uf feeder / detached garage

[Kdog76]

Looked at a job the other day to wire up a detached garage. HO wanted an underground circuit ran out to the garage, in addition he requested a 3-way switch between the garage and house. My first thought was running a 3 conductor UF cable, but to get a 110 volt circuit and a 3-way out there - (and this is about 75' out) am thinking about running 2 2 conductor UF's (probably 12-2). One for feed & neutral, and the other 12-2 UF for travellers. Normally I would run a 3 conductor between the two 3-way switches, but do to the length here, I thought about running 2 2 conductors. See any problems with this idea?

 

[480sparky]

75' is too far?

Run a 12-2 UF for power, and a 14-3 UF for a light.

 

[Kdog76]

Thanks for the reply.
In our location, if we run more then one circuit out to a detached garage we are required to install 2 supplemental grounding electrodes. I had planned on keeping this all on one 20 amp circuit. If I have my feed inside the house, and the switch leg is in the garage (outside light by the service door), I could get away with 2 12-2 UF's to make my 3-way work. Is it a code violation to run a 12-2 for my travellers, and a 12-2 for the feed?. In fact, my old employer would run a 2 conductor between two 3-way switches when the feed was on one end, and the switch leg on the other end, as in this example. I thought it was an NEC violation, but never found it in the code...

 

[Rewire]

Thanks for the reply.
In our location, if we run more then one circuit out to a detached garage we are required to install 2 supplemental grounding electrodes. I had planned on keeping this all on one 20 amp circuit. If I have my feed inside the house, and the switch leg is in the garage (outside light by the service door), I could get away with 2 12-2 UF's to make my 3-way work. Is it a code violation to run a 12-2 for my travellers, and a 12-2 for the feed?. In fact, my old employer would run a 2 conductor between two 3-way switches when the feed was on one end, and the switch leg on the other end, as in this example. I thought it was an NEC violation, but never found it in the code...

somebody will give the reference but it has to do with running the grounded conductor with the ungrounded conductors

 

[satcom]

Thanks for the reply.
In our location, if we run more then one circuit out to a detached garage we are required to install 2 supplemental grounding electrodes. I had planned on keeping this all on one 20 amp circuit. If I have my feed inside the house, and the switch leg is in the garage (outside light by the service door), I could get away with 2 12-2 UF's to make my 3-way work. Is it a code violation to run a 12-2 for my travellers, and a 12-2 for the feed?. In fact, my old employer would run a 2 conductor between two 3-way switches when the feed was on one end, and the switch leg on the other end, as in this example. I thought it was an NEC violation, but never found it in the code...

Your right when you run more then one circuit rules change, I don't have the quote in front of me but I am sure othere will come in here, and quote it, but try running 10-2 UF and controlling the light with X10 control, I had this working on one of my garages for the past 35 years with no problem, I can even turn on the light from the car as i approach the garage.

 

[Kdog76]

Your right when you run more then one circuit rules change, I don't have the quote in front of me but I am sure othere will come in here, and quote it, but try running 10-2 UF and controlling the light with X10 control, I had this working on one of my garages for the past 35 years with no problem, I can even turn on the light from the car as i approach the garage.

Suggesting a 10-2 for the voltage drop? Good point.
As far as running grounded with ungrounded conductors, I am still not sure where to draw the line... I won't do it in any metal conduit - but as far as NM or UF cable, I use 2 conductor all the time for a backfed switch...And as far as 3-ways - You got a common (feed or switch leg) and two travellers (no ungrounded conductor in that case either)

 

[wbalsam1]

All conductors of the circuit must be contained within the same cable. See 300.3(B). :smile:

 

[Kdog76]

All conductors of the circuit must be contained within the same cable. See 300.3(B). :smile:

" all conductors of the same circuit, and WHERE USED, the grounded conductor and all EGC's and bonding conductors shall be contained in the same raceway,..etc. "

I am interested in what others think of this topic - esp. in regards to a backfed switch using a 2-conductor. (Which I believe the NEC allows- provided you mark the white conductor as ungrounded conductor)

 

[480sparky]

Forget UF. Run PVC & THWN UG.

(Looks like I am IMing!)

 

[augie47]

spunds like an ideal situation for a low-voltage lighting relay or a "wireless" lighting contol.

 

[wbalsam1]

" all conductors of the same circuit, and WHERE USED, the grounded conductor and all EGC's and bonding conductors shall be contained in the same raceway,..etc. "

I am interested in what others think of this topic - esp. in regards to a backfed switch using a 2-conductor. (Which I believe the NEC allows- provided you mark the white conductor as ungrounded conductor)

........but to get a 110 volt circuit and a 3-way out there - (and this is about 75' out) am thinking about running 2 2 conductor UF's (probably 12-2). One for feed & neutral, and the other 12-2 UF for travellers......

Your quote above is why I posted 300.3(B). You would not be permitted to have the travellers in a different cable... Also, does what you are doing comply with 225.30? I may not understand...just asking. :-?:smile:

 

[nakulak]

spunds like an ideal situation for a low-voltage lighting relay or a "wireless" lighting contol.

who is spunds ? Is he an expert on this subject ?

 

[Kdog76]

Your quote above is why I posted 300.3(B). You would not be permitted to have the travellers in a different cable... Also, does what you are doing comply with 225.30? I may not understand...just asking. :-?:smile:

I will be in compliance with 225.30 IF I keep it all on one circuit (which I am planning). Consensus seems to be that no I cannot run my travellers with a seperate 12-2 UF. I like the idea of UF because of the labor savings...And yes, looks like I'll be running a 12-2 and 12-3 together, all on the same circuit. Thanks again for all the input here, kinda confirmed what I thought all along...

 

[Dennis Alwon]

I will be in compliance with 225.30 IF I keep it all on one circuit (which I am planning). Consensus seems to be that no I cannot run my travellers with a seperate 12-2 UF. I like the idea of UF because of the labor savings...And yes, looks like I'll be running a 12-2 and 12-3 together, all on the same circuit. Thanks again for all the input here, kinda confirmed what I thought all along...

I believe what he wants to do is to feed the garage with a 2 wire circuit and run another 2 wire cable for the travellers to a 3 way switch fed from the same circuit as the wire feeding the garage.

This hookup would be legal based on 300.3(B)(3) however it will create unwanted EMF's. I would not recommend this. Either run PVC and pull the extra wire or run a 12/3 or 14/3 for the 3 ways.

 

[LarryFine]

" all conductors of the same circuit, and WHERE USED, the grounded conductor and all EGC's and bonding conductors shall be contained in the same raceway,..etc. "

This is a case of "you gotta finish reading the section." There is no problem with using two 2-conductor cables as if it was a single 4-conductor cable.

As long as the travelers are kept parallel with the neutral, there's no problem with EMF's. Just keep the two cables together from box to box.

I am interested in what others think of this topic - esp. in regards to a backfed switch using a 2-conductor. (Which I believe the NEC allows- provided you mark the white conductor as ungrounded conductor)

So far, I say two cables is okay. Can you explain what you mean here? What would be the back-fed switch?

 

[Kdog76]

So far, I say two cables is okay. Can you explain what you mean here? What would be the back-fed switch?

The example I had in mind would be where the feed comes to light first (ungrounded & grounded conductor), and where the switch leg is a 2-conductor going from a light down to a single pole switch (ungrounded leg & switch leg - no neutral going down to the switch). In that case where the switch is off - you have only side hot, and when the switch is on it energizes the other conductor of the two conductor cable. (again no neutral here)... I've seen it done before. I'm not sure how code treats it - other then possibly a violation of 300.3 (B).

 

[satcom]

What do you see wrong with using the 10-2 UF and controlling the lights with X10?

 

[Kdog76]

What do you see wrong with using the 10-2 UF and controlling the lights with X10?

Other then I'm not to familiar with the X10 set-up, although I understand what it does. I've got another job where we're planning on using the simply-automated line of products. www.simply-automated.com. Expensive switches, but they seem to fit the application (3-way switching over 100' away & not to easy to install wiring between the two switch locations)...
Any info on the x10 would be appreciated.

 

[satcom]

Other then I'm not to familiar with the X10 set-up, although I understand what it does. I've got another job where we're planning on using the simply-automated line of products. www.simply-automated.com. Expensive switches, but they seem to fit the application (3-way switching over 100' away & not to easy to install wiring between the two switch locations)...
Any info on the x10 would be appreciated.

Don't forget with X10 there is no need for expensive anything, no need for three ways, one mod for the light with the same code, and as many $7 switches as you need. we have been doing this for years, and coustomers love it, they can buy additional mods, and hav all kinds of features, added at budget prices. We can beat most anyone on price, to do a detached garage with lights. http://www.x10.com/catalog/cat_automation.htm

 

[Dennis Alwon]

The example I had in mind would be where the feed comes to light first (ungrounded & grounded conductor), and where the switch leg is a 2-conductor going from a light down to a single pole switch (ungrounded leg & switch leg - no neutral going down to the switch). In that case where the switch is off - you have only side hot, and when the switch is on it energizes the other conductor of the two conductor cable. (again no neutral here)... I've seen it done before. I'm not sure how code treats it - other then possibly a violation of 300.3 (B).

I see nothing wrong with this example and it is not a violation of 300.3(B). Think of the switch leg as just being a little longer than the neutral.