Electrical wiring question. Woo!

Posted by: Ken.C

Electrical wiring question. Woo! - 10/17/11 11:25 AM

So I was looking to install a ceiling fan in one of our rooms. I need to replace the pan, but that's no problem. What is a problem is that the existing pan has two romexes going into it, and they appear to be on different circuits. Worse yet, the neutral from one is tied to the hot on the other. WTF? Anyone have any clue why this might be like this, if it's safe, and how to deal with it?

I'm probably going to call an electrician, but I'm really curious.

Will post picture of wires later.
Posted by: BobKay

Re: Electrical wiring question. Woo! - 10/17/11 11:39 AM

Ken, this is just a stab. Unfortunatley, each house is as different as the parade of tradesmen who have been through there.

I don't think it's possible for it to have functioned while connected to two different circuits. If there is no sign of heat damage (blackened parts), then it should be OK. If it were causing a problem, it should constantly trip the breaker.

I see stuff that is totally inexplicable, yet, has been there for 40 years w/o issue. When that's the case, I install the new stuff just the way the old stuff was connected. No one has ever called back or sued me to replace their burned out home.

Do you think it may have ever had two on/off switches in separate locations? If it is a separate circuit, is it dead and out of the system, or still live?
Posted by: nickbuol

Re: Electrical wiring question. Woo! - 10/17/11 11:55 AM

Since I've done a few ceiling fan wiring jobs, and am about 800 feet of electrical wiring in my basement finishing project, I can say that to me, it sounds like someone is "hodge podging" the wiring. I've seen it where someone used two 14-2 or 12-2 (2 wires plus 1 ground) wiring "sets" instead of a single 14-3 or 12-3 (3 wires plus 1 ground) wiring sets to run a ceiling fan/light combo where they have separate switches.

That is why I've used SO much electrical wiring and I have about another 200 feet or so to go in the basement (home theater is all that is left) because I want it done right and the cost of using the correct wiring vs. even having to figure out 5 years from now what I wired today to "cut costs" will be worth it. To some people, the cost of the 12-3 or 14-3 wire over 12-2 or 14-2 is too much and they make up electrical wiring as they go.
Posted by: BobKay

Re: Electrical wiring question. Woo! - 10/17/11 12:09 PM

Originally Posted By: nickbuol
they make up electrical wiring as they go.


I think that's definitive, Nick. After ripping apart a client's wall for him, I've seen my electrician cry. Then he talks to our client. Then she cries.
Posted by: Ken.C

Re: Electrical wiring question. Woo! - 10/17/11 12:18 PM

Given the amount of non-working 3 way switches in this place, it wouldn't surprise me. It is a small room, and there's currently only one switch in it, but there's also an outlet in the closet in there, and from looking at other houses in the neighborhood, it clearly was once part of the (formerly) L shaped living room.

Now that I think about it, though, I don't remember if I turned the light switch on when I was testing the power (since I was trying to figure out which breaker the damned thing was attached to. Sssssooooo...

Here's what I know, though. With the breakers (light switch?) off, I didn't get voltage on either loose black or white wire, either to each other or to the ground. I did get ~120V on the black/white mix; I think just to ground, but possibly to the other two wires as well. I guess I'll have to check it again.


Posted by: solarrdadd

Re: Electrical wiring question. Woo! - 10/17/11 02:05 PM

Originally Posted By: Ken.C
Given the amount of non-working 3 way switches in this place, it wouldn't surprise me. It is a small room, and there's currently only one switch in it, but there's also an outlet in the closet in there, and from looking at other houses in the neighborhood, it clearly was once part of the (formerly) L shaped living room.

Now that I think about it, though, I don't remember if I turned the light switch on when I was testing the power (since I was trying to figure out which breaker the damned thing was attached to. Sssssooooo...

Here's what I know, though. With the breakers (light switch?) off, I didn't get voltage on either loose black or white wire, either to each other or to the ground. I did get ~120V on the black/white mix; I think just to ground, but possibly to the other two wires as well. I guess I'll have to check it again.



ken, where in VA are you? i'm in alexandria and i'm a licensed master electrician. if your nearby, i can help.

most of the time when you see a white wire attached to a black or red wire it's a switch leg. what is done is the power from the constant hot is sent down to a two wire switch circuit and the power is sent down on the white wire that attaches to the switch as it's source then the other side of the switch (a single pole) has a black wire sending the power (for ON condition) back out to the load. in the box you should have from that two wire (one cable) a black that attaches to your fan light circuit or a light fixture which ever is in the ceiling (doesn't matter) for a fan usually if there is a constant hot in the box the fan motor ataches to it so that you can have a seperate switch to control only the light fixture portion and this way when you turn the light off at nigh from the switch (could be a dimmer switch or a standard single pole on/off) the fan can continue to run undisturbed by turning of the light at the switch or dimming it.


as for three way switches:
the thing to remember is both switches are the same, one common terminal (usually colored darker than the other two) and then there are two travelers. the only terminal that is of real importance is the common (the darker one of the three) on one switch the 120v hot (power) conductor connects to it (the other two terminals get the travelers, doesn't matter which one of the travelers goes to which terminal) the other switch on the common goes the load (what ever you are controlling with the switch which is usually a light fixture or a receptacle with a lamp plugged into it) and then the two travelers from the other switch go on the remaining two terminals.

with both switches completely removed if you have a good ground only one conductor will give an indication of power when using a proper electrical tester to ground (120v should be your reading) that switch is where the power comes in. once you determine that (don't connect anything yet), go to the next switch three way switch circuit and you need an ohm meter and set it to ohms/resistance and make sure you have your lamp turned on with a standard incandescent lamp in it. when reading to ground, you will read a circuit of resistance. to be certain, turn the lamp off (if it's a lamp in a controlled receptacle) or unscrew the bulb if it's in a ceiling fixture and test it again and you should have an open circuit (infinity or no connection(this is NOT TO BE CONFUSED WITH 0/ZERO which means a short circuit!)for your reading) at this switch the conductor you read resistance to ground from the lamp connects to the common terminal of that switch and connect the travelers back to either of the two remaining terminals, makes no difference.

your 3-way switch circuit is now working properly!

hope this helps.
Posted by: tomtuttle

Re: Electrical wiring question. Woo! - 10/17/11 02:13 PM

Epic win by solarrdadd! Great information.
Posted by: Ken.C

Re: Electrical wiring question. Woo! - 10/17/11 02:43 PM

I'm going to have to spend some time digesting that one. I'm in Loudoun County, up near the 7. Thank you!
Posted by: solarrdadd

Re: Electrical wiring question. Woo! - 10/17/11 04:02 PM

Originally Posted By: Ken.C
I'm going to have to spend some time digesting that one. I'm in Loudoun County, up near the 7. Thank you!


that's about an hour or so from me. pm me if i can be of help!
Posted by: Ajax

Re: Electrical wiring question. Woo! - 10/17/11 05:17 PM

Originally Posted By: Ken.C
I'm going to have to spend some time digesting that one. I'm in Loudoun County, up near the 7. Thank you!
HA! You can always spot a transplanted Californian. In Eastern-speak, that would be "up near route 7," or just plain "7." wink If it were an interstate, it would be "I7", "Interstate 7," or just plain "7" again.
Posted by: BobKay

Re: Electrical wiring question. Woo! - 10/17/11 05:23 PM

Ken, look what it got you! An offer of experienced help to actually come to your house!

Awesome!

Solarrdad is your new Daddy!
Posted by: Murph

Re: Electrical wiring question. Woo! - 10/17/11 05:42 PM

Whose your..... Never mind. You know!
Posted by: tomtuttle

Re: Electrical wiring question. Woo! - 10/17/11 07:07 PM

Good call, Jack. I've tried and failed to figure out where exactly "I-5" (as it is properly known) becomes "the five".
Posted by: Ken.C

Re: Electrical wiring question. Woo! - 10/17/11 07:37 PM

Southern California. Northern California calls it I-5. Or, to use a different example, it's the 405 and it's 580.
Posted by: pmbuko

Re: Electrical wiring question. Woo! - 10/18/11 11:05 AM

I always take the 1 after 909.
Posted by: BobKay

Re: Electrical wiring question. Woo! - 10/18/11 11:29 AM

I know that line. I get off at exit number 9, number 9, number 9.
Posted by: Argon

Re: Electrical wiring question. Woo! - 10/18/11 12:25 PM

I tried to read this backwards but...
Posted by: pmbuko

Re: Electrical wiring question. Woo! - 10/19/11 12:25 AM

I've got blisters on me fingers.
Posted by: Ken.C

Re: Electrical wiring question. Woo! - 10/19/11 07:13 AM

I think I've figured out what's going on (after careful reading of my home repair book on electricity and rather un-careful blowing of a breaker). I think what I'm looking at is pretty simple--a loop circuit with mis-labeled wires. As far as I can tell, instead of recoding the white wire to black at the fixture, some idjit recoded the black wire to white. So I've got a black wire coming back on the return from the switch, and a white wire incoming from the circuit, and two white wires tied together going from the circuit to the switch.

That make any sense? The switch end only has one piece of romex coming in, so that's got to be what's going on.

I had thought I posted pics the other night, but I think I must have gotten distracted and not pressed Submit...
Posted by: BobKay

Re: Electrical wiring question. Woo! - 10/19/11 09:23 AM

I have seen that numerous times and thought about it yesterday as a possibility. It always freaks me out, 'cause I wonder how much of the place is wired that way and how can I know.

I'd still have Solarrdad over for lunch and a couple of beers.
Posted by: MarkSJohnson

Re: Electrical wiring question. Woo! - 10/19/11 11:48 AM

Originally Posted By: BobKay
I'd still have Solarrdad over for lunch and a couple of beers.


Do the electrical work first.
Posted by: BobKay

Re: Electrical wiring question. Woo! - 10/19/11 01:15 PM

Originally Posted By: MarkSJohnson
Originally Posted By: BobKay
I'd still have Solarrdad over for lunch and a couple of beers.


Do the electrical work first.


Killjoy.


Oops! Gotta clarify. It's an epithet, Mark, not a suggestion nor a directive. Now if Buddy starts staring at you and saying "Killjoy," you've got a HUGE problem.
Posted by: MarkSJohnson

Re: Electrical wiring question. Woo! - 10/19/11 01:40 PM

Naaaah.

That's the cats schtick.
Posted by: Ken.C

Re: Electrical wiring question. Woo! - 10/19/11 05:11 PM

Here are the pics (he says, relentlessly keeping the thread on track...)



Another angle:



The switch has a single yellow romex going into it, with the black wire hot when the switch is off.
Posted by: solarrdadd

Re: Electrical wiring question. Woo! - 10/19/11 08:56 PM

Originally Posted By: Ken.C
Here are the pics (he says, relentlessly keeping the thread on track...)



Another angle:



The switch has a single yellow romex going into it, with the black wire hot when the switch is off.


ken, the yellow romex is 12/2 (that's why it's yellow and it's been run recently in the last couple of years that's when they changed the color coding of romex jackets; #10 would be orange)what we can't see is the color jacket of the other cable. based on what i see the black and white cable that you cannot see the sheath is the feed with 120v (black) and the white (looks more bage with the single red wire nut on it) should be the neutral. notice the back is connected to the white of the romex with the yellow sheath, that should send power down to the single pole switch and when the switch is turned on it should come back up to the light fixture with the black conductor (shown alone with a single red wire nut) the light fixture hot should connect to the black and the netural of the fixture should connect to the single white (beige looking) conductor. if this is wired correctly you should be able to turn on and off the fixture attached to this box with no problem.

questions for you:

is there a single pole switch in the switch box? a single pole switch will say "on/off" depending on it's position. it should also have two insulated wires connected to it and in some instances a bare copper ground to the ground screw.

is it a three way switch in the switch box? a three way switch will not say anything on it as it's depending on the position/condition of the other three way switch in the circuit. it should also have three insulated wires connected to it and in some instances a bare copper ground to the ground screw.

which of the above is what you have?

if you seperate the two wires that are connected with the wire nut (black & white) is either one of them hot? once seperated did you lose power in the switch?

another thing is that if you have a compelte circuit for a light fixture, i.e. a single pole switch, a light fixture with an incandescent bulb in it and properly wired conductors between them when you can test the switch to make sure it hasen't failed by putting a tester accross the two terminals of the single pole switch (on/off) and when in the on position you should read no voltage (this is a properly working switch) in the off position you should read line voltage (120v) (this is a properly working switch) if the switch is off and you go accross it with a tester and read no voltage and you notice the light won't turn off then the switch is bad, failed closed (even when you have it turned to the off position) if you have the switch turned on and you read accross the terminals with a tester and you read line voltage and you have a good working fixture and bulb then the switch is bad and you are reading an open switch (the switch has failed open)

get back to me when you can on this. i'm here to help ya buddy!

Oh yeah, pull out the switch, leave it attached to the wires and take a picture of that too!
Posted by: Ken.C

Re: Electrical wiring question. Woo! - 10/19/11 10:00 PM

The other Romex in the pan is a grey cable.

It is a 2 way switch with a ground screw.

I have not separated the wires on the wire nut yet, but I will try that.

I'm not sure I follow the last paragraph. I have measured the voltage on the bottom screw of the switch to the ground wire in the switchbox, and got ~120V, switch off or on. With the top screw and ground wire, I got 120V when the switch is on, but 0 when off.

Here's where I believe I made a mistake: I tried to measure the voltage between the top and bottom screws, which immediately made a rather large spark and blew the circuit breaker. I did not have anything connected to the fixture.

OTOH, I know which breaker that switch and fixture is on, now... which is unfortunately the same breaker the living room light+fan, exterior lights, utility room light, and outlet the AV equipment is plugged into. So I'll need to wait to find the right time to kill the power.

I'll get you the pic of the switch as soon as I do that, as well as the voltage test on the two connected conductors in the pan.

Thank you very much!
Posted by: jakewash

Re: Electrical wiring question. Woo! - 10/19/11 10:51 PM

After having just finished wiring my basement, sounds ike you and SD are on the right track.
Posted by: solarrdadd

Re: Electrical wiring question. Woo! - 10/19/11 11:06 PM

Originally Posted By: Ken.C
The other Romex in the pan is a grey cable.

It is a 2 way switch with a ground screw.

I have not separated the wires on the wire nut yet, but I will try that.

I'm not sure I follow the last paragraph. I have measured the voltage on the bottom screw of the switch to the ground wire in the switchbox, and got ~120V, switch off or on. With the top screw and ground wire, I got 120V when the switch is on, but 0 when off.

Here's where I believe I made a mistake: I tried to measure the voltage between the top and bottom screws, which immediately made a rather large spark and blew the circuit breaker. I did not have anything connected to the fixture.

OTOH, I know which breaker that switch and fixture is on, now... which is unfortunately the same breaker the living room light+fan, exterior lights, utility room light, and outlet the AV equipment is plugged into. So I'll need to wait to find the right time to kill the power.

I'll get you the pic of the switch as soon as I do that, as well as the voltage test on the two connected conductors in the pan.

Thank you very much!


that means the switch works as it should and it's a single pole (not a 2 way!) with circuit wires on a switch that has 2 screws (not counting the system ground screw)

what happened when you went accross the switch it sounds like you accidentally grounded one of the meter terminals to the grounded switch causing a short circuit to ground, which trips the breaker. check the switch and the leads on your meter. the switch should show arc marks and carbon spatter from the energy released; the meter lead(s) will have a piece missing from it as it was welded onto the switch or off!

so far everything looks like it's wired ok. you simply need to put it back as you took it apart once you connect it up to your fan.

once you replace the box with a fan rated box and mount it properly to the wall here is what you should do:

based on one of your post

"Here's what I know, though. With the breakers (light switch?) off, I didn't get voltage on either loose black or white wire, either to each other or to the ground. I did get ~120V on the black/white mix; I think just to ground, but possibly to the other two wires as well. I guess I'll have to check it again. "

this means that the black wire that's connected to the white switch leg is the constant hot, this is correct and good.

after your box is mounted connect the constant hot black back to the switch leg (the yellow romex) white conductor the other black conductor from the switch will bring power to your fan light fixture and the wire from most fan kits for the light switch is blue (verify this with your fan installation instructions)
next, both your fan motor and light fixture neutrals (both should be white) get connected to that white wire that looks beige with the red wire nut on it. the fan motor should be a black conductor and connect it to the black/white wire under that wire nut. the reason for this is that the switch will turn on and off your fan light only (pull the pull chain on the fan for the light and leave the pull chain alone from then on only controlling the light with the wall switch. the fan motor is controlled by the fan speed pull chain. now you can turn the light on and off independent of the fan so on hot nights you can turn the light switch off and the fan will continue to turn. if you have a fan with a standard incandescent lamp you can use a dimmer switch to dim the lights. you cannot use a dimmer if your fan light kit has compact flourescent type lights again, read your fan kit instructions carefully.

hope this makes some sense; please keep me posted. wink
Posted by: Ken.C

Re: Electrical wiring question. Woo! - 10/20/11 07:22 AM

Cool, yeah! I'll need to look at it to make total sense of what you're saying, but I think I follow. That would definitely be better than how the other fans are wired (everything to the switch), not that I'm going to fix them...

I did take chunks out of the probes, definitely.

So that makes a little more sense on why I tripped the breaker. I was wracking my brain trying to figure out why connecting two leads at the same potential would do that--it just didn't make sense! But why was I OK, intentionally touching the ground wire and one of the hot wires?