I wish I'd saved my little dog and pony
GFCI ppt
deck...
GFCIs/RCDs sense the relative balance of
current present in the load side's
neutral and
line. If there is an imbalance of >5 mA (USA/Canada, UK is higher), the device opens the
circuit. It is presumed that this
current is leaking via a connected device, appliance, or their
power cords/wiring devices and therefore presents a potential hazard to humans. If there is no leaking
current these devices will not open; they are not over-current protection devices. Anything that trips a
GFCI outlet or
breaker needs to be carefully inspected - device, appliance, cable, extension
cord,
power strip (esp the "surge protection" kind, as a sacrificed
MOV shunts
current to
ground, which will trip the
GFCI) - to find what is causing the problem. Note that
current leakage is cumulative within the
circuit, so a device with 2 mA leak, a
cord set with a 2 mA leak will not trip the
GFCI, but when you
plug in something else with a 2 mA leak, it trips.
Happy hunting!