Trouble with a double switch
mick_meyers
| Posted in Energy, Heating & Insulation on
Hello everyone…. i’m helping a friend wire an old kitchen. The trouble I’m having is with a double switch. There are two sources of power coming into the box, with one switch turning on the garbage disposal. The old switch (which was taken out by her) has four screws on one side, and three on the other. Also looks like the tab has been broken off. Again there are three (14/2) cables coming in, two have power (on their own circuits) and one goes out to the garbage disposal. Could someone help me with this…. i’m wondering if maybe i shouldn’t disconnect one of the powered cables.
Mick
Replies
I've re-wired a lot of old houses but have never seen a switch that resembles the one you describe so I can't be much help on that score. Try taking it in to your local electrical supply store and see what they make of it. You'll need to buy a comparable switch to replace it, anyway, and you're not going to find anything like that at Home Depot....
I have also never seen two separate live circuits coming into the same switch. What you likely have facing you is (1) power-in, (2) switched power- out to the garbage disposal, and (3) unswitched power-out going on to other switches or outlets on the same circuit.
If you're at all unsure about this, you should call in a real sparky; it's not possible for any of us to diagnose this kind of problem safely without seeing it.
Dinosaur
How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....
I believe that he is talking about a 2 switch combo.http://www.amazon.com/gp/product/B00002NAPL.
William the Geezer, the sequel to Billy the Kid - Shoe
how about a combo/double 3way? wiring config would be interesting. maybe a shared neutral? somehow I can't make it work in my head, but I "think" it will.
http://www.amazon.com/Leviton-031-05243-00I-15-Amp-125-Volt-Combination/dp/B001JYWYIM/ref=sr_1_3?ie=UTF8&qid=1242401589&sr=1-3
And with 3-ways there are many different ways that each can be wired.Lets see with one 1/2 we could have power comming in and the fixture connected and the cable to the other 3-way.On the 2nd one we could have a shared neutral circuit coming in to power it and a 3-1 cable (yes they are available, but not common) continuing the shared neutral, the travelers and the hot from the other half of the shared circuit. The only problem with this is it would take a 4 gange box to get enough wiring space for all of this..
William the Geezer, the sequel to Billy the Kid - Shoe
I only mentioned this becasue he said 4 screws on one side and 3 on the other, ground screw included on the side with 3 screws? Or a combo 3way and outlet?
to me, it sounds more like they used a switch like I mentioned for just common combo switch. As for the #wires in the box, I'd need to look. I don't remember how many #12's or #14's in abox. Shallow or deep box?
can't see it from my house...
It does.I had to go back and reread it.I could have sworn that he said 5 screws.So it sounds like it might have been 3-way switches that where used.But he only has 3 14-2 cables so both of them could not have been used as two 3 ways. But one section might have been used to switch power from the DW to the GD when you want to run the GD. Not a standard applications, but something that might have been done.But that leaves the other 1/2 unused and does not explain the 2 cables being "hot".Or it might have been 2 California 3 ways or using the ground for a 3rd conductor. But both of those are not legal..
William the Geezer, the sequel to Billy the Kid - Shoe
It's hard to say without more detail; a pic would help. It sounds like a double pole single throw switch, i.e. for switching a 240 volt load (or two 120 volt loads). But why is it in a kitchen? I dunno....
I guess the other possibility is a DPDT switch, which can be used for reversing motors.....but that wouldn't usually involve all those wires.
Scott.
>>i'm helping a friend wire an old kitchen.<< There are potentially a lot of goofs present - this switch and box may well be one of them.
I would concern myself with "what you need" rather than "what was there".
"One goes out to the garbage disposal." - that sounds like a need.
"Two have power (on their own circuits)." - one of these is needed for sure.
Old switch configuration is academic --- get the switch you need -- sounds like a garden variety single pole switch is what is required.
If both of the 14/2 powered cables are dedicated circuits, i.e., garbage disposer is the only thing powered by the circuit. I would just disconnect one of the circuits at the SEP and cap the cable in the switch box. This configuration is doubtful
If not dedicated circuit, what else does not work? Could be obscure / removed - lights in an upstairs bedroom, outlets in a hallway, etc.
If all else works properly, I would find the source of the power for the second cable, probably a nearby switch / outlet box and disconnect and cap it there also.
My point is that before you remove either of the powered cables from service you need to know where it comes from, once you know that, you can make a rational judgement which cable to leave in service.
Old work can be a detective job, be patient, good luck.
Jim
can you post a pic of these screw configurations???
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
My guess is that you have one circuit bringing in power and switch power out to the garbage disposal.
The other cable is a Switch Leg for the over the sink light.
With the tab broken you basically have 2 independent switch.
This is not that uncommon wiring for a kitchen, but usually uses a 2 gang box and 2 separate switches.
This is how switch legs are wired.
http://www.selfhelpandmore.com/switch-outlet/basic-light-switch/single-switch-power-source-at-fixture.php
Note that this really not a "hot circuit" in that you can't connect a load to it. But it might test hot. If you don't remember which is which remove the bulb from the light. Any 2 wire contact tester then will show that it is dead. But the unswitched hot will still be hot if you measure between it and another neutral and ground.
Note that the white is suppose to be the unswitched hot and it is suppose to be marked with tape or paint to a color other than white, gray, or green. But this was often not done correctly and the code did not always require the remarking.
Each 1/2 switch, with the tab broken, connects like any other basic switch. In this case you use the top terminals on each side for one and the bottom for the other. And the green is for a ground wire if one is there.
William the Geezer, the sequel to Billy the Kid - Shoe
First, we need to get it clear: Is this two switches on one yoke -- the two switches fit in place of a single duplex receptacle -- or two separate switches??
If it is two switches on one yoke then you need to be aware that some replacement switches may have only 3 terminals, on the assumption that a common line will feed both switches.
The number of screws you describe is confusing -- sounds like it may be two 3-way switches. This would be very unusual for a double switch, and you may have trouble finding a replacement (if indeed you need a 3-way replacement).
From the cabling you describe I'd guess that you have one cable with power coming from the breaker panel -- this is to power the disposal. Then you have another cable coming as a switch leg from a light. If all of the cables are 2-wire (plus ground) then the switch leg would not be a 3-way and you shouldn't need 3-way switches.
Describe which wires are loose, if the HO didn't completely disconnect things. I'd guess that two of the three whites are wire-nutted together, right? If so, those two cables would be the power feed and disposal, and you'd connect one switch between their two blacks.
Then the other switch would PRESUMABLY be a switch leg for a light (is there a light purportedly controlled by this switch??). You'd connect the other switch between the white and black of that cable.
Unfortunately, if there is a mis-guess somewhere, connecting the black and white will create a dead short, with resulting fireworks. So you want to be kinda sure on this point.
As one of the other posters said, don't worry about what kind of switch was there before, just install what is needed.
I like Bill's suggestion that one hot cable is power for the GD and the other is actually a switch leg for a light.
If so, you should find the white wires from two 14-2 cables wire-nutted together. Those would be the GD circuit cables.
The hot black should go to one hot post (black or brass screw) on a replacement two-pole combo switch and the black from the other (outgoing to GD) cable to the chrome screw terminal opposite.
The third Romex cable probably has both the black and white wires looped at the ends where they had been wrapped around the screw posts. These would have been the switch leg of the light. Wire the "hot" one to the black or brass screw for the other switch and the white one to the chrome screw opposite.
Be sure to break the tab between the two black or brass screw terminals.
When you restore power you should have a functioning GD switch and a light switch
Thanks everyone for the advice... i'll post a picture tomorrow of the deadly double switch...
Your old double switch controlled 1) the garbage disposer and 2)___________.
With this switch removed what does not work? We need to know to be of any real help.
Early on in this thread, BillHartmann guessed that the second switch was a switch leg for an oversink light.
His speculation has been adopted as fact among the posters, but never confirmed.
This was excellent speculation since that configuration would explain the presence of 2 hot cables - supply line in + a switch leg being powered out of the lighting fixture / box.
If this is indeed the case, you just need to recode the white wire in the switch leg and connect to a new double switch; snap out the tab on the supply side; connect line in to garbage disposer on the other half of the double switch.
JimNever underestimate the value of a sharp pencil or good light.
Here are some pictures of the switch... and again thanks everyone.mick
To me, that looks very much like a pair of two-pole switches, designed to fit in a single-gang workbox. And two-pole switches require three wires to be connected to each switch.You have a pair, hence six terminals for wires. The (now removed) tab between two of those terminals allows two separate double-switch circuits to be powered from the same power-supply wire -- effectively reducing the required connections to five.When a room has two entrances, and a ceiling light, there is a light switch at each entrance to the room. Either switch can be used to turn the light on or off, regardless of the position of the other switch.That type of circuit requires two-pole switches. Your garbage disposal does not, since it is controlled by a single switch.One of the bigger questions needs to be..... was there actually a wire connected to each and every terminal on the old switch?Another would be.....were there two devices being controlled -- one by the top switch of the pair, another by the other?........ let us know, answers can follow.
Politics is the antithesis of problem solving.
>>When a room has two entrances, and a ceiling light, there is a light switch at each entrance to the room. Either switch can be used to turn the light on or off, regardless of the position of the other switch.
That type of circuit requires two-pole switches.<<
Funny, I always thought the switch required for the above situation was called a 3-way switch, at least that's how the boxes, shelf tags and wiring diagrams are labeled here, must be a local thing.......
I believe a two-pole switch is for switching 2 hot leads simultaneously like a for a 240v motor perhaps.
JimNever underestimate the value of a sharp pencil or good light.
And you would be correct. That picture just looks like to single pole switches caddied together. I would guess that the copper color terminal is the hot-leg.
Poster, take a picture of the box, and we will sort this out once and for all. You do have a multi-meter, don't you?
Dude -- look at both pictures. Each switch has two terminals on one side, plus a third terminal on the opposite side.And yes, I screwed up on the correct name. My apologies.But I still believe that he has a double three way switch.
Politics is the antithesis of problem solving.
Right, and the center terminal on the side with two screws still in place was the ground lug.
BruceT
Technically, it's not a two-pole switch, it's a single-pole/double-throw (SPDT). (Doubled, of course -- two separate switches). This is what's commonly referred to as a "3-way" switch, for hysterical reasons.
The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
1) I have never seen a double switch like that.
2) My guess as to what it is: I suspect that is a double, 3-way switch.
The side with three screws = 1 traveler connection for each of the two switches + the switch grounding wire connection screw in the middle.
Other side with the tab snapped out and 4 screws = 1 common wire connection screw + 1 traveler wire connection screw for each of two switches. 2+2=4.
It appears that this switch would allow supplying power to two, three-way circuits via one "line in", if you did not remove the snap out tab.
I don't think you need to replace this with a switch of the same configuration as your old one, a double single pole would probably be just fine - easy to get - even the big boxes have them.
We still don't know what this combo switch used to power -- garbage disposer and ___________________. Once that is known, you can determine what switch you actually need. We can help.
JimNever underestimate the value of a sharp pencil or good light.
Yep, it appears to be a double 3-way switch. Were there wires on the terminals with the screws still in them? I'm guessing not.
The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
Looking at it it appears to be a dual 3-way switches. If this is an single throw switch, whether single for 2 pole, the handle with be marked On/Off. If it is a 3-way there won't be any markings on the hand.ethe the 2 copper colored terminals are the commons and that there was a bridge between then that was broken out. And from the scratch marks it like like wires might have been connected to them.From the paint on the other side it looks like these have not been used, but not sure. But I don't see any markers one the first side that looks like it was either.But if these are 3-ways being used as single pole switches then it the only difference that it makes is that if the switch is on when you move it to the left or to the right. And you can also change that by flipping the switch around.Now you did not answer the questions about if the you have the neutrals on 2 of the 14-2 connected and the other 14-2 both lead where on a terminal. If if the wire nut has been removed on the 2 neutrals then it should still be able to tell as those will have a twist in them. All of the other wires will have loops in them from being around the screw.And does the other switch control the light over the sink? Or it might be some under the cabinet lights and even the main light..
William the Geezer, the sequel to Billy the Kid - Shoe
You seem to be missing a wire. My guess would be that power first goes to the disposal receptacle than to the switch. The other hot may then be for powering the sink light. If the two hots were constants you'd need two loads, but you only have three wires. Best way to prove this would be to open up the light box and the disposal recp box and see how they're wired.
Family.....They're always there when they need you.
Soooooo, how did this all work out for you?
Jim