Tricks to install electrical outlet in existing run?

[edro]

This problem has come up numerous times through the years.

You have a pre-existing run of romex wire and you want to pop a new outlet into.
For example, in an unfinished basement or attic, you can see the romex, know the complete circuit and that it would be safe to add an outlet for future convenience.

Is it possible to do this without using 2 junction boxes?
The main issue is that once you cut the cable, there is not enough length to cut, strip and connect to the outlet.

Scenarios I have used or thought of:

1. Cut the cable, then pull the slack out of the run. This very rarely works as there is never enough slack (~3"+ on each end).

2. Don't cut the cable, but strip it and loop the bare conductors around the outlet terminals. This works if you have a little slack, but since you are not cutting the cable, you cannot pass each end through the conduit fitting/strain reliefs.

3. Use 2 junction boxes close together (or spread apart, or use 2 and install 2 outlets) or connected with connection fittings and add in some additional cable/wires to make up the distance lost going to the outlet terminals.

4. Go to either end of the cable run and disconnect it and feed it through the junction box, then replace the run you removed once the outlet is installed. The problem here is sometimes the ends are not easily accessible and may be nailed in place for a long distance.

If these are bad descriptions or too hard to visualize, I can MSPaint it up.

Maybe some of you professionals know a trick of the trade that I'm not seeing.

 

[CADsortaGUY]

1. Not likely to work but try before doing 3 or 4
2. Nope Nope Nope
3. Likely the easiest and would meet code if done correctly
4. Most expensive(except for $5) - I'd do #3 first.
5. Call an electrician.

 

[edro]

2. Nope Nope Nope

I've seen this done on older homes. Not sure what the method is called, but it seems to be a time saver for new construction with multiple outlets per circuit.
I can't find any images on google.
I don't think it would be against code or manufacturer (of outlet) recommendation.

 

[seepy83]

I'm running into a somewhat similar problem. We removed an old single-room Air Conditioner that was built in to the wall under a bedroom window. When we took out the unit, we found that the wiring for the regular electrical outlets originally ran through the wall where the Air Conditioner was. When the previous owner (or shoddy contractor) installed the A/C in the wall, they just cut the wire and spliced in some extra using wire nuts , and buried those splices in the wall (not even in a junction box).

I think the only way to fix this is going to be to cut out the sheetrock between the two outlets that are no longer connected, and replace the wire from outlet to outlet. I tried to fish cable through by pulling on the existing wire, but it's nailed/stapled in and I cant get it to budge.

House was built in the 70's, so i'm Dealing with some type of metal-clad cable...which I'm also not very familiar with. I guess it's grounded by the metal jacket...but I don't know how/if I can splice this in with romex or what I should do. May end up needing to call an electrician, but I hate spending that money.

 

[CADsortaGUY]

I've seen this done on older homes. Not sure what the method is called, but it seems to be a time saver for new construction with multiple outlets per circuit.
I can't find any images on google.
I don't think it would be against code or manufacturer (of outlet) recommendation.

I know of no code that allows for this type of connection. There are devices(outlets etc) which can be stab connected(mobile homes use them) but I have zero doubt what you describe would be against code. Code dictates all connections must be in an accessible box so it fails from the get go.

 

[CADsortaGUY]

I'm running into a somewhat similar problem. We removed an old single-room Air Conditioner that was built in to the wall under a bedroom window. When we took out the unit, we found that the wiring for the regular electrical outlets originally ran through the wall where the Air Conditioner was. When the previous owner (or shoddy contractor) installed the A/C in the wall, they just cut the wire and spliced in some extra using wire nuts , and buried those splices in the wall (not even in a junction box).

I think the only way to fix this is going to be to cut out the sheetrock between the two outlets that are no longer connected, and replace the wire from outlet to outlet. I tried to fish cable through by pulling on the existing wire, but it's nailed/stapled in and I cant get it to budge.

House was built in the 70's, so i'm Dealing with some type of metal-clad cable...which I'm also not very familiar with. I guess it's grounded by the metal jacket...but I don't know how/if I can splice this in with romex or what I should do. May end up needing to call an electrician, but I hate spending that money.

You would be correct - you'd have to replace wire back to previous connection point.

 

[Greenman]

I've seen this done on older homes. Not sure what the method is called, but it seems to be a time saver for new construction with multiple outlets per circuit.
I can't find any images on google.
I don't think it would be against code or manufacturer (of outlet) recommendation.

It will often work, it's safe if done properly, but code requires 6" of slack in the junction box for service. Just use two boxes and cut the romex.

 

[gorcorps]

Maybe I'm not understanding the situation properly... but why do you need two junction boxes? Couldn't you just cut the existing cable far enough away from where the outlet would be placed to give you enough slack on one end of the existing wire, then use a junction box on the "short side".

I feel like I'm missing something here, but you should only need one box methinks.

 

[edro]

Maybe I'm not understanding the situation properly... but why do you need two junction boxes? Couldn't you just cut the existing cable far enough away from where the outlet would be placed to give you enough slack on one end of the existing wire, then use a junction box on the "short side".

I feel like I'm missing something here, but you should only need one box methinks.

That is what I do, but it required 2 boxes.
1 for the outlet (also known as a junction box) and 1 for the junction only.

 

[gorcorps]

That is what I do, but it required 2 boxes.
1 for the outlet (also known as a junction box) and 1 for the junction only.

I gotcha. I don't have a whole lot of experience but I've only ever used the term junction box for boxes used solely for connections (no outlet or switches). It sounded like you were going to cut the wire right at the outlet, and then put a box on both sides of the outlet. :$

 

[Zorba]

Use 2 junction boxes. Be sure you look up code for the number of plugs/fixtures per circuit, generally 10. Though some jurisdictions change this, for example, many cities in Oklahoma only allow 2 per circuit in a garage.

For option number 2: If you actually had enough slack to do this, you should have enough slack to do it right with pigtails.

 

[Scarpozzi]

Just remember if you use a junction box, it has to be accessible from the wall. You can't get a handy box and cover it with sheetrock if there's a connection in there. Zorba is right about the number of devices per circuit. 8-10 is the limit, depending on the inspector. It's not an exact science, but it the number is going to be higher if you're running 12-2 instead of 14-2.

If you are installing new boxes, don't buy them from the big box stores like Lowes or Home Depot. Call up your local electrical supply houses and ask them for the largest boxes they have. They typically are higher capacity than what Lowes/HD sells allow more wires in them (read up on box fill). Most boxes will have X cu inches and often have a number on them to note how many wires you can have in the box.

You could possibly pull the old cable from one end and rerun half of the line to avoid a second junction, but if they used staples on the romex, which is code, you're screwed. Staples are supposed to be within 8" of plastic boxes. If I were going to run this, I'd get an "Old work" box and drill through the floor using a right angle drill....then run the line back to a recepticle through my crawlspace and not disturb the line in the wall. But every house is different. You may not have that as an option. I'm just not a fan of junctions. Otherwise, you could get a 2 gang box, cut the line and splice a pigtail there to the new recepticle if you have enough slack. Then cover one side with a blank and use the other.

 

[Zorba]

OP: Are you trying to install a new device well away from the existing devices? If not, you could just run a new line to one of the existing device's junction box and tap into the line there. Devices don't have to be connected in a daisy chain. This is what I always do if I want to add an outlet or light, since I don't want a random set of junction boxes in my attic.

Edit: As far as the limit on devices per circuit be sure to check your local codes as well as the NEC. Oklahoma limits the number of devices to 10 on 20-amp circuits (and bans the use of 15-amp circuits). I think NEC allows a few more on 20-amp circuits, though.

 

[edro]

I have already done this numerous times through my life, so it's not a certain scenario I am debating.
It was a general question on how others might do it.

I have generally used 2 junction boxes (1 with cover plate, 1 with outlet) connected together or some distance apart.

 

[stormkroe]

OP: Are you trying to install a new device well away from the existing devices? If not, you could just run a new line to one of the existing device's junction box and tap into the line there. Devices don't have to be connected in a daisy chain. This is what I always do if I want to add an outlet or light, since I don't want a random set of junction boxes in my attic.

Edit: As far as the limit on devices per circuit be sure to check your local codes as well as the NEC. Oklahoma limits the number of devices to 10 on 20-amp circuits (and bans the use of 15-amp circuits). I think NEC allows a few more on 20-amp circuits, though.

Wow, 15 amp circuits banned? That's crazy.
CEC allows breakers to be loaded at 80%, and outlets of unknown load are counted as 1 amp. So we can install 12 outlets on a 15 amp breaker. Pure lighting circuits don't have a quantity limit, it's simply based on calculated load.
I simply don't understand the aversion to 14awg wire and 15 amp circuits.

 

[waffleironhead]

OP: Are you trying to install a new device well away from the existing devices? If not, you could just run a new line to one of the existing device's junction box and tap into the line there. Devices don't have to be connected in a daisy chain. This is what I always do if I want to add an outlet or light, since I don't want a random set of junction boxes in my attic.

Edit: As far as the limit on devices per circuit be sure to check your local codes as well as the NEC. Oklahoma limits the number of devices to 10 on 20-amp circuits (and bans the use of 15-amp circuits). I think NEC allows a few more on 20-amp circuits, though.

Bans 15amp circuits? Where in the code amendments is this? Ok follows the nec, iirc. I'd be curious to read the amendment and the underlying reasoning.

 

[Greenman]

OP: Are you trying to install a new device well away from the existing devices? If not, you could just run a new line to one of the existing device's junction box and tap into the line there. Devices don't have to be connected in a daisy chain. This is what I always do if I want to add an outlet or light, since I don't want a random set of junction boxes in my attic.

Edit: As far as the limit on devices per circuit be sure to check your local codes as well as the NEC. Oklahoma limits the number of devices to 10 on 20-amp circuits (and bans the use of 15-amp circuits). I think NEC allows a few more on 20-amp circuits, though.

That's insane. You folks must have walk in sub panels.

 

[Zorba]

Bans 15amp circuits? Where in the code amendments is this? Ok follows the nec, iirc. I'd be curious to read the amendment and the underlying reasoning.

Oklahoma does use NEC, but it is amended at the state and local levels.

I guess I misspoke, sometimes the ban is on 15-amp circuits and other times on 14 AWG wire.

I am not 100% it is the entire state, but every city I've lived or looked at houses in has adopted the restriction. The state code board, though, does not list it as an amendment to the code. My Father in Law was an electrical contractor for 30 years in Oklahoma, when my wife and I lived in Ohio he helped me wire my basement and was like "WTH" when he saw the 14 AWG wiring and 15 amp breakers, he said he had never seen a house wired like that before.

Edmond: Para 16.16.100
Broken Arrow: Link
Stillwater: "The rating for other than individual branch circuits shall be: 20, 30, 40, and 50 amperes." Link

Sorry OKC's webpage sucks so I can't find the amendments.

Edit found OKC's: "210.19 (A)(4) is hereby amended by: Deleting the number “14” and inserting the number “12”." Link

That's insane. You folks must have walk in sub panels.

As for having a lot of sub-panels, I don't really follow you? We can have up to 10 outlets on a 20-amp circuit, I think most states limit 15 amp to 8-10 outlets. Some cities require something stupid, like Edmond requires bathroom blower heaters to have an independent circuit (so guess what, no heater blowers in Edmond ). And Tulsa only allows two outlets per circuit in a garage. But my Cincinnati house had more circuits than my Oklahoma houses, and my lights dimmed every time I ran my laser printer.

 

[waffleironhead]

Thanks for those links Zorba.

 

[Zorba]

Thanks for those links Zorba.

No problem. I really have no idea how that got started here, but seems very widespread and goes very far back in history.

 

[Greenman]

I wonder why they decided to go to 12 instead of 14 gauge wire? It just doesn't make any sense. Do people in Oklahoma have 20 amp alarm clocks or what?

 

[edro]

I wonder why they decided to go to 12 instead of 14 gauge wire? It just doesn't make any sense. Do people in Oklahoma have 20 amp alarm clocks or what?

Business. They have ties to the copper industry.

 

[Zorba]

I wonder why they decided to go to 12 instead of 14 gauge wire? It just doesn't make any sense. Do people in Oklahoma have 20 amp alarm clocks or what?

I am sure there was a reason at some point. Now it looks like the local contractor trades groups continue to push for the ban on 14 AWG. And since it is codified it just adds a little bit of cost to everyone, so not like some contractors get a benefit over another. And as previously discussed our building cost here is dirt cheap.

I know when I had a house with 14 AWG the lights would flicker anytime there a a large plug load (space heater or laser printer), you don't get that on 12 AWG.

While on the subject many localities here require 200 amp service for a house, where I think other places allow much less.

 

[who?]

The rules about how to safely wire a house should be in plaintext not code.

 

[DrPizza]

I wonder why they decided to go to 12 instead of 14 gauge wire? It just doesn't make any sense. Do people in Oklahoma have 20 amp alarm clocks or what?

While you wouldn't expect a larger appliance in a bedroom, for example, 19 below zero the other night. My wife and I put an oscillating 1500 watt heater in the bedroom. Normally it's cooler in the bedroom. It was see your breath until that heater was in there. That 1500 watt heater would have been enough to trip a 15 amp breaker if we had anything else on in the bedroom. (And my wife then ran a vacuum, which did trip the 20 amp breaker.) :roll: