Description

 

AC/DC Inverter Air Conditioner Motherboard Universal Board with Electronic Expansion Valve

Description:
- This board is suitable for replacement and repair of damaged AC or DC variable frequency air conditioning main control boards. Please choose the appropriate model based on the original machine condition when using it. The specific model is indicated on the side of the packaging box.

Check before Wiring:
- Unplug the U, V, and W wires from the compressor (mark them before unplugging to prevent reverse connection), measure the resistance between each pair with a multimeter in the resistance range, and ensure that the resistance is basically equal and there is no leakage to the compressor casing. If it is abnormal, please do not connect the board.

- External board power on experiment (This experiment is to determine whether the compressor can operate normally and whether it is DC or AC. If it can be determined that the compressor is normal and of the same type, this step can be ignored.).

- First, connect the two wires of the capacitor board to the external board, paying attention to connecting the red wire to C+ and the black wire to C-. Connecting them in the opposite direction will damage the board. Then fix the external board onto the original heat sink, and apply thermal conductive silicone on its contact surface to facilitate heat dissipation. Finally, connect the three wires on the compressor to the U, V, and W output terminals of the external board (be sure to plug them firmly), and do not plug them in the wrong direction.

- Check if the position of the dip switch is correct (factory set). If correct, connect the AC 220V mains power and start the power on experiment (use a card meter to detect the input current for the duration of power on). The board with an expansion valve will have a reset action of the expansion valve when power on. After hearing the relay close, wait for more than ten seconds for the compressor to start.

- After working for one minute, the current increases to a few amperes (usually 2-6A for hanging machines and 5-15A for cabinet machines), and the compressor runs smoothly. After the power is cut off, you can feel the steel pipe cool by hand, and the experiment is ended. Due to the need for air cooling to dissipate heat from the external fan board, it is not advisable to conduct a prolonged power test when the fan is not in operation to avoid burning out the module.

- If the compressor stops immediately after starting and the indicator light on the board flashes with an error, the control board will automatically restart. If it fails to start after repeated attempts, it is possible that the original machine is an AC compressor (DC compressor may also fail to start due to oil shortage, please pay attention to it). At this time, you can turn the dip switch "4" to AC mode and try again (generally, air conditioners produced after 2005 are mostly AC inverters, and those produced after 2010 are mostly DC inverters).

- During the power on process, closely observe the current. If the current suddenly increases by more than twice the normal value, immediately cut off the power, identify the cause, and try again to avoid unnecessary losses. Note: There is high voltage stored on the capacitor board. After power failure, wait until the indicator light is completely off before the power is basically discharged. Be careful of electric shock.

Package Included:
- 1 x Air Conditioner Motherboard