KORAD KEL103/102 Programmable DC Electronic Load Tester

1. Introduction

The KORAD KEL103/102 is a high-performance programmable DC electronic load designed for testing power supplies, batteries, chargers, and other DC power sources. It offers multiple operating modes, precise control, and various protection features, making it an essential tool for R&D, production, and quality control applications. This manual provides detailed instructions for the safe and efficient operation of your KEL103/102 electronic load.

2. Product Overview

2.1 Front Panel

The front panel provides the primary interface for operating the electronic load. It includes a clear digital display for showing voltage, current, and power readings, a numeric keypad for direct input, function buttons for various modes and settings, and two rotary encoders for fine and coarse adjustments.

2.2 Rear Panel

The rear panel houses the power input, communication interfaces, and remote sensing terminals. Ensure all connections are secure before operation.

• AC INPUT: Power input connector.
• FUSE: Fuse holder for protection (e.g., 250V/5A).
• RS232: Serial communication port for PC control.
• USB: USB communication port for PC control.
• SENSE TRIG: Remote sense terminals for accurate voltage measurement directly at the load.
• LINE: Ethernet port for network connectivity (if applicable).

WARNING: To avoid electric shock, do not remove covers. Refer servicing to qualified personnel. Ensure proper grounding.

2.3 Included Accessories

The package typically includes:

• KORAD KEL103/102 Electronic Load Unit
• Power Cord
• RS232 Communication Cable
• USB Communication Cable
• Load Connection Cables (Red and Black)

3. Specifications

4. Setup

1. Unpacking: Carefully remove the electronic load and all accessories from the packaging. Inspect for any signs of damage.
2. Placement: Place the unit on a stable, level surface with adequate ventilation. Ensure the rear fan is not obstructed.
3. Power Connection: Connect the provided power cord to the AC INPUT on the rear panel and then to a suitable AC power outlet (110V-220V).
4. Load Connection: Connect the device under test (DUT) to the load terminals on the front panel using the provided load connection cables. Ensure correct polarity (+ to + and - to -). For remote sensing, connect the SENSE TRIG terminals to the DUT's output terminals.
5. Communication (Optional): For PC control, connect the RS232 or USB cable from the rear panel to your computer.

Safety Note: Always ensure the electronic load is OFF before connecting or disconnecting any power sources or loads. Connect the load to the source first, then turn on the electronic load using its power button to prevent current surges, especially in modes other than Constant Current (CC).

5. Operating Instructions

The KORAD KEL103/102 offers various operating modes and functions for comprehensive testing.

5.1 Basic Operation

1. Power On: After connecting the load to the source, press the POWER button on the front panel to turn on the unit.
2. Mode Selection: Use the dedicated buttons (CC, CV, CW, CR) to select the desired operating mode:
   • CC (Constant Current): Maintains a constant current draw regardless of voltage changes.
   • CV (Constant Voltage): Maintains a constant voltage across the load.
   • CW (Constant Power): Maintains a constant power dissipation.
   • CR (Constant Resistance): Maintains a constant resistance.
3. Parameter Adjustment: Use the numeric keypad for direct entry or the rotary encoders for fine-tuning the set parameters (e.g., current in CC mode, voltage in CV mode). The larger knob typically provides coarse adjustment, while the smaller knob provides fine adjustment.
4. Load ON/OFF: Press the "On/Off" button (often combined with Enter) to enable or disable the electronic load.

5.2 Advanced Features

• Memory Functions (M1-M5): Store and recall frequently used settings.
• LIST Mode: Program a sequence of load steps for automated testing.
• DYNAMIC Mode: Simulate dynamic load changes for transient response testing.
• BATTERY Test Mode: Specialized functions for battery discharge testing.
• OCP (Over Current Protection) Test: Test the overcurrent protection of a power source.
• Remote Control: Utilize RS232 or USB interfaces for PC-based control and data logging. Software for PC connectivity may be available online (e.g., Tenma 72-13210 CD program).

6. Maintenance

• Cleaning: Keep the unit clean and free from dust. Use a soft, dry cloth for cleaning. Do not use abrasive cleaners or solvents.
• Ventilation: Ensure the ventilation openings are clear of obstructions to prevent overheating.
• Fuse Replacement: If the unit does not power on, check the fuse on the rear panel. Replace it with a fuse of the same type and rating (e.g., 250V/5A).
• Storage: When not in use for extended periods, store the unit in a dry, dust-free environment.

7. Troubleshooting

• Unit does not power on:
  • Check the power cord connection.
  • Verify the power outlet is functional.
  • Check and replace the fuse if blown.
• Load does not turn ON:
  • Ensure the input source is connected and providing power.
  • Check for any error messages on the display.
  • Verify that the load ON/OFF button has been pressed.
• Inaccurate readings:
  • Ensure proper connection of load cables and remote sense wires (if used).
  • Check for loose connections.
  • Consider calibration if persistent inaccuracies are observed (refer to service manual or contact support).
• Overload/Protection triggered:
  • Reduce the set current/power to within the unit's specifications.
  • Check for short circuits in the load circuit.
  • Ensure adequate cooling and ventilation.

8. User Tips

• Hot Connection Safety: When connecting the load to a source that is already active ("hot"), be aware that in modes other than Constant Current (CC), there might be a significant current surge upon connection. It is strongly recommended to connect the load to the source first, then turn on the electronic load using its power button to ensure smooth operation and prevent surges.
• Measurement Accuracy: While highly accurate, expect minor deviations, typically in the last digit of the display, which is common for precision instruments.
• PC Connectivity: The device supports PC control via RS232 and USB. Generic software like the Tenma 72-13210 CD program (available online) can be used for remote operation and data logging.

9. Warranty and Support

This product is covered by a standard manufacturer's warranty against defects in materials and workmanship. For technical support, service, or warranty claims, please contact your vendor or the manufacturer directly. Please retain your proof of purchase for warranty validation.