Immediate safety action
Do not repeatedly reset the MCB to test the AC. Keep the AC off and call a qualified AC technician or electrician if the MCB trips again, if there is burning smell, visible water near wiring, sparks, shock sensation, or outdoor-unit wiring damage.
Safe observations to record
- Does the MCB trip immediately, after a few seconds, or after the compressor starts?
- Does it happen only in cooling mode, or even when the AC is switched on without cooling?
- Is there burning smell, water leakage, visible wire damage, or recent servicing?
- Does the outdoor unit start before the trip, or does the trip happen before any outdoor activity?
- Does any other appliance on the same circuit also fail or dim?
Possible fault directions
| Possible direction | Evidence that supports it | What still needs checking |
|---|---|---|
| Compressor or outdoor-unit fault | Trip occurs when outdoor unit attempts to start. | Technician inspection of compressor, capacitor, contactor, and wiring. |
| Short circuit or insulation problem | Immediate trip, burning smell, moisture, or visible wire damage. | Professional isolation and electrical testing. |
| Overload or weak protection device | Trip after load starts, shared circuit, or old MCB. | Electrician check of load, rating, wiring condition, and protection. |
What DeviceMitra AI would prepare
- Diagnosis report: possible fault categories ranked by reported evidence.
- Repair guidance: stop-use instructions, safe observations, and technician-only checks.
- Tools list: phone camera and flashlight for the user; multimeter, insulation testing, and AC tools for professionals.
- Missing evidence: trip timing, outdoor-unit behavior, water or smell, and circuit sharing.
Do not do these checks as a household user
- Do not open electrical covers or outdoor-unit panels.
- Do not bypass the MCB or use a higher-rated MCB to stop tripping.
- Do not touch wet wiring or metal parts if shock is suspected.
- Do not repeatedly restart the AC after a trip.