Red and black are hot. White is not. I have been trying to wire a GFCI & an outlet/switch combo. Tried numerous configurations and just bought a new GFCI because i suspected it. Nothing has worked.

Can I run black to “line” bronze screw and pig tailed white to silver “ line” screw? Then come off load side of GFCI and connect bronze load to black outlet terminal screw Run pig tailed white wire from silver GFCI load to silver terminal on outlet/ switch.then connect red hot line to brass terminal on switch and pig tail white to black upper switch terminal. Break off tab between black terminal screws. Seems too complicated. What am I doing wrong please

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    Does the outlet in the switch-outlet combo need to be GFCI protected? Is there a compelling reason you want the switch/lamp circuit GFCI protected? Is the breaker in the service panel a 2-pole (occupies two spaces) breaker or are they adjacent breakers? – Harper - Reinstate Monica Feb 23 '18 at 0:51
  • No neither the switch/lamp nor the outlet needs to be GFCI protected. I was just trying to get it installed that way. I suppose if we were to sell the house I guess it’d need to be code. Otherwise I was just adding an outlet. Breaker is single pole and controls both branches. So, if I wired it as described in the comment the switch outlet should work as should the two GFCI. Nothing coming off the load side. Black and neutral to line side. Switch brass wired to red hot and lower black terminal adjacent to outlet to neutral; leave the tab in. – Rick Waring Feb 23 '18 at 3:18
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    And you're sure it's not the middle of a quadplex, but actually a single pole breaker? One single-pole feeding both red and black?? Not illegal, just an odd waste of a wire. Could be a former MWBC someone downgraded. Does always-hot power go onward from here to anywhere else? – Harper - Reinstate Monica Feb 23 '18 at 3:32
  • I’m going to check but I think it may go to an outlet in the MBR on the same wall. I was cleaning house yesterday and noticed an outlet was dead despite power restored to problem area (with caps on wires of – Rick Waring Feb 23 '18 at 14:41
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    Took the sink light down. Standard two wires in, black white, ground. No other wires out. Checked outlet in same wall ,other side than bath. Standard two wires in to outlet two wires out to? These are push in connections so I’ll replace the outlet. So the red traveler is a mystery. – Rick Waring Feb 23 '18 at 17:13

What you have is a multi wire branch circuit. 2 hots sharing a neutral and ground. Ok it sounds right but the neutral for the red (switch leg) needs to come from the line side white. If the neutral comes from the GFCI load side every time you use the switch it will trip the GFCI. With that said gfci's can have problems with tripping on multi wire branch circuits. I have replaced gfci's that had failed with newer models and could not get the GFCI to hold there was no leakage verified with a Megger found an older model and it worked fine, I have seen this in the past and scratched my head because if the neutral is split prior to the GFCI it should work.

  • So, if I pigtail the neutral to black upper terminal on switch and to silver line terminal, attach red hot to brass terminal switch and black to brass line terminal at that point I should have two working GFCI outlets and a switched light and if I don’t break the tab between the blank switch/outlet terminals the outlet under the switch should work, just not be protected, right?. – Rick Waring Feb 23 '18 at 0:56
  • Correct if this is MWBC but is there a reason you really need 2 separate circuits worth of power? MWBCs are dangerous if you don't really know what you are doing (all due respect)... and I would not use them unless there is really call to. If you don't want to deal with it, just cap the red wire off with a wire nut, tape it down so it stays put, shove it into the back of the box, and use only the black/white. Much simpler. – Harper - Reinstate Monica Feb 23 '18 at 1:04
  • Will both the outlet and switch work with just black and white? – Rick Waring Feb 23 '18 at 3:37
  • I guess if I understood how the circuit in an outlet switch combo works I’d be home free. IF you connect hot to brass side of switch does that provide power to the outlet too, even if switch is off? If so, then I cap off the red as suggested, pigtail black to brass switch and brass line gfci. Then I pigtail white to silver switch, right lower black terminal (for outlet when switch is off) and to silver line gfci. Would that work? – Rick Waring Feb 24 '18 at 18:05

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