A friend of mine has two switches, one for garbage disposal and one for light above sink on the same circuit but opposite sides of the sink. About a year ago, both switches stopped working but the breaker didn't trip. I tested continuity on both switches and they were both bad. I replaced them with new Leviton switches. Just got a phone call that the same 2 switches stopped working. I'm guessing the disposal might have something to do with it. Has anyone else run into this?
Same 2 switches keep going out
- Thread starter marshak
- Start date
Jim greengo
Well-known member
Tell him to quit beating on them so hard
sberry
Banned
Loose connection feeding them.
jeffmattero76
Well-known member
- Joined
- Mar 26, 2018
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Have you or he checked continuity on these two switches?
As the previous poster stated, my bet would be on a loose connection, possibly in the Junction box before these two switches, or in the Junction box where the first switch is located.
May I ask how you checked for continuity on the old bad switches?
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As the previous poster stated, my bet would be on a loose connection, possibly in the Junction box before these two switches, or in the Junction box where the first switch is located.
May I ask how you checked for continuity on the old bad switches?
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ripperd
Well-known member
Are they operating them with wet hands or splashing water on them, causing corrosion?
wyliesdiesels
Well-known member
Pretty rare for switches to go out without outside influence.
Lightman 1
Active member
If the switch is indeed failing and its not another problem I would try a better quality switch. Most manufactures offer several different grade devices and the big box stores often stock the cheapest.
Lassen Forge
Well-known member
WAGs... Reversed leads, so the switch is always hot, and it's switching the neutral? The disposal is a commercial model and draws more amps than the switch is rated for on start-up, and somehow surges the current in the circuit?
ripperd
Well-known member
No, actually pretty unlikely. Tap water is not going to support 15-20amps to trip the breaker. a GFCI might trip, but that's assuming the ground is connected properly to the switch frame.
Duck tape Bill
Well-known member
He's had four switches go bad... the two original ones, and the ones you put in. It sounds like a wiring issue to me.. but..
We need to know:
- what amperage is the breaker feeding the circuit?
- what is the amperage ratting of the switches (do you have 15amp switches on a 20amp circuit)
- what's the amp rating of that disposal?
- a simple wire diagram might also help
If it's a 20amp circuit, with 15amp switches, and the disposal pulls over 15amps, then you might burn the switch to the disposal out that way. It seems odd to me that the light switch would be burning out as well, since I can't imaging the light would draw enough amps (assuming the wiring isn't faulty). I guess if the power fed through the light switch, then to the disposal switch it could burn both out.
We need to know:
- what amperage is the breaker feeding the circuit?
- what is the amperage ratting of the switches (do you have 15amp switches on a 20amp circuit)
- what's the amp rating of that disposal?
- a simple wire diagram might also help
If it's a 20amp circuit, with 15amp switches, and the disposal pulls over 15amps, then you might burn the switch to the disposal out that way. It seems odd to me that the light switch would be burning out as well, since I can't imaging the light would draw enough amps (assuming the wiring isn't faulty). I guess if the power fed through the light switch, then to the disposal switch it could burn both out.
Lassen Forge
Well-known member
Maybe the circuit from the light then feeds the disposal? Pulling the amps through the switch? (I've seen some pretty screwey "shortcuts" on house wiring...)
I still think the disposal is pulling more amps than the switch can handle... put a light duty 10-15 amp light switch against a 20+ amp starting current disposal motor, and yeah, that switch son't have much of a chance to make it to old age...
First thing I'd do is chase wiring back to the box, and make sure the disposal is on its own circuit. Then make sure whatever switch you put on that thing is rated for a higher ampacity than the disposal draws under a full load start condition (our old disposal pulled 18 amps if it had **** in it and you flicked it on). Make sure the OTHER switch is on an appropriate circuit, and see if the problem still continues... if so, then it's likely you have a neutral issue.
I still think the disposal is pulling more amps than the switch can handle... put a light duty 10-15 amp light switch against a 20+ amp starting current disposal motor, and yeah, that switch son't have much of a chance to make it to old age...
First thing I'd do is chase wiring back to the box, and make sure the disposal is on its own circuit. Then make sure whatever switch you put on that thing is rated for a higher ampacity than the disposal draws under a full load start condition (our old disposal pulled 18 amps if it had **** in it and you flicked it on). Make sure the OTHER switch is on an appropriate circuit, and see if the problem still continues... if so, then it's likely you have a neutral issue.
rlitman
Well-known member
You may be onto something, but not because of the current draw. High current draw will overheat a switch that's in continuous operation, but nobody runs a disposal all day.
There's a reason that motors should be controlled by switches rated for the appropriate horsepower, and that switch horsepower ratings are not really related to current ratings. The issue is that the spark created when you turn the motor OFF will erode the contacts.
I'd start by replacing the switches with spec-grade switches.
wyliesdiesels
Well-known member
That would have to be a 1+ hp disposal to exceed 15a.
But if the lights are on the same circuit, may be in violation of 210.23(A)(2)
But if the lights are on the same circuit, may be in violation of 210.23(A)(2)
Lightman 1
Active member
Most residential disposals are 1 hp or less. Many are 1/2 or 3/4 hp. That should pull 10 amps or less. Thats enough to eventually wear on a cheap 15 amp switch. The arc from starting and stopping the disposal will eventually erode the contacts in the switch. I would replace that bad switch with a 15 or even 20 amp spec grade switch. The switch controlling the light is another matter. It should last forever. I would replace it with a better switch also.
Jim Greengo makes a good point. Some people are rough on switches. Rather than gently turning them on and off they slap them around, sometimes with whatever object that they are holding.
Jim Greengo makes a good point. Some people are rough on switches. Rather than gently turning them on and off they slap them around, sometimes with whatever object that they are holding.
rlitman
Well-known member
Not so fast. If there is arcing across the motor's switch, that could very well be close enough electrically to the light switch to cause arcing there too.
Thanks again for the replies. I replaced both switches with Leviton 20A Double Pole Spec switches from Home Depot. We'll see if that takes care of it.
I did take the old switches apart. Didn't see any burning or anything like that. Both showed continuity in the "on" position once they were taken out but not while installed. Tried putting them in before installing new ones and no dice. Seems very odd but oh well.
I did take the old switches apart. Didn't see any burning or anything like that. Both showed continuity in the "on" position once they were taken out but not while installed. Tried putting them in before installing new ones and no dice. Seems very odd but oh well.
Jim greengo
Well-known member
American Locomotive
Well-known member
Perhaps the wall box isn't installed correctly, so the switches are getting twisted or bent while installed?
sberry
Banned
Highly unlikely that a household disposal is 1 hp either, 1/3 or lame 1/2. They are designed to go on common 15A circuits with a common switch.
SGKent
Banned
electric motors pull more amperage when the voltage is low. If you are comfortable with electricity because I don't want to see someone electrocuted, check both legs of the house hold voltage with a hair dryer. They pull around 1300 - 1500 watts. If you don't have good voltage when the hair dryer is running you could have problems with corrosion on the drop from the power pole. For example, the refridge comes on and you see the lights dim for a second. Classic example. Problem is that if you see voltages in the house that are say falling then the garbage disposal will pull more amps and burn switches up. It could be just that one circuit too. Remember - where ever there is corrosion there is resistance and where ever there is resistance there is heat. Enough heat makes fire. If you aren't comfortable with checking household voltage most electric companies will do it at the meter / drop into the house for free.
MFolks
Well-known member
"Back stabbed" or wired using the screws on the switches sides?
mnwebb
Well-known member
"Both showed continuity in the "on" position once they were taken out but not while installed."
That is a major clue...but I can't figure out the answer....what type of wall is it, any metal lathe that could somehow be effecting the current? Very strange.
Another thing to do is to connect the old switches to power now that they are out of the wall...you said that they had continuity but when you add electricity does the same thing happen?m If they are good then the wiring between the switches, and the disposal, is the next culprit.
-Wilson
That is a major clue...but I can't figure out the answer....what type of wall is it, any metal lathe that could somehow be effecting the current? Very strange.
Another thing to do is to connect the old switches to power now that they are out of the wall...you said that they had continuity but when you add electricity does the same thing happen?m If they are good then the wiring between the switches, and the disposal, is the next culprit.
-Wilson
AntonLargiader
Well-known member
If it is indeed a switch contact issue with those particular loads, I wonder if some old mercury switches might not suffer the same issue.