Will GFCI work with items without equipment ground
I know it's probably a dumb question but my wife's hair dryer is old and has no equipment ground. Wanted to be sure she is still protected if it should be dropped into water or otherwise shorted.
Forum Discussion
while a GFCI is designed to protect you in the case of getting across hot and neutral it is NOT guaranteed to protect you. If you are well insulated from any ground path (in the house with rubber soled insulated shoes) and get across the hot and neutral ALL the current flows through you via the hot and neutral and none through any ground path. hence no GFCI trip.
Of course this is not the typical fault case but it can exist. As an example try using a outlet tester with a GFCI test button in a typical trailer hooked to a typical generator with unbonded ground and neutral. in most cases it will NOT trip any GFCI outlets. The reason is that the neutral and ground in the trailer are not bonded, nor are they bonded at the generator, and the trailer sits on rubber tires generator sits outside with plastic high insulation resistance between the neutral or ground and earth grounde hence limited or no ground path. same as if you got across hot and neutral in the trailer.
A outlet based GFCI provide NO overcurrent protection just current imbalance protection. It relies on an upstream CB for overecurrent protection, a Circuit breaker GFCI will provide overcurrent protection and current imbalance protection.
Now a GFCI will also detect and trip on one other fault. A downstream ground/neutral bond. By code ground and neutral are not to be connected together anywhere but the main breaker panel. so if ground and neutral are bonded downstream of the GFCI it will detect this short and will trip. This will occur even if there is no current flowing in the circuit.
Of course this is not the typical fault case but it can exist. As an example try using a outlet tester with a GFCI test button in a typical trailer hooked to a typical generator with unbonded ground and neutral. in most cases it will NOT trip any GFCI outlets. The reason is that the neutral and ground in the trailer are not bonded, nor are they bonded at the generator, and the trailer sits on rubber tires generator sits outside with plastic high insulation resistance between the neutral or ground and earth grounde hence limited or no ground path. same as if you got across hot and neutral in the trailer.
A outlet based GFCI provide NO overcurrent protection just current imbalance protection. It relies on an upstream CB for overecurrent protection, a Circuit breaker GFCI will provide overcurrent protection and current imbalance protection.
Now a GFCI will also detect and trip on one other fault. A downstream ground/neutral bond. By code ground and neutral are not to be connected together anywhere but the main breaker panel. so if ground and neutral are bonded downstream of the GFCI it will detect this short and will trip. This will occur even if there is no current flowing in the circuit.
