[Boatanchors] GFI

[rkerr]

In my experience, some old electronic equipment items with two-wire 
power cords have power line filter circuits that have 0.01 uF or 0.001 
uF capacitors connected from each of the two power line wires to chassis 
ground.  This effectively floats an ungrounded chassis at half the line 
voltage (via a relatively high impedance at 60 Hz..).  If the chassis is 
then connected to the power system ground, there will be a small 
unbalanced ground fault leakage current through the capacitor connected 
to the hot side of the power line to ground.  Sometimes this is enough 
to trip the GFI.

Bob
WB4TGG


Bob Kulow wrote:

>>Anyone ever run into problems using circuit breakers with 
>>built in Ground
>>Fault Interrupters (GFI) on circuits powering boat anchors?   
>>    
>>
>
><snip>
>
>I have had some problems with a Cutler-Hammer breaker/GFI combination unit.
>One fed a garage circuit and would trip whenever I used any brush-type motor
>on the circuit (power saw, router, et.).  Eventually I replaced it with a 
>straight breaker and installed a GFI receptacle in the garage.  That worked 
>Fine with no nuisance tripping.
>
>It's also a lot cheaper to install a separate breaker and GFI receptacle.
>
>73
>Bob WA2UEH
>
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