamic Flip. This mode has no storage function, so it must be set and run each time.

Dynamic CV, CR, & CW

Used for different duty cycle output of 2 different voltages at a certain frequency. For Dynamic CR and CW, change the setting voltage to resistance or power.

Dynamic CC

Used for different duty cycle output of 2 different currents at a certain frequency.

Dynamic Pulse

The load switches between two set currents upon receiving a trigger signal. The first setting current is active initially, then switches to the second upon trigger, maintains for a set time, and switches back to the first.

Dynamic Toggle

Similar to Dynamic Pulse, the load toggles between two set currents each time a trigger signal is received.

6.7 Sequential Operation Function

This function allows saving up to 7 groups of settings, with each group supporting up to 84 dynamic currents. The set currents can be toggled in sequence.

6.8 Battery Test Function

Allows setting up to 10 groups of battery test parameters. The test automatically turns off when any set condition (current, voltage, capacity, or time) is met.

6.9 OCP Test Function (Over Current Protection)

When the voltage reaches the VON value, the unit delays for a set time, then outputs current. The step value decreases progressively until it reaches the cutoff current, or the voltage exceeds the OCP setting. The test passes if the voltage is higher than the OCP voltage and the current is within the set maximum and minimum range.

6.10 OPP Test Function (Over Power Protection)

Similar to OCP, when the voltage reaches the VON value, the unit delays, then outputs power. The step value decreases until it reaches the cutoff power, or the voltage exceeds the OPP setting. The test passes if the voltage is higher than the OPP voltage and the power is within the set maximum and minimum range.

7. Advanced Functions

7.1 External Trigger Function

Press Shift+CR to switch the external trigger function. This allows triggering steady-state mode, dynamic test mode, sequence operation mode, and battery test mode via remote control. When the LED GRAP on the display lights up, it indicates external triggering is possible. This function includes memory.

7.2 Remote Compensation Function

Press Shift+CW to enable remote compensation. When active, the LED COMM will light up. This function does not have memory.

7.3 Keyboard Lock Function

Press Shift+← to lock the keyboard. When locked, only ON/OFF and Shift buttons are valid. In dynamic pulse and dynamic toggling modes, button 3 is also valid. This function does not have memory.

7.4 Baud Rate Setting Function

Manually modify the baud rate. For example, to change the baud rate from 57600 to 115200:

1. Press "Shift + 0" to enter the baud rate setting mode.
2. Rotate the knob or use the up/down buttons to adjust the display to 115200.
3. Press "ENTER" to confirm.

Please modify the baud rate only when there are no communications. This function has memory.

7.5 Buzzer ON/OFF Function

Press Shift+1 to toggle the buzzer on and off. This function has memory.

7.6 Communication with PC

Refer to the communication protocol for details on PC communication. When the keyboard is not locked, press Esc at any time to return to steady-state mode. To switch between modes, press Esc to enter steady-state mode first, then select the new mode.

8. Specifications

The specifications below are tested under conditions of temperature 25°C ±5°C and a warm-up period of 20 minutes.

Note: Specifications are subject to change without notice.

9. User Tips

No specific user tips were available in the provided customer reviews or Q&A. However, general best practices for using electronic loads include:

• Always ensure proper ventilation around the unit to prevent overheating.
• Verify the correct input voltage and fuse type before powering on.
• Familiarize yourself with the safety guidelines to prevent electric shock or damage to the device.
• Utilize the memory functions (M1-M5) for frequently used test parameters to save time.
• For precise measurements, use the remote sensing (SENSE) terminals if available and applicable to your setup.

10. Troubleshooting

No specific troubleshooting information was available in the provided data. For common issues, consider the following general steps:

• No Power: Check the power cable connection, AC input voltage setting, and the fuse on the rear panel. Replace the fuse if blown, ensuring it matches the specified type and rating.
• Incorrect Readings: Ensure test cables are securely connected. Verify that the correct operating mode (CC, CV, CR, CW) is selected and parameters are set accurately. Check for any external interference.
• Unit Not Responding: If the keyboard is locked, unlock it using Shift+←. If the unit is unresponsive, power cycle the device.
• Overload Protection Triggered: If OCP, OPP, OVP, or OTP is triggered, reduce the load, voltage, or current, or allow the unit to cool down. Review your test parameters against the device specifications.
• Communication Issues (USB/RS232): Verify cable connections. Check the baud rate settings on both the device and your PC. Ensure the correct drivers are installed on your computer.

If problems persist, consult the full user manual or contact customer support.

11. Warranty and Support

For detailed warranty information and technical support, please refer to the official documentation provided with your product. A comprehensive user manual in PDF format is available for download:

Download User Manual (PDF)

This PDF contains in-depth instructions, safety information, and detailed operational procedures not fully covered in this summary. For any further assistance, please contact your vendor or the manufacturer's support channels.