Few Questions on 3-way's

[NYHigh]

1) Do you need to have 3way switches in a room with two entrances or is that just personal preference? I'm thinking it is just necessary on stairways and hallways.
2) Is it a violation to install switches over a step on stairs?

3) According to code do you need a smoke and CO detector in a garage? I thought it was one smoke per bedroom and hallway and unfinished basement and one CO per floor including basement.

Thankyou. Any help would be appreciated.

 

[iwire]

1) Do you need to have 3way switches in a room with two entrances or is that just personal preference? I'm thinking it is just necessary on stairways and hallways.

No, there is no NEC section that currently requires 3 or 4 way switches in any location. This applies to stairs as well, you could provide a single pole on each landing but the customer might not like that.

2) Is it a violation to install switches over a step on stairs?

No

3) According to code do you need a smoke and CO detector in a garage? I thought it was one smoke per bedroom and hallway and unfinished basement and one CO per floor including basement.

That is not an NEC issue, that would be a local fire / building code issue.

 

[NYHigh]

Thankyou for the prompt response. Very helpful.

 

[stickboy1375]

1) Do you need to have 3way switches in a room with two entrances or is that just personal preference?

Your not even required to have a single pole by the entrance, the switch can be anywhere, most people would just not like it anywhere else but by the door :grin:

 

[cloudymacleod]

i always thought if the stairs had more than 6 risers, u needed a 3-way switch?

 

[stickboy1375]

i always thought if the stairs had more than 6 risers, u needed a 3-way switch?

3 ways are not required be the NEC. Check out Iwires post #2, or you can read 210.70 (2)(c)

 

[480sparky]

i always thought if the stairs had more than 6 risers, u needed a 3-way switch?

Nope. A SP switch at each level will suffice.

 

[George Stolz]

It should be noted, IMO, a pair of single pole switches energized to supply a single point (such as a light) would constitute a 310.4 violation. You'd have a pair of conductors connected in parallel to the light tht didn't match the restrictions placed upon them.

I mean, you could toss in a relay and get around that, but...

 

[iwire]

George, I never intended to switch the same fixture with multiple SPs.

1 SP switch on each landing supplying the one or more fixtures on that landing.

Like I said, I don't think the customer will like this arrangement.

 

[George Stolz]

George, I never intended to switch the same fixture with multiple SPs.

I hadn't considered that.

 

[480sparky]

I hadn't considered that.

I did, may years ago, come across two SP switches in a stairway, that controlled the same light fixture.

However, each switch controlled only one (of the two bulbs) in the fixture.

Would you consider that legal?

 

[Dave_B]

I did, may years ago, come across two SP switches in a stairway, that controlled the same light fixture.

However, each switch controlled only one (of the two bulbs) in the fixture.

Would you consider that legal?

I have seen motion detectors set up that way. Comming from one direction they light up one bulb in the fixture, come the other way and the other bulb is powered. I thought it was brilliant!

 

[quogueelectric]

I have seen motion detectors set up that way. Comming from one direction they light up one bulb in the fixture, come the other way and the other bulb is powered. I thought it was brilliant!

You learn something new every day.

 

[SiddMartin]

I did, may years ago, come across two SP switches in a stairway, that controlled the same light fixture.

However, each switch controlled only one (of the two bulbs) in the fixture.

Would you consider that legal?

I would say so, it's no different then how you wire a bath fan/light. (Unless the fixture is not capable of splitting the two bulbs without messin up the UL listing)