testing help

[bonjovi]

can anyone tell me why testing a rcd should not be done before earth loop test many thanks

 

[ezzzekiel]

because youre relying on an earth fault loop path existing

 

[dazza69]

Hi bonjovi, the RCD requires a good earth fault loop path to operate correctly, so if you test the RCD first and the earth fault loop impedance is to high and untested at that point your initial results would show that you have a faulty RCD when there is possibly nothing wrong with the unit. Always do the Ze first.

 

[bonjovi]

many thanks wel discribed and understood