:-? So the guys made up transformers 220 primary and 120 secondary, then hooked it up to a GFI. I asked why using X2 as the neutral? won't either X1 or X2 be equal if no ground established. Isn't the neutral supposed to have a gound bonded to the chassi, and earth to be at 0v?
establishing a neutral for transformer
- Thread starter j9DuBois
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LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Tradition. You're correct that it's really arbitrary with a 2-wire supply.
GFI bonded to chassi
GFI bonded to chassi
:-?ok, second part of same question.
The X2 of a control transformer is used as the neutral and this is hooked up to the GFI neutral side. The X2 neutral has not been bonded to ground. (which I think is wrong) What the consensus is that if X2 is bonded to ground it is tripping out the GFI, so what "they" have been doing is just going from the ground screw on the GFI to the chassi of the transformer, and just using the X2 as a neutral to the GFI without bonding it. SO how do you establish a ground with out tripping out the GFI or smoking the transformer?
GFI bonded to chassi
:-?ok, second part of same question.
The X2 of a control transformer is used as the neutral and this is hooked up to the GFI neutral side. The X2 neutral has not been bonded to ground. (which I think is wrong) What the consensus is that if X2 is bonded to ground it is tripping out the GFI, so what "they" have been doing is just going from the ground screw on the GFI to the chassi of the transformer, and just using the X2 as a neutral to the GFI without bonding it. SO how do you establish a ground with out tripping out the GFI or smoking the transformer?
brian john
Senior Member
- Location
- Leesburg, VA
It is really not an issue BUT it should be a grounded conductor
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
First
Transformers are isolating, if you don't have either lead bonded to the EGC/GEC, you will have no fault current path, no fault current path = no breakers trip, <<< code violation
2 if you do bond the X2 which is the common one most bond, then there must be 3 conductors from the transformer to the GFCI, one hot, one grounded conductor, and one EGC. these must terminate only on the line side of the GFCI receptacle, any load that has leakage between hot or neutral to ground will trip the GFCI.
I question as to how you are providing OCP for this GFCI receptacle?
As a hint a GFCI receptacle does not have OCP in it, just GFP @5 ma's
Hot to neutral will let through what ever current is on the supply side.
Transformers are isolating, if you don't have either lead bonded to the EGC/GEC, you will have no fault current path, no fault current path = no breakers trip, <<< code violation
2 if you do bond the X2 which is the common one most bond, then there must be 3 conductors from the transformer to the GFCI, one hot, one grounded conductor, and one EGC. these must terminate only on the line side of the GFCI receptacle, any load that has leakage between hot or neutral to ground will trip the GFCI.
I question as to how you are providing OCP for this GFCI receptacle?
As a hint a GFCI receptacle does not have OCP in it, just GFP @5 ma's
Hot to neutral will let through what ever current is on the supply side.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
Is the GFCI device single pole or 2-pole?
If the x2 is not bonded to the enclosure, then from 'hot' to 'egc' will not read on a meter,
the enclosure must also be grounded from its source. Are you by chance using an auto-
transfomer, that might be the problem.
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