Connecting old to new wires in receptacles and switches?

Question

Connecting old to new wires in receptacles and switches?

Answer 1

2 Wire Romex

Answer 2

The black wire is the hot facet of the road, or at least, it is supposed to be. The fact that it goes to the light swap helps that. That should go to the terminal of your receptacle that accepts the smaller blade. The white wire is the impartial. It should go to the terminal of the receptacle that accepts the broader blade. Seem for a third wire in the box. If the wiring is romex, there might be a third conductor. Or there maybe a bare or green wire in there someplace. That should be floor, and goes to the circular pin of the receptacle. It's completely feasible that there is no ground on an older residence, so after the whole lot is attached, do yourself a want and buy a receptacle tester from the ironmongery store. It'll have a number of lights on it, and will inform you whether there is a actual ground, and a few other wiring blunders. When you consider that this is in a kitchen, code might specify that you want a floor fault interrupter (GFI), if the outlet is a targeted distance from the sink. Which you could buy a GFI outlet, but it surely is not going to work until you have an specific ground in the box.

Answer 3

You need to find a ground source somewhere within the new wiring areas. A metal water pipe should be well grounded. You can also tap an existing ground such as a rod outside, or even drive a rod. Use green THHN 12 awg solid. You can't and shouldn't install grounded receptacles and wire them to isolated ground wire. Find a place/way to come out of one of those boxes that have new romex (for each circuit you affect) with thhn wire. Use a water pipe ground clamp for pipe, use an acorn clamp on a ground rod (1/2" for copper, 5/8" for galvanized steel) or you can also use a small pipe clamp for this purpose as long as it grips tight.



If it comes down to it (no other options) choose an outlet on an exterior wall and drill a small hole from the back of the box to the outside so you can pass a wire out and connect it to a ground rod even if you have to drive one down. 1 (10 foot) rod (galvanized or copper) is good for up to 100 amps.



Test voltage to ground when done. Compare to voltage-to-neutral. Should not be more than 1 volt difference. If you're ground is better than the neutral (higher voltage) then you need to improve the panel ground. (Drive a new rod for it within 6 feet and run number 6 solid copper from the rod to the neutral bar)



Also, some GFCI brands won't function (won't reset) when there is no ground connected to it. Good luck!

Answer 4

When you are mixing old wiring with new wiring there are several things you should know in order to have a safe and proper installation. First of all the splices can be made in the existing boxes as long as there is room for them. (There are codes and standards that indicate how many wires you can put in different types of electrical boxes. - One thing you don't want is to fill a box so full that you damage the wires when installing a device such as a switch or an outlet.) Never make a splice outside of an electrical box either. - This is dangerous and, should a problem ever occur with your splice, any arcing and sparking that might occur may not be contained and could ignite combustible materials in your walls or space where you put the splice. (See the Dependable Electric LLC link below for an example of the reason why.) Probably, the easiest thing to do is to protect the circuit by using a GFCI, (Ground Fault Circuit Interrupter). This can be accomplished by using a GFCI breaker or by using GFCI receptacles, (plugs), in the proper locations. (A GFCI has nothing to do with the ground; it will provide personal protection without it.) (See NEC, (National Electric Code), article 406.3(D)(3) and see the "Mike Holt" link below.)

One other important thing to know is that any wiring that does not have a proper ground should not be connected to the ground terminals on the devices. If there is a proper ground on any portion of the circuit then use it, but remember, JUST BECAUSE THERE IS A GROUND WIRE PRESENT DOESN'T MEAN IT IS A PROPER GROUND! A proper ground is a ground wire that goes all the way back to the power source, (i.e. the electrical panel) or one that is properly attached to the grounding electrode system. The reason for not connecting an "ungrounded" conductor to a grounding terminal on a device is because small amounts of voltages can be induced on those ungrounded wires, and, without being properly grounded, the voltage has nowhere to go; this can lead to a potential shock hazard.

There are cases where it really does pay to hire a professional; this should ensure a proper installation. I do suggest, if you are not confident, that you at least consult a proper electrician before doing the work.

Answer 5

This is one of those situations that highlights the can vs. should. CAN you hook them up and ignore the fact that there is no ground in part of the wiring; yes. SHOULD you do it; NO. If you're going to replace part of it, replace all of it. Doing half a job is how problems occur, and by problems I'm not just talking about things not quite working right, but fires and deaths. If you are pulling a permit, most inspectors won't let you get away with what you are wanting to do. If you're getting that far into a project, do it right the first time and you will make your life a whole lot easier in the long run.

There are provisions in the code that allow for these circumstances, however most municipalities will require you to bring up all the wiring to current code once you pass a certain amount of work. If you're re-wiring part of the house already, you could be forced to bring it all up if it is inspected.

Just because my truck will do 100 mph doesn't mean I should try it in a school zone.



Depending on how old the "old" wiring is, it may not be safe to still be using. If it has a cloth-like covering on it, or if it is older plastic and it is cracking or falling apart it all has to come out.



If you have any doubts contact your local inspector and/or a professional electrician to look at your situation and provide further guidance.

Answer 6

The National Electrical Code has provisions for box fill codes, but as a standard practice, this method is OK to use. Use an approved "wire nut" on your connections, not just twist and tape. Black to black and white to white and get them on the correct side of the outlet.



As far as the ground wire. I would strongly recommend against connecting a ground wire if a ground is not present in the box originally. The NEC give you 3 options to deal with this instance. 1, use an ungrounded outlet. An outlet that only has the 2 slots, not the 3rd "ground hole". 2 A GFI outlet can be used in this instance if you apply a sticker that states that the ground is not present. That sticker usually comes in the GFI box. And #3, get a ground wire to the box/outlet. The most difficult and expensive thing on the list, but the best.



You really need a qualified electrician to check for an existing ground. Just because you don't see one in the box does not mean a ground does not exist in the box. For example, BX, AC or MC type wiring can carry a ground.



Good luck

Answer 7

In many jurisdictions, it is no longer permissible to splice a new grounded circuit to an old ungrounded circuit. If you are trying to upgrade the electrical system, you should either do a complete rewire OR just run new circuits to locations where the are wanted without trying to integrate them into the old wiring. If you are unfamiliar with the code requirements, you should consult with an electrical inspector or a local electrician.



If you are trying to do the work without permits, you should be prepared for your insurance to deny any claims that arise from improper wiring techniques.

Answer 8

The black and white wires can be connected from old to new with the same color. BUT you need a ground. There are so many hazards if you have hanging wire that connects to nothing ESPECIALLY the ground wire.

Answer 9

Really the code has evolved to a point that it is hard for a homeowner (even with advice from yahoo answers) to be able to be aware of all the intricacies of the code (grounding, gfci, afci, 4 wire range circuits). But...



If you are not modifying the wire between the switchbox and the light you do not need to add a ground to that connection. All circuit conductors (black and white) must be spliced in a box, you can use the existing switch box, but you may not need to worry about the switches, often lights are wired hot from fixture to fixture, the switches will be connected to a "switch loop", which is just a hot from the ceiling and switchleg back up to the light.



If you are trying to extend a 2 wire circuit with 3 wire the National Electrical Code (issued by the National Fire Protection Association) Says:



250.130 Equipment Grounding Conductor Connections. ...



(C) 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



So to interpret those 4 points into normal english, you have to connect it to either (1)building steel, ground rod or water pipe within 5 feet of entering the building (2) the wire going to the first point, which elsewhere says need to be irreversible (crimped), (3)(4) Back to the ground point in the electrical panel. Nowhere does the code allow a separate ground rod not connected to the grounding electrode system.



If you are just replacing receptacles on a 2 wire circuit the code says:



NEC 406.3(D)(3) Where attachment to an equipment grounding conductor does not exist in the receptacle enclosure, the installation shall comply with (a),(b), or (c)

(a) A non-grounding-type receptacle(s) shall be permitted to be replaced with another non-grounding type receptalce(s)

(b) A non-grounding-type receptacle(s) shall be permitted to be replaced with a GFCI type of receptacle(s). The receptacles shall be marked "No Equipment Ground"....

(c) A non-grounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through a GFCI....shall be marked "GFCI Protected" and "No Equipment Ground"....