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lee polowczuk
08-04-2007, 12:04 PM
I had a bathroom ceiling fan on a switch.

i replaced the fan and hooked it up to a new switch -- with two off and on's on one post

please forgive my electrical ignorance.

i want to run a separate light fixture off the second switch... so i ran the wire from the switch to the light... the light has no power.

do each of these switches need to have their own power source?

i guess i am thinking the circuit to the fan would supply power to the light as well.

frenchie
08-04-2007, 12:10 PM
I can think of so many different ways this might be configured... where is the power coming in from - the switch box, or the fan box? A diagram would help...

Mikey
08-04-2007, 01:02 PM
In general, the power source (e.g., black wire from the panel) goes to the common side of the dual switch, and the other two (switched) sides go to the appliances' hot sides. The appliances share the neutral. As Frenchie points out, the topology is slightly different if the power comes from the panel to the switchbox or the fan's box, but a few minutes spent with a pencil and the back of an old envelope will be well spent to get the picture of what's going on.

lee polowczuk
08-04-2007, 01:23 PM
boy, I am sure both of you guys would be a tremendous help.

I just have to figure out some of the terminology.

Some of this is difficult because the fan wiring is in the attic... since it worked fine, i just hooked it up to the top switch

then i put a can light in the ceiling and ran wiring from it down to the lower switch, black to brass colored screw, white to black colored screw, ground to green colored screw.


my guess is either that white wire or the black wire from the can light has to be tied to the fan switch

you can laugh a little... i am patient.

hj
08-04-2007, 02:58 PM
I can't follow your wiring, but by hooking the white to the switch, it in effect became a black, red, or blue wire, not a white one. You still need to find a source for a white neutral wire to the fixture. And that is assuming the "black" wire is actually connected to a "hot" wire.

Mikey
08-04-2007, 05:34 PM
Since you "just hooked it up to the switch", I assume there were only two wires going from the fan box to the switch box -- probably a black/white pair. Another black/white pair should have brought power from the panel to the fan box. The black wire from the panel (the "hot" wire) should have carried current via the black wire to the switch, where it was switched on and off to the white wire (which should have been marked with black paint or tape). Back in the fan box, the white wire from the panel (the "neutral") should have been connected to one of the fan wires, and the white wire from the switch box (which also should have been marked with black paint or tape) should have been connected to the other fan wire. The complete circuit is then hot from the panel, through the switch, through the fan, and return to the panel via the neutral.

Now we introduce the double switch. If you look at the switch terminals, one side of the switch will have two black screws in 2 brass strips connected by a small tab, the other side will have two brass screws in two separate brass strips, each obviously associated with one of the individual switches. The black wire from the fan box should be connected to one of the black screws, and the white wire (which should have been marked with black paint or tape) should be connected to one of the screws on the other side of the switch. Notice that the black ("hot") wire from the fan box is now actually feeding both switches, via the little tab connecting the two halves of the brass strip -- the 2nd switch is all dressed up with no place to go, i.e., nothing's connected to it.

Now to connect the light, you've somehow got to get a wire from the other separate screw on the switch to one side of the light, and the other side of the light to the white neutral wire from the panel in the fan box. How you do this is up to you, but in new construction I'd run a three-wire cable from the fan box to the switchbox (one "hot", 2 switched) and another 2-wire cable from the fan box to the light box (one switched, one neutral).

Draw some pictures and it might make sense. Of course if any of my initial assumptions is wrong, none of this works. If that's the case, do what Frenchie suggested and draw us a picture, or describe what's going on in all 3 boxes (fan, switch, and light) in detail.

Mikey
08-04-2007, 06:23 PM
Okay, I just studied your description a bit. I think you can make all this work by disconnecting your existing light-to-switch white wire at both ends. Then connect another white wire (the white wire in a two-wire cable works OK) from the light to the white wire from the panel in the fan box. Logically, we're moving the end of the light-to-switch white wire from the switch to the system neutral.

hj
08-04-2007, 07:09 PM
That description is not much better than the original one. He is probably already using the "white wire in the romex" for the switched lead to the fixture, and what does he do with it once he disconnects both ends? But he probably does need another white wire for the neutral, we just don't know how he is going to run it.

jadnashua
08-04-2007, 07:48 PM
WIthout being there and measuring things, it is hard to say, but this is my guess.

At the fan, there's two cables coming into it; one from the power panel, the other going to the switch. The white wire coming from the power panel is connected directly to the fan. The black wire from the panel is jumpered to the other wire that is going to the switch. It goes down to the switch, and when the switch is closed, it comes back to the fan on the white, which is connected to the black wire to the fan, providing it with power. BTW, this wire is supposed to be labled with a red marker to indicate that it is a switched hot lead, but is ignored way too often.

So, you need to verify this, and you need to continue the white wire from the power panel to the white wire of the new light. Then, with the new lead from those lights to the new switch, at the switch for the fan, connect both black leads together with a couple of pigtails, and then go to each of the switches, providing power to both items when their respective switches are closed. Leave the white wires where they are, but mark them with red tape or a red magic marker.

The grounds need to run all the way through each item, but I left that out.

If you don't own one, you need either at the minimum a test lamp, or a meter.

frenchie
08-05-2007, 03:00 AM
I'd run a three-wire cable from the fan box to the switchbox (one "hot", 2 switched) and another 2-wire cable from the fan box to the light box (one switched, one neutral).


You were doing so well - but that "one hot 2 switched" is wrong - it'd be one hot, one switched, and one neutral. Like HJ said, what Lee's probably missing is a neutral for the light circuit. Assuming that by wiring in the attic, he means the power enters there...

By the way, ALL of you are wrong about the white wire marked as hot. If you re-designate a white, it can't be the switch leg returning to the light, it has to be the constant "always hot" wire.

http://forums.jlconline.com/forums/showthread.php?t=38064&page=2

(I always hesitate to link to JLC... it's a pro-only site, and we/they can be mean about it. If you're not in the trades, feel free to lurk, but do not post unless you like getting flamed.)

The idea is that, at the fixture's connections, you're always going black-to-black, white-to-white, no matter what, it saves on confusion for the next guy.


Lee - describe each box, will ya please? How many wires in each box, and where do they go?

Do you have access to the attic? Or are the walls open? It'd help to know where it's easier for you to add a wire, because you're gonna have to do it somewhere.

lee polowczuk
08-05-2007, 06:10 AM
I will print and follow these posts..

here's the best i can tell... power came from the basement panel..up the wall to the ceiling to a junction box... then it split... to the fan... and then back down the wall to the original switch.. there, a pair of wires was attached to the switch..

everything worked well.

then i took out the single switch and attached the fan to the top switch.. fan works great..

then i put the can in the ceiling and ran romex from it down to the other switch.

Please allow some patience for my ignorance.. I will take a Sunday break... and thank everone for their help...

i'll let you know next week, where I am ..... even with A/C ,,,it seems to hot to work today...

regards,

Lee
Greenville, SC

hj
08-05-2007, 06:58 AM
Those two wires down to the switch are both "hot" when the fan is on. You do not have a white neutral to the light, so it cannot work. If the black wire is the switched leg, then the white one is "hot" which can be more confusing, and dangerous to a DIY person. I would rather have him confused by the wiring than in the emergency room because he touched a "safe" white wire. And if it happened to me, I would be looking for the idiot that wired it that way.

lee polowczuk
08-05-2007, 07:56 AM
Just to let everyone know some more info..... the ceiling is more or less buttoned up now.

the wall is still open. And, there is romex coming up from the basement into a wall plug box (the plug is in the adjoining bathroom) A wire comes out of that same box and feeds another light switch.

I presume that's a possible solution to complete the circuit. I need to take a breather.

They should teach this stuff in high school rather than another history class. I tried to decipher it in books, but forget it.

HJ--- i'll play it on the safe side, I keep running up and down the stairs from the basement, turning the breaker off an on...

Actually most of the wiring looks decent.. it's a 1930's bungalow...but all of the knob and tube has been replaced...

Mikey
08-05-2007, 08:51 AM
I said "one hot, two switched", and that is in fact the situation, although I would have been wrong about the colors. Having read through the Code (God, I wish they had had an English major on the team that wrote the damned thing) and the JLC thread, I now see that my "one hot" would be the reidentified white conductor (coming from the black in the light outlet and going to the common switch terminal), and the "two switched" would be the black and red conductors (coming off the switched terminals and returning to the fan and light) in a "standard" 14-3 cable.

Someday I'll figure out how to draw pictures for this forum and save a hell of a lot of words.

frenchie
08-05-2007, 04:01 PM
If he runs a 3-wire, there's no need redesignate the white, anyways - it'll be one hot, one switched, one neutral. I think you missed what I was saying.

Anyhow...


Drawings? Google Sketchup!

Give me a few minutes... here we go!


Lee - replace the 2-wire cable between the fan & the switch with a 3-wire cable. This is how it should look when you're done.

lee polowczuk
08-05-2007, 07:47 PM
frenchie...do you want me to pigtail the two whites?

I have tried that (then the brass side has no connections)

the blacks are each tied to their respective black screws.

the fan still works that way....

i am sure it won't be too difficult with all this advice coming in...

First thing monday morning... I will draw a sketch, scan it...and post it.

frenchie
08-05-2007, 11:24 PM
Yup, pigtail the whites. That's the critical connection you're lacking, right now.

If the 2 screws on the "hot side" of your switch is still connected by the little tab, it only needs one black wire connected to it - the one bringing power to the switch. If the tab's been broken off and thay are completely independant, then you need to pigtail that black, and connect to both screws.

Making sense, yet?

The other black, that goes to the light, is now a switch leg - like the red is for the fan - it goes on the OTHER side.


...if this still isn't making sense to you, I really think you should call in a pro.

lee polowczuk
08-06-2007, 07:02 AM
Let's see if this makes any sense.

Frenchie... i think i am catching on.

Pigtail whites.

Attach fan black to upper switch

Attach light black to other side of lower switch

frenchie
08-06-2007, 07:11 AM
Sorry, man, I can't make out your drawing, it's too small - and I can't seem to zoom it. And what I can see, ain't making much sense... Can you zoom it in & crop a bit or something?

WAIT A MINUTE! There's a junction box somewhere in all this? Please explain, with a LOT more detail...

I had thought there were only 3 boxes involved, kinda like this:

jwelectric
08-06-2007, 08:05 AM
Frenchie

I copied his drawing to paint and enlarged it and it still makes no sense.

No he hasn't got it yet!!!

Edited to add;

Does this help you understand why some of the people at JLC get the answers that they get in The Electric Shop?

Over there the people are supposed to be professionals trying to do the same thing that is being done here. Do you think that a real professional would try something this far outside their knowledge?

Keep up the hard work and he will get it sooner or later.

lee polowczuk
08-06-2007, 09:03 AM
I know i will get it....

if you guys were here..it would probably take 2 minutes to figure out.

I'll keep you posted..and try not to bug you any more

jwelectric
08-06-2007, 09:33 AM
Take a minute and explain just what you have.

Start with where the power is coming into and go from there.

Ie;
Is the power coming into the same box with the switch or is it coming in the box with the light?

Are both fan and light coming into the switch or are they going to a different junction box?


Start with where the power is coming into and go to each point that you are wanting to control telling the type of cable you have installed.

lee polowczuk
08-06-2007, 10:23 AM
Here is the way I understand it.

The old fan worked fine, i just wanted to replace it because it was noisy.

At the same time, i wanted to add a new light during my bath remodel. So I wanted to put two "appliances" on a single gang double switch.

The fan had to have power somehow... so i looked up in the ceiling and there was a junction box there. It fed the fan in one direction, (which i tied black white stripe to black and white to white) and a separate wire from the junction box ran down the wall to the wall switch.

That wire had a white and a black/white stripe (it is not modern day romex, so no ground).

Hooked it up and it worked. Essentially a plug and play replacement

i then ran romex from the new light down the wall. So i have yellow romex with a white, black , and ground. I need to get power to that light and to the wall switch.

it seems like there should be an easy way to tie the fan power to the switch, and then the switch to the light.

You guys are way too patient. My neighbor has promised to help me, but I want to learn and understand the concepts..thus my fight onward.

i have the ceiling buttoned up. However the wall is open and i can see another romex that can be tapped into if necessary. it feeds another wall switch (a three way) for purposes of this argument this paragraph should probably be deleted to avoid confusion

jwelectric
08-06-2007, 11:52 AM
The fan had to have power somehow... so i looked up in the ceiling and there was a junction box there. It fed the fan in one direction, (which i tied black white stripe to black and white to white) and a separate wire from the junction box ran down the wall to the wall switch.

That wire had a white and a black/white stripe (it is not modern day romex, so no ground).

Hooked it up and it worked. Essentially a plug and play replacement

In the junction box you have the supply from the panel. The white from the supply in this junction box is connected to the white that goes to the fan. The black from the supply is connected to one of the conductors going to the switch and the other conductor from the switch is connected to the black going to the fan.

Does this sound right?

If I am right then the two conductor coming from the junction box to the switch will need to be replaces with a three conductor in order to get the two lights to work from the stacked switch and the two conductor cable from the new light needs to go to the junction box.


i then ran romex from the new light down the wall. So i have yellow romex with a white, black , and ground. I need to get power to that light and to the wall switch.

it seems like there should be an easy way to tie the fan power to the switch, and then the switch to the light.

Here is where you are going wrong. If there is only two conductors coming from the junction box to the switch then the switch does not have the grounded (neutral) conductor that would be required for the light to operate. The cable for the light MUST go to the junction box in order to tie into the grounded (neutral) conductor there.

The switch would then need three conductors as follows, one to supply current to the switch and one conductor for the fan and another to supply the light.

Think of this circuit like this; current is supplied from the black wire and MUST return through the white wire. The supply (black) wire and the return (white) wire from the panel is in the junction box. As it was originally installed the current came into the junction box down to the switch back to the junction box to the fan returning on the white wire to the junction box and then to the panel.
To add another fixture to this circuit we MUST have the return (white) path and a supply (black or any other color) for the new fixture.
From the junction box we connect both the fan and light return (white) wires to the return (white) wire going back to the panel. Then send the current down to the stacked (two) switches (if using three conductor NM cable the white conductor with a color tape at each end to reidentify it as other than white) wire through each switch back to the junction box through the black and red wire to the fan and light by way of the black wire to each.

Now we have current coming into the junction box going down to the switch and back to the fan (black) and the new light (red) through each back to the junction box through the white where they both can return on the white in the supply.

lee polowczuk
08-06-2007, 01:13 PM
In the junction box you have the supply from the panel. The white from the supply in this junction box is connected to the white that goes to the fan. The black from the supply is connected to one of the conductors going to the switch and the other conductor from the switch is connected to the black going to the fan.

Does this sound right?

Yes, this sounds right

If I am right then the two conductor coming from the junction box to the switch will need to be replaces with a three conductor in order to get the two lights to work from the stacked switch and the two conductor cable from the new light needs to go to the junction box.

I am beginning to understand... but the junction box could now be a PIA to get to...

I will have to think this through a bit....

You guys are worth your weight in gold.. i can do plumbing and auto mechanics (non electrical), but electricity really throws me.

i am also wiring for a whirlpool tub and heater...but those on are dedicated GFCI circuits..and i will have an electrician (i always planned for this) hook it up to the basement panel..

i'll keep you posted on the eventual solution.

Mikey
08-06-2007, 01:55 PM
Bottom line is you've got to understand the notion of a "circuit". There's a reason that a battery has two contacts on it, a receptacle has two outlet holes (plus the 3rd -- a ground -- which we can ignore for this discussion), and two wires come from the panel. In all these cases, one wire (the "hot" wire) can be thought of as the source of the electricity, but you can't actually "use" electricity without returning the "used" electricity to the other contact, wire, hole, etc.

The way you've wired the light, if I understand it, is you've got two wires going to it, but both of these wires come from the source -- ultimately the black wire from the panel. One side of the light has to be connected to the return side -- the white wire from the panel.

Moral: never close up your work until it works.

jadnashua
08-06-2007, 03:03 PM
Let me try again.

WIth the cable that comes from the power panel, when it gets into the box where the fan is now do this:
- add a new 2-wire cable: connect it to the incoming wire from the panel: black to black, white to white, and connect the ground wire (since you don't have one coming from the panel) to the box.
- run this wire to the new light fixture's box.
- connect the white wire to the light's white wire, and the ground to the box.
- take the wire you ran to the switch, and connect it's white wire to the black on the lamp and the black to the black of the two cables.

Mentally, now, follow the power - from the power panel the hot wire gets jumpered and runs down to your new switch. WHen you close the switch, it runs back up to the hot side of the lamp (it's black wire). Through the lamp, to the white wire that goes back to the power panel through the jumpers between the two boxes.

jwelectric
08-06-2007, 05:04 PM
I am beginning to understand... but the junction box could now be a PIA to get to...

All juction boxes are required to be;
Accessible (as applied to wiring methods). Capable of being removed or exposed without damaging the building structure or finish or not permanently closed in by the structure or finish of the building.

lee polowczuk
08-07-2007, 06:11 AM
I just have to pull out the fan and box is there.

Mikey
08-07-2007, 01:02 PM
I suspect that even though the box is "accessible" as required, it now ain't so easy to get another wire into as it used to be. Lee, welcome to the wild and wonderful world of wire-fishing! All you've really got to do is get a single wire from the fan, to either the switch or the light -- child's play.

frenchie
08-07-2007, 02:03 PM
Mike - you keep forgetting that I always take your side on those debates. Read Verdeboy's thread.


Lee - keep bugging us. It's when you don't ask more questions, that I get nervous.

(did he misunderstand? Is the reason we haven't heard from him, that he's getting electrocuted?)



If it helps - this is wildly innacurate, but works for me - I picture electricity as a closed water system, like a hydronic heating system.

The switches are valves. Any load (the fan, the light, etc) is a little water wheel that turns when the water runs through.

The main panel is a pump, it only circulates water through the lines. Every circuit must return to the source if it's going to work.

Any dead ends, water can't move.

Black wire (before the load) is under positive pressure, getting pushed by the pump; white wire is under negative pressure, getting sucked by the pump.

Like I said, it's wildly innacurate, but it helps clarify these kinds of problems.

The light/switch circuit has a pipe coming into it, supplying pressure; but it only loops back on itself, there's no return line back to the pump. The whole circuit is basically a dead end.

You need to add a line going back to the source.

Hope it helps, rather than confusing you worse.



If that doesn't, check this drawing:

lee polowczuk
08-07-2007, 02:19 PM
frenchie... that's the best picture yet.... and great explanation, too..

I does seem like the single wire has to go back to the fan, since it has the power source.
fishing a single wire shouldn't be too difficult.. the bathroom is only 6 feet wide and the fan is centered in the ceiling... the wall for the most part is opened up.

Monday, Tuesday, and Friday are my busy days at the day job..

also, my son's car was running hot... and he needs a new fan clutch... now basic mechanics i understand.

i am monitoring the boards and really appreciate you guys.

i promise i'll keep you posted of my progress

lee polowczuk
08-11-2007, 02:56 PM
My next door neighbor came over today.

Rather than fishing a wire through the ceiling... he took another approach.

This switch was in a double box with another switch... he ran power from there and tied everything together... did the neutral...and ground.

it all works great.

He does suggest that i get a deeper double box. all of the wires are pretty crammed in there..

the older wire (pre-romex) takes up a lot of space.

it is amazing to see someone draw it out on paper and execute.

i finally did understand what everyone was saying... i just couldn't execute.

thanks everyone...

i have to wire two separate gfci connections for the hot tub... but i will have the electrician hook them up to the box.

lee

Mikey
08-12-2007, 06:50 AM
This switch was in a double box with another switch...

NOW you tell us...

lee polowczuk
08-12-2007, 09:34 AM
I am sorry, man... i just didn't even think that you could tie in that way...

a lot of things make much more sense now... a strong lesson learned.

and i do really appreciate everyone's effort