[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Ground fault circuit interrupter (GFCI or GFI) (was Re:T8 electronic ballast wiring)

Wayne Jones wrote:
Making your own fixture has some safety pitfalls. Make sure the ballast and
reflector are grounded and make doubly sure that the sockets cannot fall out
and plunge a lit tube into your tank. I would also want to use a GFCI outlet
for the power supply.

I spoke with an electrical engineer about this and he mentioned that the GFCI alone may not protect you from electrocution.

Imagine a simple situation with just an aquarium filled with water and a heater with a broken glass tube.  The broken heater would cause a hazardous condition in the water.  However, since the glass of the aquarium makes an excellent insulator, the GFCI may not detect a difference between the current flowing in each conductor and therefore wouldn't trip.  But if you then stuck your hand in the water, some of the current would now have a path by which it could flow to ground.  The GFCI would then trip after detecting the resulting difference in current flow between the two conductors.

A ground probe like the kind sold for saltwater aquariums would also provide a path to ground and would therefore cause the GFCI to trip as soon as the water contacted the electrical parts inside the heater.

Wade Shimoda