Switch tripping breaker

[Jbell1033]

First, thanks to anyone who reads through this and offers some advice.
Finishing up a laundry room remodel I installed a new ceiling LED fixture and a new Leviton decora wall switch.
The ceiling light is controlled by two switches; one at the garage door (old switch) and one at the kitchen door (new switch). After installing the ceiling light and the new switch when I threw the 15a breaker back on, it sparked and tripped.
When the old switch is in the up position, the new switch controls the new light. When I toggle the old switch to the down position the circuit breaker trips. I did no work on the old switch, only the ceiling light and new decora switch. I'm stumped. Both new installs were simple three wire. Nothing complicated. Thank, John

 

[Reach4]

How many wires connect to the new switch? Is one of the wires to the new switch white? Did you temporarily disconnect any wires that were connected together (with wire nuts probably) before?

 

[Sponsor]

 

[Jadnashua]

There is no standard on the actual location of the wire connections on a 3-way switch...you have to see how they are labeled, and match things up properly by function. IOW, the order and/or location of the wires may not be the same on the new switch as the old one. Note, it's possible that while the old one may have worked, it may not have been wired per code, either, so who knows what's going on now..

One simple thing that could be the source of your problem is that when you pushed the switch back into the box, you now have the ground wire touching something that gets hot when the switch is in one position. Or, you have a crimped wire with some compromised insulation, or if it uses wire nuts, one of the wires slipped out or was too long and could be shorting something. Sometimes, a very careful visual examination is all it takes to discover what's wrong.

Given that the breaker immediately trips, you may be able to spot where in the box something was grounded by either melted wire(s), scorch marks, in the box, or the body of the switch.

 

[Jbell1033]

How many wires connect to the new switch? Is one of the wires to the new switch white? Did you temporarily disconnect any wires that were connected together (with wire nuts probably) before?

Thanks.
No wires were connected together.
Old toggle (garage door)has a red wire at the top, opposite the ground screw. A black wire at the bottom.
New switch has red wire at bottom, opposite the ground screw. A black wire at the top. (Of course rotating the switch puts the red at the top which is why I mentioned it's opposite the ground) I thought I connected it the same as the old switch I took out.
House was built in 1972.

 

[Jbell1033]

There is no standard on the actual location of the wire connections on a 3-way switch...you have to see how they are labeled, and match things up properly by function. IOW, the order and/or location of the wires may not be the same on the new switch as the old one. Note, it's possible that while the old one may have worked, it may not have been wired per code, either, so who knows what's going on now..

One simple thing that could be the source of your problem is that when you pushed the switch back into the box, you now have the ground wire touching something that gets hot when the switch is in one position. Or, you have a crimped wire with some compromised insulation, or if it uses wire nuts, one of the wires slipped out or was too long and could be shorting something. Sometimes, a very careful visual examination is all it takes to discover what's wrong.

Given that the breaker immediately trips, you may be able to spot where in the box something was grounded by either melted wire(s), scorch marks, in the box, or the body of the switch.

When I toggled the garage switch to down I thought I heard a spark inside the switch.
Aren't my switches two way, on/off?
Boxes that hold the switches are plastic.
Should I change the wire on the new switch to black being opposite the ground screw and the red on the bottom?

 

[Reach4]

A 3-way switch has 3 terminals that are not ground. If you bought a switch that has only two terminals plus a green ground terminal, it is not a 3-way switch. Check the model number of what you bought.

https://store.leviton.com/collections/decora-switches

 

[hj]

You could be feeding the light from TWO DIFFERENT hot legs and when you turn the second switch on it creates a short circuit. From your description, it does not appear the you have the correct switches OR WIRING to do what you want to.

 

[Jbell1033]

You could be feeding the light from TWO DIFFERENT hot legs and when you turn the second switch on it creates a short circuit. From your description, it does not appear the you have the correct switches OR WIRING to do what you want to.

Thank you for your reply. This laundry room light has worked off of two switches since the house was built. I haven't done any new wiring. I'm only trying to swap out the toggle switches with the new Levitron decora models my wife picked out. Are you saying this is an incorrect switch for the job? The switch in the wall on the left is the garage door one, then the new one at the kitchen door and the one I took out. John

 

[Reach4]

Check other side of that Decora switch.

Time 1:53 shows the back of a 3 way switch. Note there are four terminals. Only a bare or green-insulated wire goes to the green screw. If you have neither in your box, the green does not get connected. The black screw connects either to the hot from the breaker box, or the hot on the light fixture. The two brass screws connect through wires to the other switch.

If your switch does not have the 4 screws, it is not the Decora switch that you need for the job.

 

[Jbell1033]

Thanks for the video. There are only three wires in the box at the kitchen door.

 

[Reach4]

Yep, wrong switch.

I think you have a metal box that is grounded. I think that white wire is actually hot. The white wire should not go to the green screw. Your new switch will have nothing hooked to the green screw. You will have to figure out which wire should go to the new black screw.

 

[Jbell1033]

Yep, wrong switch.

I think you have a metal box that is grounded. I think that white wire is actually hot. The white wire should not go to the green screw. Your new switch will have nothing hooked to the green screw. You will have to figure out which wire should go to the new black screw.

I got out my multimeter to check. I disconnected the white wire leaving the red and black as pictured above. With the switch off (no ceiling light) the red wire is 122 v, the black is 0.0, and the disconnected white is 0.0. Flipping the switch to ceiling light on, the red and the black show 122 v and the white is 0.0.
With the garage door switch both red and black show 122 v.

 

[Reach4]

Where are you holding the other meter probe for the voltage readings, the boxes?

I disconnected the white wire leaving the red and black as pictured above. With the switch off (no ceiling light) the red wire is 122 v, the black is 0.0, and the disconnected white is 0.0.

I expect that when you flip the garage switch the other way, the red will go to 0, and either the black wire or the white wire will go to 120 regardless of which way the Decora is flipped.

With the garage door switch both red and black show 122 v.

Your garage switch has three screws. Two of the screws would show either 120 or 0 depending on which way the switch is thrown.

 

[Jbell1033]

Yes, black probe to the metal box, other probe on the screw.
When I flip the garage door switch down the circuit breaker trips.

 

[Reach4]

Yes, black probe to the metal box, other probe on the screw.
When I flip the garage door switch down the circuit breaker trips.

Not when you take that white wire of the green screw, I am pretty sure.

Presuming that, that would imply that the white wire will be one of the ones going to a brass screw on the new switch. I think the red would go to the other. And I think the black would go to the black. I am not sure, but that is currently my best guess. The good news is that when you get your new switch, and don't use the green screw, that you will not trip the breaker, even if the wires to brass, brass, and black are wrong.

 

[Jadnashua]

It would be a messy install if a power carrying conductor (typically that would be white/black/red in a 3-conductor cable) ever to be connected to the ground point. The only thing that should be there is the conductor that is designated as the ground...that might have insulation, but it would be designated with green, not any other color. Even though white (in a typical circuit that would be neutral, but may not be in a three-way light) might be connected to ground at the panel, it DOES carry current in a normal circuit, and cannot be connected to ground elsewhere without problems.

 

[WorthFlorida]

Since your original switch had a white wire connected to a screw terminal, your wiring might be as shown below. If you google three way switch wiring there are many configurations all depending on where the power comes from and where the light is in the configuration.

As told above you have a 2 way switch, not a three way as your replacement. Therefore, the white wire has power on it and it being connected to the ground screw (green wire or bare wire) and the box is grounded, that is where your short occurs.

 

[Jbell1033]

Thank you, everyone. Problem solved with the correct switch. A Leviton 5603, 3-way. Next, on to the tub removal!