Weird electric problem.

[scorrpio]

I am presently renovating one of upstairs bedrooms. One of small closets is getting reframed and widened, and will accomodate a built-in entertainment center. For that, I also needed to have outlets inside that closet.

Removing drywall exposed a cable running through framing there. It was very convenient - I could just cut into this one instead of running new cable. The cable appeared on same circuit as all other outlets in this room.

When I cut into it, I noticed that cable is a 3-conductor (white, black, red, ground) which was strange, cause all other wiring in this room is 2-conductor, and there is no 240V service anywhere on 2nd floor. Wire is 14 gauge copper. I put in the box, made sure ground was uninterrupted, connected red wire straight through, and wired outlets between white and black - all as it should be.

Well, here's the problem: this new outlet appears to have very low power. The multimeter shows 120V AC, but when I plug in my 4.5amp drill, it won't work. Dremel did work, but did not seem to go full speed. A table lamp worked. My 10amp electric brad nailer did not work. And this new outlet is on same circuit as other outlets in the room. Other outlets have no problem powering even my 13amp circular saw.

What do you think could cause this? What to check for? I mean, the outlets will likely be fine powering a small TV and maybe a bookshelf stereo, but this low power is bugging me. Thanks!

[TheRic]

Working on older houses is always a trip. I’m sure it made sense when it was put in, but years later it leaves people scratching their heads.

Since the outlets are 2 wire (black, white, no ground) and this wire is 3 conductor with ground I’m going to guess that this wire was put in later. The 14-3G wire could be a switching wire for some 3-way light switches, or maybe split receptacles (probably not this case). I have also seen were they would run 14-3 (or 12-3) to a section of the house then split it from there (as in red for Bedroom #1, black for Bedroom #2, share the neutral). Maybe they only had 14-3G left and needed to get the job done.

You might want to find out were the line comes from / goes to. When someone turns off that switch in the garage the power to the entertainment systems could go off, with less than minutes to go, with your team down by 4, marching down the field!! There also could be some motor on the same line (attic fan) that when it’s on will give you nice wavy lines across the TV, and static on the speakers!!

It sounds like you are getting bleed over onto the black wire. The real line is probably the red wire. I would test the red wire for voltage, and amps (try your drill / saw / etc). Got a feeling you will get a decent voltage and amps.

[Hellrazor]

There are a few things 14-3 can be used for. I doubt its 220 unless someone ran it for an AC window unit, but using 14g is not good.

It could be a multiwire circuit, check if both black and red are carrying current. The neutral and ground would be shared for each circuit.

Or..

It could be a switched circuit for lighting.


Also, what type of meter are you using? Digital meters sometimes show phantom voltage. I perfer a 'tick' tester (search sears.com for fluke volt meter) or a standard meter as a backup.

Did you wire pigtails for the black and white or did you connect everything to the outlet terminals?

Another quick way to see whats going on, buy an outlet tester. The ones with the lights on top that tell you whats going on. They are about $5.

Another reason your outlets might not work right, tools have a polarised plug. If you wired the outlet backwards tools will not work while a non-polarized plug for a lamp would.

[just4funsies]

I'd be willing to bet it's a switched circuit. Probably runs between a wall switch and an outlet or ceiling fan.

[crokett]

The three wire circuit is used a lot for 3-way switches and/or when you want one leg of a circuit switched and the other not switched. As for the low power, you could have something is wired in series somewhere, instead of parallel. Your tool plugged into the outlet completes the circuit but there is very low power available. Did you connect the new outlet to the red or black?

[scorrpio]

My multimeter is an old one, with a dial rather than digital readout. Worked well for past 13 years, so I have no reason to suspect it.

I'll try to describe my room electric layout.
This particular cable I cut into comes up through the wall base plate, and goes through a stud sideways angles upwards, and seems to go into the attic. Being the only one coming from below, I suspect it's the feeder cable. Will need to check tonight.

I will need to make sure, but I think that there, it goes towards the fan/light fixture. If so, from that fixture, another cable (a 2 conductor) runs back through the wall to a wall switch. Interesting thing though - that switch does not control the fixture. The switch box is a junction box from which 3 other cables branch to other outlets. One of those cables hot is wired through that switch, and it goes to the outlet directly below - this outlet is what this switch controls. That outlet, btw, has full power when switch is on. The fan/light is turned on by pullchains.

Guess I'll need to see how this fan is wired. Yeah, quite possible I'll get full power in the outlet by using red wire instead of black...

[TheRic]

IF the 14-3G goes to the light/fan I’ll bet that wire was added later, specially since it’s with ground, and the others are without ground. Seen older homes that had no ceiling lights, only switched receptacles. Might want to also check out the panel box. It's possible the black is not hooked up. You could then use the black for the entertainment system, and leave the red for the light/fan. It's also possible the white is not making that good of connection.

[Stick]

My house is wired that way, there are ceiling fans in every room. Fan motor feed is live all the time, switched only by the pull chain, Lights are switched.

The low power to me signals a bad connection or a weak breaker. Allows full voltage, but not full current.

[scorrpio]

Well, guess what - it was a traveler cable between top and bottom staircase switches. Though beats me how it could have ended up in THAT spot.

I patched the cable up, and will be dropping another cable from the attic to the box for the outlets.

[scorrpio]

I am convinced now that this is either a very sloppy DIY job or the electrician had too many beers. The attic has a ventilation fan that is hooked up to a temperature/humidity sensor, plus there is a switch to shut the fan off. Seeing how fan is sensor-controlled, the switch is always on. The attic also has lighting installed, which also has a switch.

But check this out: The never-used fan switch is "conveniently" located on the wall in a bedroom right under the pull-down attic staircase. However, the *light* switch is located far in the attic. In particular, you have to crawl on your knees more than halfway through the dark attic in order to get to that switch. I also checked the wiring job: the wire nuts in the boxes are barely holding on: half a turn, and the nut goes off, and the wires separate.

Before I change all that, is there any sort of code or regulation that says that attic fan switch has to be accessible from outside the attic? Or that attic light switch has to be inside the attic? Cause I am about to swap those switch functions...
Thanks!

[TheRic]

Might want to look into having both switches in the bedroom. When I read the part about having the fan switch in the bedroom, the first thing to hit my mind was: "It was put there to allow someone to turn it off at night, so they can sleep better".

In older homes you will find what looks like strange wiring. Remodel this and that over time, add this and that over time, and it will start to look very strange.

[scorrpio]

The fan itself is pretty quiet, and there is like 12" of R30 insulation between the bedroom and the attic. Can't hear it from bedroom when it is on, even when the attic door is open - the insulation dampens the sound.

Besides, when fan turns on, it's for a good reason. I mean, you don't turn off the heating boiler in the middle of a winter night? I wouldn't want someone to accidentally turn the fan off, and leave it like that, only to find my attic moldy and rotten half a year later...

[TheRic]

I don't know of any code that says you have to have it that way, but then again I'm more than a few years out of practice. We normally put the switch at the top of the pulldown ladder on a joist. So when you are about 2-4 steps from the top you can reach the light switch. This frees up wall space.