i have an entire plant with gfci recpt's wired on shared nuetrals. we are tripping the ground faults. the wires come over (black,red,blue) with the lone white and a ground. split off and go in different directions. each circuit now picks up 2 or 3 boxes with 2 duplex recptales. one is a gfci duplex and the other is a standard duplex. each is wired line side for gfci and load out to the duplex recpt. next to it. some of the loads these outlets pick up are non linear and some are not. some power up small motors and some are just convenience outlets. my thoughts are if circuit A picks up a tape machine with a small motor on it and circuit B picks up an xray machine with a computer and touch screen in it and circuit C is picking up a label machine with a small servo motor in it and all this is going back on the same neutral could this trip the gfci's? none are daisy chained. all are spliced in the cieling boxes and brought down to the machines or outlets as 3 wire circuits. the neutrals are only spliced in the cieling box feeding the circuits. can not figure out why the gfci's are tripping. is it the shared neutral?
gfci on 208y with shared neutral
- Thread starter billk554
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MD84
Senior Member
- Location
- Stow, Ohio, USA
You can feed your GFCI with a MWBC but the receptacles downstream of the GFCI must have their own grounded conductor. Is this what you are doing? Could you draw a schematic?
Check out this thread http://forums.mikeholt.com/showthread.php?t=134001
Check out this thread http://forums.mikeholt.com/showthread.php?t=134001
JFletcher
Senior Member
- Location
- Williamsburg, VA
Your GFCI outlets will not know, care (or trip) to line side problems (eta: aside from gross problems which wont allow it to energize at all (reverse polarity, n/g reverse, etc.)). Your MWBC has to have a separate neutral to each GFCI. You said they arent daisy-chained, but also said standard duplex are fed from the load side of the GFCI, which, to me, is daisy-chained. Are you sure the GFCI receptacles are wired correctly with phase a/b/c/neutral from panel as line, and the duplex as load?
deta (double edit to add): if any of the phases is powering a 208/240V load downstream of the GFCI, it wont work either.
deta (double edit to add): if any of the phases is powering a 208/240V load downstream of the GFCI, it wont work either.
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kwired
Electron manager
- Location
- NE Nebraska
As said can you better describe or draw out how things are connected?
You can not share line and load side neutral to the downstream protected outlets you must have separate load side neutral to the downstream outlets.
You can not share line and load side neutral to the downstream protected outlets you must have separate load side neutral to the downstream outlets.
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