I need new kitchen circuits for a remodel. I don't want to run conduit outside of house for new circuits and I'm on the third floor so running new wire inside is a huge project. Conveniently, I have 2 unused wall heater circuits adjacent to the kitchen. These were 2 wire circuits using 12 guage wires, properly coming off of different phases in the main service panel. I know I have to disconnect one of the old "hot" wires from it's breaker and change it to neutral by connecting it to the neutral bus bar, but my question is, can I tap into the ground wires of an existing kitchen circuit to make these new circuits properly grounded ones that could also employ GFCI outlets if necessary? Thanks.

 

No, but you can add a ground wire if you run it to the breaker box. If these circuits are wired with metal conduit continuous to the breaker box the conduit can serve as your ground.

 

If these are for your two 20A small appliance circuits, you should be good to go. Just install a GFCI as the first receptacle on each and run the standard receptacles off the LOAD side of it. Paste one of the "No Equipment Ground" stickers that come in the box on each receptacle, including the GFCI. That should do it. No ground wire needed.

 

As I understand it you can not extend an ungrounded circuit but as Nashkat1 says you could probably add GFCI receptacles at the existing locations so long as you don't extend the circuit.

 

Ray raises an interesting question. I don't, in fact, know that it would be code compliant to add more new receptacles, and wire, to the LOAD side of a GFCI on an existing ungrounded circuit. I do know that it is code compliant to do that on an existing run of ungrounded cable, allowing the installation of three-slot receptacles to replace two-slot devices downstream from the GFCI, so I've always assumed that one could do the same with added devices. But I don't know. Maybe others here have that knowledge.

 

We need to know what kind of wiring method this is wired in first before we can give better info. IF it is cable, it likely has a re-identified white wire. IF it is conduit, a new wire could be pulled in.

As for the GFCI/ungrounded circuit issue, I would say yes, you can use a GFCI on the ungrounded circuit and wire all the other receptacles on the load side which is allowed by code. Receptacles should be marked "No equipment ground"

 

Little details. If the heater circuits used red and black conductor Romex type cable then you may not convert them into hot/neutral 120 volt circuits. You may not remark colored wires smaller than #6 gauge with white tape to be neutral.

If you run a separate ground wire back to the panel, it need not follow the exact path of the circuit Romex cable.

 

-I also agree that we need to know the wiring method.
-One question I have. What are the original colors of the conductors at the heater(s)? Example: Black and red. If so, then running a new circuit, or two new circuits is in order.
- Side note: You can extend a 2 wire branch circuit where the extension meets NEC 250.130C>>>> Nongrounding Receptacle Replacement or Branch Circuit Extensions. The equipment grounding conductor of a grounding-type receptacle or a branch-circuit extension shall be permitted to be connected to any of the following:
(1) Any accessible point on the grounding electrode system as described in 250.50
(2) Any accessible point on the grounding electrode conductor
(3) The equipment grounding terminal bar within the enclosure where the branch circuit for the receptacle or branch circuit originates
(4) For grounded systems, the grounded service conductor within the service equipment enclosure
(5) For ungrounded systems, the grounding terminal bar within the service equipment enclosure
-In addition—in the OP's case--If the circuits [the two heater circuits] meet the requirements for wiring receptacle and lighting loads of 120 volts.
Lost me here. Do you have two kitchens???



Edited to correct spelling, and add "lost me"

 

Upon "digging deeper" into these circuits I have discovered that one of them was run with 12/3 plus bare ground wire, romex. I hope to now use this as a shared-neutral 2 circuit path for the new kitchen circuits. I plan to dedicate one circuit each to the fridge and microwave respectively, such that there is no access to other appliances (one behind fridge, the other in a cabinet). Any caveats to this plan knowing, of course, that we need to put the two circuits on different phases at the service entrance? The other old heater circuit turns out to have been run with 14/2 plus ground romex with the white wire taped red. I hope to convert this to a new 120v dedicated lighting circuit for the kitchen since the current lighting circuit is shared with the vent hood, the gas range, small appliance countertop outlets and one adjacent bedroom outlet. BTW, the existing layout is good in some respects in that it has separate dedicated 20 amp circuits to the dishwasher and disposal as well as 3 small appliance 20 amp circuits (although, as mentioned, one of them also has all the lighting on it, including under cabinet).

 

Sounds good. Since the existing small appliance circuits are all dedicated, GFCI should work nicely - once you get that other stuff off one of the circuits.

I was wondering if something like that might be the case, and almost asked. 12/2 cable with two hot colors and no neutral exists, but it is a very rare, special order product.

 

Note for Canadian members: From what has been posted here in the past it is required in Canada on 240v circuits and is common.