Overview
Error 63.1 is an Inverter Current Trip Fault, which can occur either due to a faulty Inverter PCB or an internal compressor issue.
The error typically appears during compressor start-up or operation when current flow exceeds the inverter protection threshold.
1. LED Diagnostic Reference (Inverter PCB)
| Condition | LED1 | LED2 | LED3 | LED4 | Indication |
|---|---|---|---|---|---|
| This time | 6 blinks | ON | ON | OFF | Current trip error occurred at start-up |
| Previously | 6 blinks | OFF | ON | OFF | Current trip error occurred during operation |
(Refer to LED indicators on top of the inverter PCB, near compressor terminals.)
2. Diagnostic Procedure
Step 1 – Observe LED Indicators
Power up the system and monitor the inverter PCB LEDs at the moment of compressor start-up.
Identify whether the 63.1 fault occurs immediately or after running for a short time.
If LEDs show the “This time” pattern → fault occurred during startup.
If LEDs show the “Previously” pattern → fault occurred during operation.
Step 2 – Measure Compressor Current
Using a true RMS clamp meter, measure current draw on the compressor power leads during start-up and ramp-up.
| Expected Observation | Diagnosis |
|---|---|
| Current draw rises rapidly and exceeds rated current | Compressor mechanical or electrical fault |
| Current stabilizes briefly before tripping | Inverter PCB failure or IGBT circuit fault |
Compare measured current to the compressor’s rated FLA (Full Load Amperage) on the nameplate or service label.
Step 3 – Additional Checks
Inspect power supply voltage balance across all input phases (for 3-phase units).
Check for loose or oxidized terminals at inverter or compressor connections.
Confirm fan operation to ensure adequate cooling of the inverter PCB during start-up.
If inverter board replacement is required, ensure matching board revision and firmware.
3. Corrective Action Summary
| Fault Source | Condition / Test Result | Action |
|---|---|---|
| Compressor | High or spiking current draw | Replace compressor |
| Inverter PCB | Normal current but repeated trip | Replace inverter PCB |
| Supply Power | Unbalanced or unstable voltage | Correct supply conditions |
4. Field Advisory
When diagnosing Error 63.1, always:
Check LED sequence immediately during fault occurrence (do not reset first).
Use a clamp meter to confirm compressor behavior before replacing PCBs.
Record LED pattern, current draw, and operating state for accurate fault tracing.