KITCHEN WIRING – GFCI balanced circuit
toolbear
| Posted in Energy, Heating & Insulation on
Any way to make a double receptacle circuit with a shared neutral work if you use a GFCI breaker? I suspect not, but never tried it.
The ToolBear
“Never met a man who couldn’t teach me something.” Anon.
Replies
NO!
Frank DuVal
You can never make something foolproof because fools are so ingenious.
NO!
Rather figured that since the load on the neutral is (sez Richter & Swann) the difference between the loads on the hots, the GFIC might not see it that way.The ToolBear
"Never met a man who couldn't teach me something." Anon.
But you can make GFCI receptacles work.
Frank DuVal
You can never make something foolproof because fools are so ingenious.
Sure. A two-pole GFCI breaker will do just exactly what you want, if there's one available for your panel...and you're willing to pay big money.
Cliff
Sure. A two-pole GFCI breaker will do just exactly what you want, if there's one available for your panel...and you're willing to pay big money.
The panel is a 50 yr old Crouse Hinds with a tiny wiring gutter, 14 spaces, 2/3 of which are filled with half-height breakers and it will be history. I would love a 40/40 meter-main, but may wind up with something smaller. 2P/20A GFCI breakers in something modern should not be an issue.The ToolBear
"Never met a man who couldn't teach me something." Anon.
Well, O.K. then. You're outa luck. Or maybe you just upsell them on a new panel...even if not a heavy-up.
Good luck, Mr. Phelps...
Cliff
You can run three wire shared neutral from the panel to a box in which you put two GFCI receptacles. Pigtail the incoming neutral to the Line side of both of them. To protect other receptacles downstream, you have to keep the neutrals separate from the Load side of each GFCI onward. You have to be careful to identify which neutral belongs with which hot. (Easier done with Romex than conduit.) Swap them and both GFCI's will trip.
GFCI works by comparing the hot and neutral currents, and if they don't match, it figures electrons are going where they shouldn't, so it trips. It's just like one of those clamp-around ammeters that'll read the current in a hot or a neutral, but if you clamp it around both at once, they cancel out and it reads zero. The sensing coil inside the GFCI wraps around the load side hot and neutral.
-- J.S.
You can run three wire shared neutral from the panel to a box in which you put two GFCI receptacles.
Suspected the voltage comparison would sink that happy thought. Boss wants GF breakers, which is a good way to do it. We will have to run a pair of 12/2s and alternate boxes so every other box is on the same circuit. The ToolBear
"Never met a man who couldn't teach me something." Anon.
There's a current comparison between hot and neutral on the load side. But no voltage comparison that I know of in GFCI's. It might be that AFCI's look at voltage. They look for load variations around 400 Hz.
-- J.S.