Aircon Power Isolator Switch
The power isolator switch is the local switch used to isolate the aircon power supply for service and safety. If it is faulty, power to the unit can become unstable or fail.
What This Part Does
The power isolator switch provides a local way to isolate electrical supply to the aircon system.
It sits in the external power path and must maintain stable connection during normal use.
If it is faulty, the unit may lose power or show unstable startup behavior.
How You Would Notice
Some users report the unit does not power on, or power comes and goes. In other cases the indoor unit powers on but the outdoor unit does not start properly.
The symptom can overlap with breaker, terminal, or board faults.
From the user side, it may look like a general power issue.
- No power or unstable power to unit
- On-and-off startup behavior
- Symptom looks like breaker or wiring fault
It Might Not Be The Power Isolator Switch
Breaker trips, terminal connection faults, or other wiring issues can create the same symptom pattern.
Outdoor PCB or control faults can also make the outdoor unit appear dead even when supply is present.
We check the supply path and the control path separately before naming the isolator switch.
How We Check
We confirm the power-loss pattern and inspect the external supply path safely.
Then we check the isolator condition and compare findings with breaker and terminal behavior.
If supply is stable through the isolator, we continue with terminal or control-path diagnosis.
We recommend isolator replacement only when the switch is confirmed as the power-path fault.
What We Find And What Happens Next
Power-path complaints usually narrow down to isolator issue, breaker issue, terminal fault, or a control fault after supply checks pass.
| Finding | Next Step |
|---|---|
| Isolator switch faulty | Replace isolator and retest power path |
| Breaker issue pattern | Check breaker and supply path |
| Terminal or wiring fault | Repair connection path and retest |
| Power path normal | Continue diagnosis on outdoor control path |
About The Repair
Isolator-switch replacement is a power-path safety repair. The main point is confirming the switch fault before replacement.
Replacing the isolator will not fix breaker or outdoor PCB faults.
We confirm the supply path after repair before sign-off.
After Replacement
Power supply to the unit should be stable if the isolator was the main fault.
If startup issues remain, another power-path or control-path fault may still be present.
We retest power and startup behavior before closing the job.
When We Tell You To Wait
If the issue happened once and power is stable now, short-term monitoring may be reasonable while you record the pattern.
If power keeps dropping, or there is burning smell or heat signs, do not delay checks.
We will tell you when the issue is likely a power-path fault versus a separate control problem.