[photon_rancher]

Over 100nF of unbalanced Y-caps is needed at 60Hz/120V to see 5mA gnd current. That would be a big Y capacitor (2.2n or lower is common) and they’re usually used in a balanced configuration which would reduce it further. If a Y capacitor fails on one leg, you have a problem. If a Y capacitor fails is only present on one leg, you have a problem.

And if it’s resistive leakage, that’s almost a watt of dissipation - also huge and probably a short in a cable and potentially a fire risk.

5mA is a massive threshold for well designed devices

[Workaccount2]

It would be fast transients that are in the kHz to MHz and over 120V. Thats why I wonder about the sensitivity of the GCFI. Can it tolerate 5mA for 50ns?

[atoav]

It should, typically trip times should be in the single digit miliseconds range (the idea is to stop within half of a 60/50Hz cycle).