This article examines the case of an inverter air conditioner that unexpectedly shuts off completely, even though it was operating normally. This issue includes the shutdown of the fan turbine and control panel, without displaying any error codes.
Inverter air conditioners regulate temperature by adjusting the compressor speed, eliminating the need for frequent on-off cycles. However, a complete shutdown, as described here, requires thorough diagnosis.
Diagnostic Process
1. Check the Voltage of the Electrical Network
- Use a multimeter set to AC voltage to measure the voltage supplied by the electrical network.
- If the voltage is abnormal, consider using a voltage stabilizer or inspect the electrical installations connected to the external network.
2. Check the Unit’s Power Consumption
- If the voltage is normal, measure the electrical current using a clamp meter set to AC current.
- Compare the measured value with the unit’s rated power consumption, indicated on the equipment’s label (Rated Load Amperage or RLA).
3. Evaluate the Compressor If Power Consumption is High
- If the measured current exceeds the normal value, the system should display an error code before shutting down. In this case:
- Disconnect the compressor from the electronic board and measure resistance between its pins.
- Ensure none of the measured values are infinite and that the resistances between the pins are equal.
- Verify that the resistance between each pin and the casing (ground) is infinite, using the megaohm resistance scale to rule out current leaks.
4. Inspect Switches If Power Consumption is Normal
- If power consumption is within the normal range, a faulty switch may be cutting power unexpectedly:
- Inspect the overload switch (audible click) located on top of the compressor.
- Disconnect the switch, bypass its connection, and test if the issue persists.
5. Replace the Shut-Off Switch on the Electronic Board
- If the problem continues, it may be related to the automatic shut-off switch on the interior electronic board:
- Remove the faulty switch by heating the solder points that hold it in place.
- Replace it with a new switch, ensuring proper installation.
- Restart the unit to confirm that the issue has been resolved.
