Hey, thanks in advance for the knowledge.
Two questions:
1. I have a three way that I replaced a switch on and now it only works as two separate switches, I have to turn it off where I turned it on. Is it as simple as swapping a couple of wires on the replaced switch?
2. I'm drawing an electrical plan for a home. I know I need three way switches at each end of a hallway. At some point a hallway becomes short enough to be controlled by one switch, what is that length? Is is code defined? Rule of thumb?

Thank you.

1. Are you sure you replaced the switch with a 3-way switch? If you did, they you switched two of the wires.

One wire in a 3-way switch is "unique". It either provides line voltage or it goes to the lamp. The other two wires run between the two three-way switches (I call them "travelers". I'm sure there are other names). Disconnect the switch. Using a voltmeter, measure the voltage on the three wires. Is one of those wires "live" (120V)? If so, toggle the other switch (the switch that is still wired in) and see if the live wire switches to another wire. If it does, then those two wires are the "travelers". If it does not, then the wire is the "unique" wire.

2. I'll have to defer to a code expert.

There is only one requirement in the NEC for light switches in a residential hallway.

NEC 210.70(A)(2)(a) requires one wall switch operated lighting outlet in every hallway.

So no, it isn't defined in the NEC but there may be a code for it elsewhere. I've always just used my best judgment and it's never been a problem.

Tev,

Check the NEC again. I believe that there are additional codes for hallways. I don't have my code book with me today but I believe that if a hallway is less than 10 ft. long, no light is required. Greater than 10 ft. requires a light. I also believe that the light must be controlled from both ends of the hallway. I'll check the NEC when I get home this evening.

Thanks guys,

That's what I'm wondering about the 10' part, lets say my hallway is only 8' long, do I still need a switch at both ends. If the code says I don't need a light at all I guess I don't need any switches. Thanks for checking. I'll await a final code response. I appreciate your feedback guys.

D.

Dieter,

For my opinion, I would always control a hallway light from both ends of the hallway. It makes no sense to place the control on one switch.

Don, the 10 foot rule is for a hallway receptacle outlet. A lighting outlet is always required in a hallway.

For the most part, it's a good idea to switch at both ends. Otherwise you end up walking to the halfway point and then turning on the light only to turn it right back off because it's the only switch. On the other hand, a 3 foot hallway doesn't really need two switches.

The code reference is NEC 210.70(A)(2)(a) for the lighting. 210.52(H) is where the receptacle outlet rule is located.

Thanks All.

I'll use the common sense rule and maybe if its farther than two steps I'll put the second switch.

Thanks again.

I'll go fuss with that three way switch now.

D.