Electrical question

[Lumber_Jack]

So I'm looking to add an electrical outlet in my basement/garage. There are only two there now.

The ceiling is unfinished as are the walls with the exception of the area underneath the stairway. This is the area I want to add the outlet. Running across the joist above are 3, 12-2 Romex cables. My thought was splicing a junction into one of the cables and dropping the outlet from that. I don't see a need to run a new cable from the breaker. So two questions

1) Is this a bad idea?

2) Is there a way to test the cable for juice while uncut? I'd like to pick one with less load as to not overload the breaker, but with several wires I don't know which run to which breaker.

Wall

Cable

[Guest bkelm18]

For testing to see if a wire has electricity running through it, go to Lowes or Home Depot and pick up a non-contact voltage tester. They're pretty inexpensive. You just hold it near the wire you want to check and it will beep if it detects electricity. Looks like this:

http://www.lowes.com...Id=10151&rpp=24

If you're wanting to check to see how much current is running through it, you'll need a clamp type testor. Like:

http://www.lowes.com...rent&facetInfo=

Edited April 8, 2012 by bkelm18

[Lumber_Jack]

Thanks bkelm. I just want to avoid putting it on the kitchen breaker, pretty much. And I can do an on/off test with that meter and the breakers. I'll stop buy and pick one up. Thanks

[Guest Lester Weevils]

Hi Lumber_Jack

If I mislead hopefully someone will correct it.

If the breaker will handle your extra load I believe you would install a junction box where you want to splice in (mount the junction box up in the vicinity of the pre-existing cable up in your joists) and then wire the splice connection inside the box. If that wall is sheetrock then you could cut a smallish hole at the top of the wall and cut an outlet hole at the bottom and use a fish wire to pull your new cable thru the wall. You can buy plastic outlet boxes with adjustable ears that will blind-mount in a sheetrock wall. The ones I like best also have depth screw-adjusters, so that after the box is mounted in the wall, you can use a screwdriver to adjust the box depth so it is exactly flush with the wall after your outlet cover is attached.

If you don't want to fish wire in the wall or you can't fish wire (concrete wall or no air-gap behind the wallboard) then you need a surface-mount metal box and the wire run down the wall ought to be in metal conduit. Perhaps plastic box and conduit would be legal, but IMO metal would be better for an external wiring run.

The meters cost a little but can be useful to have. Maybe overkill just to run a single circuit, but OTOH good meters last a long time if you take care of em. I have a 30 year old Fluke 77 that still works fabulous for general electronic work but it isn't "ideal" for house wiring and lacks some features present on newer meters.

Last year bought from Home Depot a Klein Tools CL2000 that looks pretty nice for occasional electrical work and other tasks as well. Though the fluke may still be better on some electronics. That Klein CL2000 is a true RMS meter with clamp-on capabilities and a couple of nice features such as capacitance metering.

One feature is a method to determine if a circuit is hot. There is a button labeled "NCV", and there is a little plastic nub on the top of the clamp-on. If you hold the NCV button and move the little plastic nub within a few inches of a hot wire, the meter will start beeping. If you hold the NCV button and can touch the tip of the clampon right on the insulation of a piece of romex, and move the tip up and down the wire, and the meter doesn't do some beeping, then there are really good odds that the wire is NOT hot.

You often have to cut outside jacket from a cable to measure the current with the clamp-on. Usually clamp-on's need ONE wire in the circuit inside the clamp-on sensor. So if you have a piece of romex with all three wires inside the overall jacket, you have to cut back the outside jacket and get the hot or neutral wire physically isolated a few inches from the others before you can accurately use the clamp-on.

I have two very fun Sperry tools, available at Home Depot and others. One is a sperry circuit tester which consists of a transmitter that can plug into an outlet or screw into a light socket, and a handheld receiver with an insulated "tip". So if you want to learn about your bedroom circuit, plug the transmitter in your bedroom outlet, then go to your breaker box and touch the receiver to each breaker. The breaker attached to your bedroom will make the receiver beep, and usually none of the other breakers will make the receiver beep. Then you can trace the wire out of the breaker box by following the "beeping wire" to every place that is on that breaker.

Sperry also makes a fabulous tool for tracing UN-POWERED AC circuits and all sorts of UN-POWERED low-voltage circuits. It is a "Wire Tracker". It has a transmitter with many different outlet jacks, BNC, ethernet, telephone, alligator clips. And a receiver that works kinda like the above Sperry circuit tester. So if you want to trace a cable TV or ethernet or UN-CONNECTED AC line, connect the transmitter to one end and then identify the correct cable in the bundle on the other end with the little receiver.

Edited April 7, 2012 by Lester Weevils

[dralarms]

Why not just run it from one of the other outlets?

[Lumber_Jack]

Hi Lumber_Jack

If I mislead hopefully someone will correct it.

If the breaker will handle your extra load I believe you would install a junction box where you want to splice in (mount the junction box up in the vicinity of the pre-existing cable up in your joists) and then wire the splice connection inside the box. If that wall is sheetrock then you could cut a smallish hole at the top of the wall and cut an outlet hole at the bottom and use a fish wire to pull your new cable thru the wall. You can buy plastic outlet boxes with adjustable ears that will blind-mount in a sheetrock wall. The ones I like best also have depth screw-adjusters, so that after the box is mounted in the wall, you can use a screwdriver to adjust the box depth so it is exactly flush with the wall after your outlet cover is attached.

If you don't want to fish wire in the wall or you can't fish wire (concrete wall or no air-gap behind the wallboard) then you need a surface-mount metal box and the wire run down the wall ought to be in metal conduit. Perhaps plastic box and conduit would be legal, but IMO metal would be better for an external wiring run.

The meters cost a little but can be useful to have. Maybe overkill just to run a single circuit, but OTOH good meters last a long time if you take care of em. I have a 30 year old Fluke 77 that still works fabulous for general electronic work but it isn't "ideal" for house wiring and lacks some features present on newer meters.

Last year bought from Home Depot a Klein Tools CL2000 that looks pretty nice for occasional electrical work and other tasks as well. Though the fluke may still be better on some electronics. That Klein CL2000 is a true RMS meter with clamp-on capabilities and a couple of nice features such as capacitance metering.

One feature is a method to determine if a circuit is hot. There is a button labeled "NCV", and there is a little plastic nub on the top of the clamp-on. If you hold the NCV button and move the little plastic nub within a few inches of a hot wire, the meter will start beeping. If you hold the NCV button and can touch the tip of the clampon right on the insulation of a piece of romex, and move the tip up and down the wire, and the meter doesn't do some beeping, then there are really good odds that the wire is NOT hot.

You often have to cut outside jacket from a cable to measure the current with the clamp-on. Usually clamp-on's need ONE wire in the circuit inside the clamp-on sensor. So if you have a piece of romex with all three wires inside the overall jacket, you have to cut back the outside jacket and get the hot or neutral wire physically isolated a few inches from the others before you can accurately use the clamp-on.

I have two very fun Sperry tools, available at Home Depot and others. One is a sperry circuit tester which consists of a transmitter that can plug into an outlet or screw into a light socket, and a handheld receiver with an insulated "tip". So if you want to learn about your bedroom circuit, plug the transmitter in your bedroom outlet, then go to your breaker box and touch the receiver to each breaker. The breaker attached to your bedroom will make the receiver beep, and usually none of the other breakers will make the receiver beep. Then you can trace the wire out of the breaker box by following the "beeping wire" to every place that is on that breaker.

Sperry also makes a fabulous tool for tracing UN-POWERED AC circuits and all sorts of UN-POWERED low-voltage circuits. It is a "Wire Tracker". It has a transmitter with many different outlet jacks, BNC, ethernet, telephone, alligator clips. And a receiver that works kinda like the above Sperry circuit tester. So if you want to trace a cable TV or ethernet or UN-CONNECTED AC line, connect the transmitter to one end and then identify the correct cable in the bundle on the other end with the little receiver.

Thanks Lester great advice.

I would install a junction box and just fish the wire in the drywall as its uninsulated, and just forms the under-stair closet.

[Lumber_Jack]

Why not just run it from one of the other outlets?

It would take almost 35' of cable to reach the nearest outlet. That's following the wall up and across the joists. I know cause I already measured. I just saw the 12/2 there, staring me in the face and started thinking. I've never done this before so I was just asking to see if that's my best option.

If running it off another outlet is better, I can do that. Thoughts?

[Guest bkelm18]

There's nothing really wrong with just adding a junction box. Personally, all else being the same, I'd go the route with the shortest run of cable.

[Guest Lester Weevils]

I'd go with bkelm18's judgement that shorter run would be better. IIRC, bkelm18 actually does if fer a living. If you have to run across-joists, maybe I'm wrong but believe that codes expect the cable to feed thru holes drilled a few inches up each joist, rather than just tacking the wire along the bottom of the joists. I think that is to make it less likely that the cable could get accidentally cut and electrocute somebody. Just sayin, it would be a PITA to drill a bunch of half inch holes in the joists with a right-angle drill.

[Guest bkelm18]

I'd go with bkelm18's judgement that shorter run would be better. IIRC, bkelm18 actually does if fer a living.

Used to. Got tired of monkeys throwing poop at me.

[analog_kidd]

Your challenge in splicing into an existing run will be getting enough slack to splice the two cut ends back together, and then tie the new line into it. You'll need at least a few inches of extra wire pulled from somewhere. Once you cut it, you might be able to pull some back and reroute it to cut a corner somewhere.

Put all the splices into a junction box. Use wire nuts to connect them all together, and I like to wrap electrical tape around the wire nuts and wire, just to make sure they don't come loose. Make sure to get the cover for the box so everything stays put.

In the wall you'll need to get what they call an "Old Work Box". It has little tabs that when you turn the screws attached to them, the tabs turn in behind the drywall and snug up. You can use a washer tied to string to fish a line down to the box.

Like BKelm says, they make s tester that tells you when you are close to a live wire. Another test tool that is very handy is a little plug you stick in the outlet that tells you if the outlet is wired correctly. It has three lights on the front that light up differently for different conditions, such as no ground, or polarity backwards. They are fairly inexpensive. They can be used simply to tell if the outlet has power. No lights means no power.

You can also pick up a multitester for about $10. Trust me, you'll find uses for one if you own it. You can use one to test for a live connection.

Good luck and be safe.

[Guest bkelm18]

Another test tool that is very handy is a little plug you stick in the outlet that tells you if the outlet is wired correctly. It has three lights on the front that light up differently for different conditions, such as no ground, or polarity backwards. They are fairly inexpensive. They can be used simply to tell if the outlet has power. No lights means no power.

Those are great to have. Nothing worse than finding out you crossed the hot and neutral the hard way.

[Lumber_Jack]

Your challenge in splicing into an existing run will be getting enough slack to splice the two cut ends back together, and then tie the new line into it. You'll need at least a few inches of extra wire pulled from somewhere. Once you cut it, you might be able to pull some back and reroute it to cut a corner somewhere.

Put all the splices into a junction box. Use wire nuts to connect them all together, and I like to wrap electrical tape around the wire nuts and wire, just to make sure they don't come loose. Make sure to get the cover for the box so everything stays put.

In the wall you'll need to get what they call an "Old Work Box". It has little tabs that when you turn the screws attached to them, the tabs turn in behind the drywall and snug up. You can use a washer tied to string to fish a line down to the box.

Like BKelm says, they make s tester that tells you when you are close to a live wire. Another test tool that is very handy is a little plug you stick in the outlet that tells you if the outlet is wired correctly. It has three lights on the front that light up differently for different conditions, such as no ground, or polarity backwards. They are fairly inexpensive. They can be used simply to tell if the outlet has power. No lights means no power.

You can also pick up a multitester for about $10. Trust me, you'll find uses for one if you own it. You can use one to test for a live connection.

Good luck and be safe.

Thanks for the help. If you can see in the pic there is some slack in one of the lines, so I think I can get the junction in there. I appreciate the tips, I'll pick up both testers before venturing into the job.

[Guest Lester Weevils]

Another test tool that is very handy is a little plug you stick in the outlet that tells you if the outlet is wired correctly. It has three lights on the front that light up differently for different conditions, such as no ground, or polarity backwards. They are fairly inexpensive. They can be used simply to tell if the outlet has power. No lights means no power.

You can also pick up a multitester for about $10. Trust me, you'll find uses for one if you own it. You can use one to test for a live connection.

Yeah that little three-light plugin polarity tester is nearly essential. Very valuable little gadget. When I was playing music, that polarity tester was used first thing on every stage outlet before anything got plugged in. Just to make sure I knew what I was dealing with. Some stage wiring is pretty dang bad. But it doesn't completely protect against if some idiot faked 110 by using one leg of three-phase, and compounded the error by doing it on both sides of the stage, using different legs.

A cheap multimeter is better than none, and budget drives purchase decisions. A multimeter up in the $100+ ballpark, in my experience, is more likely to be durable and accurate. But maybe the cheap ones are better nowadays than in the past.

One problem with the really cheap ones is that the inputs may not be high-impedance. Which may not be a big deal on an electric circuit, but sure can be a big deal if you poke a probe the wrong place in a transistor circuit.

[nightrunner]

Make sure whatever line you splic into is hot all the time and not switched if you cant visually trace it down on both ends.

[analog_kidd]

Make sure whatever line you splic into is hot all the time and not switched if you cant visually trace it down on both ends.

That reminds me of when my son bought his house, there was an outlet in one of the bedrooms that would intermittently not work. We plugged a light in to the outlet and started troubleshooting it. After checking and retwisting the splices and connections and making sure everything looked good, it all worked fine. Then it stopped again. After scratching our heads for a while, the light came back on. That's when I realized that his wife was doing laundry on the other side of the house. I shouted for her to turn on the light in the laundry room, and what do you know, the light came on in the bedroom! Someone had tapped into the laundry room circuit to power the bedroom outlet, but they tapped into a switched leg.

[Lumber_Jack]

Ah, good advice. I think coming from the basement I should be fine. But once I determine the breaker the line is on, I'll double check that it's not switched.

[hornett22]

Those non contact testers are awesome. Look for the non adjustable one if they have it.

[Guest bkelm18]

Those non contact testers are awesome. Look for the non adjustable one if they have it.

Yeah don't get the adjustable one. I hated those.

[subsonic]

Make sure you don't bury the junction box.....if you ever decide to drywall your ceiling, it's against code for them to not be accessible. The previous post about having difficulty splicing a cut in an existing line is spot on. I did remodel work for 25 years, I'd be skeptical of having enough slack based on your photo. The other dynamic to consider is where in the existing circuit, aka "run", you're interested in adding the outlet, that may affect the type of receptacle you need and how it has to be wired.

Just noticed the light switches on the wall.....why not grab the feed from there?

Edited April 9, 2012 by subsonic

[dickenscpa]

You'll have to drill holes through the joists if you decide to drywall that ceiling. But you're not allowed to have a junction box behind drywall anymore. Is the line you're going to tap going to a light fixture? Depending on whether it's a line or load, your lightswitch could end up turning off your outlet.

If it's 12g wire make sure you tap with 12g. It's going to a 20A breaker and that's too hot for 14g.

I agree with subsonic, tap that light switch. Make sure you get the feed and not the switchleg though so the switch doesn't control your outlet. My Dad always taught me "hot on the left and switch leg on the right" but that was just his preference in case we ever had to go back. I don't think that's a hard fast rule. Like now it's pretty universal that black is hot, white is neutral and bare is ground. Back in the old days it was the electricians preference. Been in some older houses doing an add on and found out that white was hot.

My Dad owned a plumbing&electric company for 46 years. From the time I could walk every weekend and every summer vacation he worked my tail off until I graduated college. No Christmas vacation, no Spring Break trips - I worked. One summer between college years he agreed to finish a job on elec and plumb someone else started. He NEVER did that but this was an opportunity to get in with a new GC.

He drops me off with tools and material and leaves. I was in college 1990-1994 so everyone and their dog didn't have cell phones at the time, neither did I. I was gonna put my stick copper under the house to finish up the water line and the closer I got to the crawl space it SMELLED. Previous electrician got his neutral and hots crossed and grounded to the copper the plumber had already ran. Apparently another trade hooked the house up to the temporary to run their power tools. I HATED when they did that instead of running their cords out to the temp. I got a jolt or two from that myself. Anyway the previous plumber that got fired for not finishing the job or returning calls was dead under the house since his copper water line was now hot.

So I'm a teenager stuck out in the boonies all day with no way of calling out and a dead body.

Brad

[Lumber_Jack]

Just noticed the light switches on the wall.....why not grab the feed from there?

Well there is a good reason for that.....I hadn't thought of that . Should I split it in the switch box, or at the top of the wall where the line drops down the wall?

I am assuming I should run the wire up to the ceiling and back down, mid wall, to avoid ripping out drywall.

Essentially I'm looking for the easiest way to get at least one outlet on that wall. And if I could kick the builders ass for not putting them in to begin with I would.

[analog_kidd]

What's on the other side of that wall? If there is an outlet there, you can tap into that and just put a new outlet box on the side we can see in the picture. Just find the studs the existing outlet is in between, find the same studs on this side of the wall and put a box in a little to one side or the other of the existing outlet.

[Lumber_Jack]

What's on the other side of that wall? If there is an outlet there, you can tap into that and just put a new outlet box on the side we can see in the picture. Just find the studs the existing outlet is in between, find the same studs on this side of the wall and put a box in a little to one side or the other of the existing outlet.

The other side is a closet/ stairwell. This is the basement and that's the only drywalled area. The rest is cinder block. There are two outlets on the opposite wall from the picture but they are wired in conduit.

[Guest Lester Weevils]

Lumber_Jack you are getting lots of great practical advice from folks with more expertise on wiring than I could offer. Just wanted to beat the dead horse a little more on a meter, for what its worth. I haven't surveyed every modern meter out there so this info is flawed and incomplete.

Issues with cheap meters I encountered long ago which may still be the case, or maybe not--

1. As earlier mentioned, if in the future you get to a situation where you want to stick the probes into semiconductor circuits, a low-impedance meter can cause things like perfectly healthy transistor amps to spontaneously and catastrophically melt down if you happen to probe the wrong point in a circuit. So unless you want to buy another meter down the line if you decide to try yer hand at electronics, it is good to get one with high-impedance inputs.

2. Cheap meters I've bought never lasted very long before breaking.

3. Cheap meters I've bought came with cheap probes. The probe tips can sometimes look nice and shiny and still have intermittent conductivity, so you have to "scratch around" on connection points and/or measure multiple times to make sure your probes are not contributing to seriously flawed measurements. It just slows things down having to work around bad probes.

4. Cheap probes also tend to fall apart pretty quick, and its a bummer if you are in the middle of work and the wire falls out of your probe and you have to either repair it or go buy new ones. You can also sometimes get intermittencies in the middle of cheap probe cables, so you have to be wiggling the probe wires around in addition to scratching around on contact points, to try to get a reliable measurement.

If I was gonna buy a replacement for my old Fluke 77 then it would probably be another Fluke. The good'uns in the Fluke line look like they are going for about $500 nowadays. And if you wanted clamp-on current measurement you would have to buy a clamp-on adapter to connect to the meter. Think I gave about $200 for my 30 year old 77 so it has costed me about $6.67 per year. Even if one only got ten years life out of a new $500 Fluke, it would only be $50 per year. But that is still kinda stiff for occasional use.

There might be lots better meters for the money, but I've been tickled with that Klein Tools CL 2000, paid about $130 at Home Depot. Amazon has it a few bucks cheaper. It ain't a Fluke but seems built pretty good and all the functions work OK for the money. The probes look pretty durable and ain't broke yet. I didn't have a functional clamp-on attachment for my Fluke 77 any more, and didn't have a non-contact voltage sensor gadget, and the little Klein Tools has both in addition to other goodies.

That amazon listing has decent reviews and they mostly agree with my experience, so there's no need me repeating what is in the reviews. I had noticed the same as the reviewers that the measurement updating is a little slow. Its not near as fast as the old Fluke, but the updating seems fast enough for electrical work that I'd be doing. The non-contact tester works fabulous. It has lots of little features that add value.

Maybe somebody else makes a meter for the same price that is even more gooder. Was just sayin if you happened to have a non-contact voltage sensor and also a meter on your shopping list, this one has both and they both seem to work good for the money. They sell a 2100 with an infrared thermometer, but I'd probably rather have a thermometer in a separate tool. They also sell a cheaper model with almost the same features as the 2000 except it is not a true RMS meter. For many tasks, the true RMS is not a big deal, but it is nice to have.

http://www.amazon.co...r/dp/B003LH7NH2