1. Overload
Too many devices — the total current exceeds the rating. Solution: split the group or reduce the load. Check: sum the loads.
2. Short circuit
Damaged insulation, wrong connection — trips instantly. Solution: find and fix the damage, check the installation.
3. RCD/RCBO trips
Leakage: wet devices, damaged heater, bad neutral. Solution: check each device, measure leakage.
4. Bad contact
The terminal is loose — the breaker heats and trips. Solution: check the torque of the screws.
5. Inrush current
Powerful motors (fridge, pump) at start exceed the rating for a moment. Solution: curve C instead of B, or a higher rating.
6-7. Humidity and neutral
Humidity in the box — replace with IP44. A broken neutral causes surges — call the network organization.
How GorkyCAD helps
The scheme shows which devices are on the group — the overload is visible immediately.