A protective device that trips is doing its job. When it trips repeatedly and no one can say why, the device is usually the only part of the system behaving correctly.
Start with the pattern, not the panel
The single most useful piece of information is the pattern: what time of day, what else was running, and how long after start-up. A fault that appears eighteen minutes into a shift has a different cause from one that appears the moment a particular motor starts.
We ask for a simple log — even a note on a whiteboard — for a week before touching anything.
The three usual suspects
- Insulation breakdown that only shows under load or warmth
- Earth leakage accumulating across many circuits, each one individually healthy
- A protective device selected for the wrong duty — the wrong curve for the actual inrush
Each of these looks identical from the front of the board and completely different once measured.
Measure, then decide
Insulation resistance, continuity, loop impedance and, where the pattern is thermal, a thermographic survey. Long-term logging captures what a five-minute test never will.
Only then do we recommend a repair. Replacing a device because it trips is not fault finding — it is a guess with an invoice attached.