6 Sep
2014
6 Sep
'14
12:43 p.m.
At any rate, I don't think you need to worry about
90 microamps leakage.
Most US GFCIs don't trip until the leakage current is somewhere around
6 ma--or about 60 times what you're seeing.
I am not sure what the legally allowable leakage current (to pass a PAT
test) is in the UK, but personally, if the leakage resistance is gettign
close ot 1M Ohm I want ot know the reason why.
It may be OK, it may be part od the desing. Or it may be comething
breaking down which can only get worse.
An example. I havbe an HP13215 PSU here (for the 7900 disk drive) which
shows just over 1M of leakage form the mains input to chassis.
Disconnecvting wires shows that the transformer is fine (getting on for
100M OHms, the leak is i nthe mains fitler can. This is certainly a DC
leak, and even shows up usign a noraml DMM.
I've not had a chance to invetigate further. If this is a discharge
resistor in the mains filter (they were nto uncommon at opne time) to
discharge the fitler caps and prevent shock,s then fine. If it;s a
capacitor breakign down then not fine. I need to investigate before I use
the PSU seriously.
-tony