GFCI for 208V 3-phase
GFCI for 208V 3-phase
(OP)
I have a question about installing a GFCI on a machine which has a number of components, some of which run on 208V 3-phase and others on 120V single-phase. Is it possible/safe to install a GFCI at a single 208V 3-phase input to the machine and split the 120V loads off after the input using a single hot wire and the neutral? Would a GFCI made for 208V three-phase work? Thanks, in advance.






RE: GFCI for 208V 3-phase
RE: GFCI for 208V 3-phase
Anyone know of a GFCI that would work in this situation?
RE: GFCI for 208V 3-phase
RE: GFCI for 208V 3-phase
If you are just trying to detect ground faults, a molded case breaker with a solid-state trip unit including ground fault would do what you want, but you would need a neutral sensor in addition to phase sensor.
If you are trying to match the function of a standard single-phase GFCI breaker or receptacle, that is another matter. These operate at a much lower current level to prevent electrocution. Best bet for this would be to add GFCI receptacles or breakers for your single-phase loads downstream of the three-phase breaker.
RE: GFCI for 208V 3-phase
#1 - Startco SE-502 relay (startco.ca). This relay basically resistance grounds the neutral of a Y supply transformer and trips a under-voltage coil in a breaker. I have used one of these and tested it works with 6mA of ground current.
#2 - Bender LifeGuard GFCI (bender.org). This is a complete relay/breaker/transformer UL listed unit that provides the ground fault protection.
RE: GFCI for 208V 3-phase
RE: GFCI for 208V 3-phase
RE: GFCI for 208V 3-phase
Here's Schneider's offering:
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RE: GFCI for 208V 3-phase