Panasonic CU-4KS31NBU service manual Troubleshooting Before Calling for Service

8. TROUBLESHOOTING (BEFORE CALLING FOR SERVICE)

8-1. Precautions before Performing Inspection or Repair

Both the indoor unit and outdoor unit include electronic control circuits. Be sure to pay attention to the following before inspecting or repairing the outdoor-side electronic circuits.

High-capacity electrolytic capacitors are used inside the outdoor unit controller (inverter). They retain an electrical charge (charging voltage DC 311 V) even after the power is turned OFF, and some time is required for the charge to dissipate.

Be careful not to touch any electrified parts before the control circuit board Power Lamp (red) turns OFF.

If the outdoor control circuit board is normal, approximately 180 seconds will be required for the charge to dissipate. However, allow at least 30 minutes for the charge to dissipate if it is thought there might be trouble with the outdoor control circuit board.

For example, if the outdoor control circuit board fuse has blown, approximately 30 minutes will be required to discharge the high-capacity electrolytic capacitors.

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