The replacement from lowes was same brand (cooper) but looked like different model(3 rd contact on opposit side)

I'm not sure I understand. Does the replacement switch have 3 terminals (not including ground) or 4?

I did the only thing I could think of, reversed the hot and neutral on the switch. Problem solved! But WHY?

Now here's where I get really confused. You should NEVER have a neutral connected to the switch. The switch legs in a 3 or 4 way circuit are called travellers and are ungrounded. I drew a picture of how the switch may have been miswired and it would explain why you would have a problem with the other switch in one particular position but not the other.

View attachment Goofy 3-way.zip

Now the wire colors in the second (i.e. goofed) sketch don't make much sense to my case since it would take a total motorhead to connect two white wires to the switch but electrically, it does match your symptoms.

The only thing that confuses me is that you said the breaker would trip sometimes. In the example I have, it should trip every time the two switches are in the correct positions (switch makes a dead short). And this is when you'd most certainly see the arc.

Jim

 

Are the breakers arc-fault type?

 

The "neutral wire" is more than likely the common traveling leg in the circuit. The original installer probably installed it wrong and you copied his mistake.

 

I'm confused. :laughing:

 

Last edited by jlaw : Today at 08:12 AM. Reason: my post

WHY BOTHER?????

This is truly obnoxious!