PC08 Error Code in Air Conditioning

The PC08 error code in air conditioning systems is generally associated with an excess of current. Below are the recommended steps to solve this error, starting with the easiest procedures and progressing to more complex ones:

---

Steps to Resolve PC08 Error

1. Disconnect the unit from the electrical supply:
   • Wait for several minutes before reconnecting it.
2. Reconnect the unit and check if the error disappears.
3. Check the cleanliness of the outdoor unit (condenser):
   • Make sure the fins and coils are free of dirt and obstructions.
4. Verify the operation of the outdoor unit fan:
   • Ensure it is turning correctly and that there is sufficient airflow, allowing hot air to escape easily.
5. Measure the power supply voltage with a multimeter:
   • Check that the voltage from the electrical grid is normal.
6. Check the refrigerant charge:
   • If the unit was recently recharged, there could be an excess of refrigerant.
   • For refrigerants like R410A and R32, the pressure should be around 120 psi.
7. Inspect the electrical connections of the compressor:
   • Ensure there are no loose connections or false contacts.
8. Diagnose the compressor:
   • Disconnect the compressor and measure the electrical resistance between the connector pins with a multimeter set to ohms.
   • The values between pin pairs should be equal, and it should never show infinite resistance.
   • Also, measure the resistance between each pin and the compressor’s casing using the megaohms scale.
   • The resistance should be infinite, indicating no ground leakage.

---

Inspection of the Electronic Control

9. Check the indicator LEDs on the control board:
   • If the LEDs light up or flash, it indicates that the board is generating DC voltage.
   • In this case, focus on the IPM (Intelligent Power Module) circuit.
   • If no LEDs are on, focus on the PFC (Power Factor Correction) circuit.
10. Inspect the PFC circuit:
    • Ensure that DC voltage is present at the output of the rectifier bridge.
    • For units powered by 110 V AC, the voltage should be around 150 V DC.
    • For 220 V AC units, the voltage should be around 300 V DC.
11. Check the PFC circuit coil or reactor:
    • Without powering the board, check for electrical continuity between the input and output of the coil.
12. Inspect PFC circuit components:
    • Check the resistance values, the condition of the diode, and the electrical continuity of the board’s traces.
    • Also, test the capacitors with a capacitance meter.
13. Examine the IGBT transistor in the PFC circuit:
    • Check for any failures or short circuits.

---

Testing the IPM Electronic Module

14. Disconnect the unit before performing any tests:
    • Ensure that capacitors are discharged using a multimeter set to DC voltage.
15. Locate the IPM circuit:
    • The IPM circuit is covered by heat sinks, and its pins are connected via three independent traces and an electrical connector to the compressor’s three pins.
16. Test the internal diodes of the IPM circuit:
    • Set the multimeter to the diode test mode.
    • Test the first three diodes:
      • Place the black probe of the multimeter on the positive input of the IPM circuit.
      • With the red probe, measure the points U, V, and W.
      • The activation voltage for each measurement should be around 0.45 V.
    • Test the last three diodes:
      • Place the red probe of the multimeter on the negative input of the IPM circuit.
      • With the black probe, measure the points U, V, and W.
      • The activation voltage for these should be similar to the previous ones.