Residential wiring question.

[lckstckn2smknbrls]

This question is about shared neutrals.
My brother bought a house that needs to have GFCI protected outlets installed on each side of the kitchen sink. I pulled both outlet and found that there were so many wires in the boxes that a GFCI won't fit. Went to install a GFCI Arc fault breaker in the panel but found out the circuit for the outlets by the sink share the neutral with circuit for the rest of the outlets in the kitchen. So the GFCI Arc fault breaker trips with in 1 second, when the breaker for the rest of the kitchen outlets is off the GFCI Arc fault breaker works fine. Now there is a third circuit for the dishwasher that runs through the same conduit as the first 2 circuits.

Can I switch the shared neutral to be the dishwasher and the rest of the outlets not by the sink?

So to be clear there are 3 hot leads and 2 neutrals in one conduit from the breaker panel. The 2 circuits for the outlets share a neutral the circuit for the dishwasher has it own neutral.

 

[alldodge]

Many house's in the day were wired with 12/3 with ground. So it had 2 hot's, one common and one ground. First an ARC fault is not the same as a ground fault. ARC faults are used in areas where there could be an ARC, but they do not meet the requirement in a kitchen. The ARC fault can be used in conjunction with a GFCI but not in replacement of.

My Dad was a journeyman electrician I was not so take what I'm saying as that. You cannot use a GFCI breaker on 12/3 w/ground connection, it must be installed as outlets only. Wire the GFCI outlet as the load going into it, then out of it feed the remaining outlets. Running a dishwasher off a GFCI outlet will have issues, once the motor spins there is a fault and the GFCI trips.

 

[bruceb58]

My first question is why are you installing an arc fault breaker?

Also, if you can find the first outlet in the chain of outlets going to the kitchen sink area and install it in that box, you should be fine assuming that neutral is only feeding those outlets.

 

[lckstckn2smknbrls]

Many house's in the day were wired with 12/3 with ground. So it had 2 hot's, one common and one ground. First an ARC fault is not the same as a ground fault. ARC faults are used in areas where there could be an ARC, but they do not meet the requirement in a kitchen. The ARC fault can be used in conjunction with a GFCI but not in replacement of.

My Dad was a journeyman electrician I was not so take what I'm saying as that. You cannot use a GFCI breaker on 12/3 w/ground connection, it must be installed as outlets only. Wire the GFCI outlet as the load going into it, then out of it feed the remaining outlets. Running a dishwasher off a GFCI outlet will have issues, once the motor spins there is a fault and the GFCI trips.

In my area of Illinois we run the wires in EMT conduit. The breaker is an GFCI, Arc fault combo. Electric code now calls for GFCI, Arc fault breakers for kitchens and other areas. The new breakers are designed to sense motor start-ups and not trip. Arc fault breakers are also good if you have a worn extension cord Since the wires are in conduit the chance of an arc is minimal except that someone added under cabinet florescent lights using romex which is part of why there are so many wires and wirenuts in the boxes. I would have put a GFCI outlet as the first outlet if I could have. I worked for an electrical supply house for almost 20 years and am very comfortable in my ability to bend conduit, run wires, install outlets, switches, ceiling fans, lights ect ect.
The dishwasher is not on the GFCI, Arc fault breaker.

 

[lckstckn2smknbrls]

My first question is why are you installing an arc fault breaker?

Also, if you can find the first outlet in the chain of outlets going to the kitchen sink area and install it in that box, you should be fine assuming that neutral is only feeding those outlets.

The GFCI, Arc fault combo breaker is the new code so why not do the job right.
The physical size of the GFCI outlet wouldn't let it fit in to the box where it would be the first outlet in the run. That's why I went with the GFCI, Arc fault breaker.

 

[lckstckn2smknbrls]

I'm just not sure when it comes to shared neutrals.

 

[StarTed]

A single neutral can be used with a 240 volt load. At one time they used to separate the tops and bottoms of the outlets and have them on 2 breakers. That's not legal anymore. If it's a common trip breaker then 1 neutral is acceptable but not from 2 breakers. Technically 1 neutral will work from 2 breakers if they are on the 2 different hot legs. The current won't add, rather subtract, in that case but it's still not per code.

A GFI is essentially what the utility protection people use as part of the protection for substation transformers. They've used them for much longer than GFI or GFCI devices have been available and call them differential relays that trip the circuit if there is a difference between the currents being monitored. It's important to protect million dollar transformers.

I'm not a wireman so am not up on the current codes. I'm a journeyman meter electrician so my specialty is measurements.

 

[lckstckn2smknbrls]

A single neutral can be used with a 240 volt load. At one time they used to separate the tops and bottoms of the outlets and have them on 2 breakers. That's not legal anymore. If it's a common trip breaker then 1 neutral is acceptable but not from 2 breakers. Technically 1 neutral will work from 2 breakers if they are on the 2 different hot legs. The current won't add, rather subtract, in that case but it's still not per code.

A GFI is essentially what the utility protection people use as part of the protection for substation transformers. They've used them for much longer than GFI or GFCI devices have been available and call them differential relays that trip the circuit if there is a difference between the currents being monitored. It's important to protect million dollar transformers.

I'm not a wireman so am not up on the current codes. I'm a journeyman meter electrician so my specialty is measurements.

The 3 circuits/ breakers that I'm referring to are inline on one side of the panel, the 2 circuits that share the neutral are next to each other, separate hot legs. If I do switch the shared neutrals they will still be from separate hot legs.
As a last resort I can pull the meter, kill the panel then pulling all the old wires in the conduit out and pull new wires in. 3 hot and 3 neutrals.

 

[lckstckn2smknbrls]

And all the neutrals eventually join together at the neutral bus bar.

 

[batman99]

My 50 year old cottage's kitchen wiring is in the similar situation. re: 2 x hots + 1 x white (neutral) outlet is called a Split circuit. Common in old 80s kitchen area wiring and is now non-standard in today's minimum code. re: http://www.electrical-online.com/kit...acle-circuits/ Behind the coffee pot counter is a shared 15 Amp (shared with other outlets in the living room area). Definite over subscribed and under today's code as well. For my situation, I plan to remove shared 15 Amp circuit branch (from junction box to its kitchen outlet) and install a dedicated 20 Amp GFCI outlet (within its existing outlet box). And, I plan to remove the old standard 12-3 Split Circuit and install a new 20 Amp GFCI outlet to its existing outlet box as well. This is done via "pulling in new 12-2 / 20 Amp yellow" wiring runs via below access from basement removable ceiling tiles.

As mentioned above by other folks, it might be best to pull in new wiring runs and do each cable run properly. Might cost a few more dollars today but it could save a life (or fire) in the long run.....

 

[StarTed]

You have it figured right. Pull in all new wires and you'll be set as well as have more peace of mind.

The code in the US is by the National Fire Protection Association so it's based on safety from their perspective. I understand that European code is based on personnel protection so it differs. They don't ground like we do to my understanding.

By the way, a GFI or GFCI should work just fine without a ground but one is still required by code.

 

[bruceb58]

The GFCI, Arc fault combo breaker is the new code so why not do the job right.
The physical size of the GFCI outlet wouldn't let it fit in to the box where it would be the first outlet in the run. That's why I went with the GFCI, Arc fault breaker.

Are there only 2 outlets in the run or is there a 3rd or more? When you turn the power off to that circuit, how many outlets are now off?

Shared neutrals is strange. There is no way that can be code. Neutral is carrying the same current as the hot side.

 

[lckstckn2smknbrls]

Are there only 2 outlets in the run or is there a 3rd or more? When you turn the power off to that circuit, how many outlets are now off?

Shared neutrals is strange. There is no way that can be code. Neutral is carrying the same current as the hot side.

There are 5 outlets on that circuit, only 2 are close enough to the sink to need GFCI.

 

[bruceb58]

There are 5 outlets on that circuit, only 2 are close enough to the sink to need GFCI.

You can put it on an outlet that is not in the kitchen and have the loads of it be the ones next to the sink as long as the sink outlets are downstream form where you wire the outlet.

Look at a GFCI outlet. It has a line(input) and load(output) connections.

 

[Tim Frank]

Adding to Bruce's suggestion, You could go back almost to the panel box and do the split there. Add in a GFCI and you are done.

 

[lckstckn2smknbrls]

You can put it on an outlet that is not in the kitchen and have the loads of it be the ones next to the sink as long as the sink outlets are downstream form where you wire the outlet.

Look at a GFCI outlet. It has a line(input) and load(output) connections.

The first outlet in the run is one of the two by the sink and all the wires to the other outlets originate in this box. Which is why the box is too crowded to fit the GFCI outlet. In order to turn one of the other outlets into the first in the run I would have to pull the old wires out and pull the old wires plus a new wire and would be making the first box even more crowded. As it is it's hard to fit the duplex outlet into the box.

 

[lckstckn2smknbrls]

Adding to Bruce's suggestion, You could go back almost to the panel box and do the split there. Add in a GFCI and you are done.

The panel is in the basement about a 15' run to the first outlet box in the first floor kitchen. It's not a finished basement but there is drywall on the walls and ceiling. The conduit goes straight up into the ceiling and above the furnace, so there is not a good place to put the GFCI closer to the panel.

 

[bigdee]

You stated the problem was not enough room in the boxes to mount a GFCI. To make life simple way not bust out the old boxes and install deep boxes? They also make a "hook box" that is twice as wide in the back but still has an 2" opening that will fit without modifying your existing hole.

 

[gm280]

Code where I live states that any outside, sink area or bathroom areas have to have GFCI circuits. And so the GFCI in the master vanity area also covers the guest bathroom and outside receptacles as well. And even when I wired my shop, I installed GFCI on all the outside receptacles. And yes the county inspector did visually inspect and sign off on all the wiring as well. So the house has only one GFCI receptacle. I guess at the time they wired the house, wire was a lot cheaper then the GFCI receptacles were. Sound expensive to run copper wires all over the house and outside to be covered by one GFCI receptacle. Had I wired the house, I am certain I would have used multiple GFCI receptacles myself.

If your present boxes are too filled. Either remove them and install deeper versions or locate the common receptacle and replace with the GFCI. Then every things down the line is covered. JMHO!

 

[lckstckn2smknbrls]

You stated the problem was not enough room in the boxes to mount a GFCI. To make life simple way not bust out the old boxes and install deep boxes? They also make a "hook box" that is twice as wide in the back but still has an 2" opening that will fit without modifying your existing hole.

I would love to put in deeper boxes, the boxes are in an exterior wall with a tiled back splash.
There are 6 outlets not 5 I forgot about the one behind the stove.
I'm thinking I might be able to put the GFCI outlet on the far side of the stove. There are only 2 wires going to the outlet behind the stove and then on to the outlet on the far side of the stove. Then I would have to pull one new wire back to what was the first outlet.

Then my question would be will the GFCI outlet trip on a circuit with a shared neutral?
If it still will I'm back to switching the shared neutral or pulling all the wires out of the conduit and pulling all new wires with one more neutral.