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Old 06-07-2010, 08:52 PM   #1
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Adding ground in old home

I am currently doing a bathroom renovation in my home and have some electrical questions that I hope I can get some help with.

First some background - the home is an old (1930's) house with an addition. The old portion of the house use 2-wire electrical, with no ground and an outside circuit breaker box. The addition has a separate circuit breaker box inside and has grounded outlets (though not all are properly attached to studs or anything, but don't get me started on how screwed up just about everything in this house is ). A large potion of the wiring is visible in the attic, with the old wiring being encased in the flexible metal conduit and the new wire being the standard yellow NM wire just ran across the attic.

My bathroom project removed a single switch that connected to a light and a GFCI outlet (when the switch was off, no power to the outlet ) which was connected to the old wiring with no ground. I have removed the light fixture, switch and outlet, and have reconnected the old wires (in the junction box directly over the bathroom) so I could turn the circuit back on, as my dining room light, hall light, and 2 outlets in the dining room were on the same circuit. (There was also another newer wire running to some other corner of the house that I am unsure of what it supplies).

My new bathroom plan involves a exhaust fan with a nightlight (4 wire connections plus ground), a vanity light, a GFCI outlet with switch, a 3-switch, a separate GFCI outlet, and a standard 3-prong outlet that will be used in the adjacent living room (currently has no grounded outlet, and would like to hook my entertainment center up in there ). My current wiring plan involves running power from the existing junction box to a new junction box, where I plan to tie main power to the separate GFCI outlet, standard outlet, and GFCI Switch/Outlet. The GFCI S/O will then load to the 3 switch, which will connect to the exhaust fan. So my wiring would look like:

12-2-G from old wiring to new junction box.
In new junction box, (3) 12-2-G spliced to wiring from old junction box:
2 black wires to black (line) screws on GFCI & Standard outlets
2 white wires to silver (line) screws on GFCI & Standard outlets
2 ground wires to ground screws on GFCI & Standard outlets

1 black wire to GFCI S/O black line screw
1 white wire to GFCI S/O silver line screw
From GFCI S/O:
1 black wire from black load screw to single black screw on 3-switch
1 white wire from silver load screw to white splice (running to white wire on fan/light).

1 white wire from black lead wire to white wire on vanity light
1 black wire from black lead wire to black wire on vanity light
From 3-switch
1 white wire from silver screw to white LIGHT wire on fan/light
1 black wire from silver screw to black FAN wire on fan/light
1 white wire from silver screw to yellow NIGHTLIGHT wire on fan/light

I have the ground screw on both the 3-switch and GFCI S/O spliced with the ground coming from the new junction, the ground from the fan/light, and the ground from the vanity. I have to 12-2-G wires ran to the fan to supply enough wires.

From what I have been told, seen around, led to believe, I can ground the entire bathroom by connecting the ground wire on the new wire (in the old junction box where the 12-2-G wire connects to the 2 wire existing electrical) to a separate wire ran either outside to a post in the ground or to a metal water pipe (the main galvanized drain pipe for the house is directly below the junction box) Is this correct? Does my wiring plan sound sound ( )? Or do I need to do something different?

Thanks in advance for any advice.
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Old 06-07-2010, 09:05 PM   #2
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Current code calls for the 20 amp bathroom circuit to either serve only receptacles in bathrooms or it can have other equipment like an exhaust fan and lighting if it only serves one bathroom.

You need to rethink your circuit.

Also your grounding ideas are not code compliant.
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
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Old 06-08-2010, 07:23 AM   #3
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Thanks for the answer, though some suggestions would be more helpful than just "your doing it wrong".

The circuit breaker box is in part of the addition, so I am not sure how easily I can run a new circuit but I will look.

If I can get to it I may run a new circuit for the dining room and living room as well, so the old circuit would no longer be used. If it is no longer used, can I just cap the wires, or is there something better to do? (Not sure if I would be able to remove the old circuit and all the wiring).

UPDATE: So I took a look at my circuit breaker box, and all of the white and ground wires are connected to the same screw on the neutral/ground bars. Should I do the same thing, or is this a problem that needs fixed? (Still not sure if I can run the wiring there yet, haven't checked yet).

Last edited by ChaosTheory; 06-08-2010 at 02:31 PM.
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Old 06-10-2010, 12:02 PM   #4
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I'm having a little trouble following your plan after the "new" junction box.
Can you re-write this and take each 12-2 leaving the j box and tell us your plan. Will you have power at the fan and then run switch legs or will you have power in the switch box that will feed the fan and night light?
You mentioned that everything is circuit breakers, even the old wiring. Is all the wiring from the old breaker box in flexible conduit (greenfield)? If so, the greenfield would provide a ground for the old wiring. You also said the new wiring is yellow NM. Yellow NM would be pretty new.
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Old 06-10-2010, 12:33 PM   #5
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Where are you located ?

Run a new 20a circuit to the bathroom
Old wires should be removed whenever possible if they will not be re-used
They need to be removed from the junction boxes, usually ends cut off so they can't be re-used

AFCI breaker protection required almost everywhere now - not in the bathroom

Neutrals & grounds are terminated on the same bars in the MAIN panel/1st disconnect

A ground can be run seperate back to the breaker panel
NOT to a water pipe

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Old 06-14-2010, 01:47 PM   #6
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Thanks for the replies. I do have a certified electrician coming to put in a couple new circuits, the way things are located and my novice level I figure it is better to pay a little money to have it done right than possible screw it up and/or fry myself

a7ecorsair -

The old wiring (as best as I can tell) comes from the circuit breaker in greenfield conduit to a junction. From there it splits, one line (in greenfield) going to the light for the adjacent dining room and the other (also in greenfield) going to a second junction box. This is the "old" box that is directly over the bathroom that I mentioned in my original post. Coming out of that box was a yellow NM wire running to the adjacent hall light, a NM wire running off to a far corner of the attic (not sure what it powers), a NM wire running to the (old) bathroom switch, and a NM wire running to the (old) bathroom vanity. Both old bathroom wires have been removed. And while the wiring is fairly new, nothing was grounded (don't recall if there were ground wires and they just capped them or if they weren't even there).

From the new circuit that will be installed I am splitting it to two wires.

One wire will run to and power a separate 20amp GFCI outlet.

The other runs to and powers a combination single GFCI outlet with a single switch. White and black wires connect to respective silver and black screws on the terminals marked as "Line". There are 2 black wires pre-installed for the switch that I have connected to the white and black wires that run to my vanity light.

I then connected a new black wire and new white wire to the "Load" terminals.

The new white wire connects to the two white (neutral) wires in the Fan housing.

The new black wire runs to a single receptacle (is that the correct term?) that contains 3 switches and has 1 black screw on the "Line" side and 3 black screws on the "Load" side. The black wire is connected to the black "line" screw.

From the 3 black "Load" screws I have a black wire ran to the red (hot) wire for the Fan light, a white wire connected to the black (hot) wire for the Fan, and a black wire connected to the yellow (hot) wire for the Fan nightlight. (One wire is white because I used two 12-2 wires to make my connections).

So the power from the new junction will split and power a standard GFCI receptacle and a combination GFCI/Switch receptacle. That recepticle will control the vanity light and supply power to a 3-switch receptacle that will control the combination fan/light/nightlight. Hope that makes things clearer

Scuba_Dave -

Located in KS.

New breaker is being installed soon

Old wires for the bathroom have been completly taken out and the old connections have been properly capped with wire nuts. (Previously they were just twisted together and taped up).

I plan on having the electrician install 2 new circuits, one will power my bathroom and the other will power my existing dining room power and a new outlet for my living room, and eventually a ceiling fan for the living room. By doing this, I am eliminating everything on the old circuit, so I was questioning - can I just cut the old wires as close (about 10 ft. from the wall the breaker box is located on) to the breaker box as possible? Or if I have my new living area junction box all ready would the electrician be able to quickly (thus cheaply ) remove the old circuit from the box and pull the old wire out that way?

Concerning the MAIN panel, as best as I can tell, the main power line enters the house and BOTH boxes are connected to it, so would they both be considered the main?
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Old 06-16-2010, 04:02 PM   #7
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All the ground wires in your house must end up back at the service panel, connected to the ground bus bar. Yes, your white neutral conductors are connected electricly to the same place, but that doesn't mean you can do the same outside the service panel. Same with the ground cable going to the ground rod or UFER, don't connect anything else to it.
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gfci switch/outlet , grounding , old electrical wiring , remodel

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