I've had one GFCI in an apartment nuisance trip on me. Code here only requires they be in kitchens and bathrooms due to water hazards, and my patio outlet happened to be tacked onto the kitchen circuit. I was plugging in my electric smoker and at ~1500W on a 120V/15A line it would trip the GFCI whenever plugged in. I ran an extension cord to a circuit inside the apartment without a GFCI on it and it worked fine.

I have GFCI's installed throughout my house, and have some nuisance tripping with the ~15 year old one in the master bath. All the newer ones I've installed are fine.

I have read accounts of aquarists on online forums (reefcentral.com, for example) where GFCI's not only prevented electric shock/electrocution but also fire from water leaks that got into power strips (sodium makes a nice orange flame). Usual reports are blackened power strips and a tank full of dead fish when they get back from their weekend vacation, but at least their house didn't burn down.

 

Here in Australia they are mandatory on new property and have to be fitted to old property whenever they change owners.

I think they are a very worthwhile device.

BTW, isn't the name in the UK an RCD - Residual Current Device?

Mike.

 

I've also heard Aussies call them an RCD.

 

Here in Argentina they are mandatory for new residential buildings.

We don´t use GFI's integrated into an outlet but "general" GFI's integrated into the main circuit breaker panel.

The ussual configuration (the one that gives minimum cost and still passes the code) is one GFI as a main switch and several thermo-magnetic breakers (one for each circuit). Of course, when the GFI trips this gives you a "total blackout" - But a GFI costs much more than a circuit breaker.

It not only protects people against fatal shocks, it also protects appliances, wiring and the entire building against fire. When there is an overload and the wiring starts to melt or burn, if there is a ground wire along the power wiring there will be a ground leak and the GFI will trip.

I have seen many cases when a faulty appliance was "saved" by the GFI. For instance, a dishwasher with a stuck float switch that flooded itself and tripped the GFI. After drying it down and repairing the float switch it was OK, but if the flooded circuits had continued to operate until they tripped a 25A circuit breaker we would have a mess to clean up and repair.

I have installed GFI's in existing homes (at home and at some friend's), and it's a pain in the ...... In an old system, if there is a small leak somewere (and Murphy says of course there will be one), it will trip and keep tripping until you find ans repair the leak.

The most confusing case was at my parent's (a brand new building). We had the GFI tripping at random times, for no apparent reason . We eventually tracked it to the fridge: Sometimes when the fridge started the GFI tripped. We then pluged the fridge into a non-GFI outlet we had, and found that, sometimes, the GFI tripped when the fridge started

After some time we found that a fan's motor had a ground leak inside its windings, but it was almost at the neutral side, so it worked OK without tripping the GFI. But when the fridge started there was a voltage drop in the neutral wire, and the leak between neutral and ground was enough to trip the GFI (even when the fan was off, and with the fridge in a non-GFI otlet) We replaced the fan and we had no more false GFI tripping for years .

__________________
E Cerfoglio
Buenos Aires
Argentina

 

Thanks, all.