Diagnostic knowledge
General, safety-first guidance written for this tool. It does not reproduce manufacturer service documentation.
Supply quality, protection devices and safe isolation practice.
Stop / escalate
Before any invasive check
- Isolate, lock off and prove dead with an approved voltage indicator.
- Only a qualified, competent person may open electrical enclosures.
- Never bypass, jumper or defeat a protection device to keep a system running.
Qualified technician
Nuisance tripping triage
- Record whether the trip happens on start, under load or randomly.
- Check for water ingress and rodent damage before insulation testing.
- Compare measured supply voltage and imbalance against the nameplate range.