Tag Info

New answers tagged


Whether it's a bulb blowing or an appliance failing in our house, the main 80A / 30mA RCD breaker always trips but the Type B MCBs for the individual circuits (e.g. lights, sockets, cooker, shower, immersion heater etc.) never do. Surely that indicates that the panel is incorrectly wired or that the main breaker is too sensitive.


In a short circuit condition, there are very high currents. As previously stated, the initial over drawing heats a bi-metallic strip that acts as a thermal cutout for excessive loads. The second is a small coil inside the breaker that when exposed to high currents (short circuit) acts exactly like an electromagnet and pulls the breaker open immediately. ...

Top 50 recent answers are included