I'm pretty sure that a GFI senses an imbalance between the line current and the neutral current.You should not have any voltage across the neutral to ground. That is how a GFI circuit breaker senses a fault and shuts down the power. If you have voltage on the common leg or on the neutral/ground you have a circuit fault that needs to be addressed. Most GFI's sende in the range of Millivolts so the max leakage should be zero or nearly zero at all times.
Bob
It also senses if the current is going through the ground wire or ground, period, from the live, or any other way to ground, therefore upsetting the balance between neutral and live conductor.and none of it is going through either the neutral wire OR the ground wire.
Err - not exactly.You should not have any voltage across the neutral to ground. That is how a GFI circuit breaker senses a fault and shuts down the power. If you have voltage on the common leg or on the neutral/ground you have a circuit fault that needs to be addressed. Most GFI's sende in the range of Millivolts so the max leakage should be zero or nearly zero at all times.
Bob
2 x RMS voltage + 1000 for me at work.To look at it from the other side, at my job any equipement we produce at work is tested to withstand 500Vac between the PE and any other connection.
A bit misleading, if you don't have a ground referenced supply (grounded neutral) it won't work?A gfci doesn't need a ground conductor at all to operate properly.
Its all about line vs neutral current.. What goes in must come out.. if not "pop"
Then why is one of the normal techniques to provide protection in an old home that only has line-neutral wiring to replace the first recepticle in each chain with a GFI?A bit misleading, if you don't have a ground referenced supply (grounded neutral) it won't work?
Max.
Not misleading at all.. 100% correct. NO ground is needed at all for a GFCI to operate properly.A bit misleading, if you don't have a ground referenced supply (grounded neutral) it won't work?
Max.
It goes back to the transformer on the pole. Since it is now outside the home, you no longer care about it.Where is the return path?
if no grounded neutral?
The current has to go some where people!
Max.