Changeover for backup generator

[SimonH2]

Well my little standby genny is only 3kVA - so nominally around 12A. I doubt it's going to trip even a B6 MCB in a hurry.
If overloaded, the engine revs drop as does the voltage.

 

[JohnW2]

Well my little standby genny is only 3kVA - so nominally around 12A. I doubt it's going to trip even a B6 MCB in a hurry. If overloaded, the engine revs drop as does the voltage.

Exactly my experience, too. As I just wrote:

I have no idea what sort of 'fault current' a small genny could supply during the first few tens of milliseconds, but, in my experience, any load appreciably above the 'rated' current will result in rapid reduction in output voltage followed by the engine stopping within a few seconds at most.

However, as I conceded there, it's possible that the genny might be capable of providing much higher currents (maybe high enough to magnetically trip an MCB) during the first (50Hz) cycle or two after a fault has appeared. I just don't know.

Kind Regards, John