E
elsparko
what about magic? its that time of yearI can't see it influencing the MCB. The arc carries the same current as the circuit (incomer, in this case) and behaves like a (poor) conductor, producing an equal field to a copper wire carrying the same current. Because of the way the gas ionises, the effective resistance fluctuates in ways that generate wideband noise, including at RF. But the energy radiated from the circuit picked up by the radio is a matter of milliwatts, and would not couple into the low resistance MCB heater or trip coil to any extent. To trip an MCB with an external field derived from a strictly limited current (there's a resistor in series with the arcing circuit) would require putting a substantial coil around it or carefully aligned next to it.
Does anyone think the MCB tripped magnetically, or thermally?