Code (and safety) question - outdoor lighting on outbuilding

[Sokoloff]

I know that an outbuilding can only have one AC power feed from the main supply. That will be a 100A, 4 wire feeder to a subpanel.

Q1. If I also want the outbuilding to have outdoor spotlights, controlled by switches in the main house such that the outdoor lights on both buildings come on together, can I address this legally by having switched 120VAC lines coming from the house to the outbuilding? (Think "in the era before smart switches, how'd we do this?") If so, what are the restrictions? Can they be in the same conduit as the feeder (assuming fill requirements are observed)? Can they be in the same conduit inside the outbuilding as sub-panel fed circuits?

Q2. Suppose in addition to Q1 situation, I want to have a local override for the outbuilding lights. Do these situations change anything or cause addition commentary/warnings?
Q2a. A three-way switch controlling the outbuilding lights either with or opposite the main house spotlights, (with the power always coming from house).
Q2b. A cut-off switch, meaning a single-throw switch that allows the lights to follow the main house spotlights or be always off.
Q2c. An over-ride switch, meaning a double-throw switch that allows the lights to follow the main house spotlights or be always on.

Thanks!

 

[Sokoloff]

(I may very well end up doing this with smart switches in the outbuilding, which obviously conforms to code, but I'm interested in a simpler possibility if it's legal.)

 

[klassenl]

If you would get power for the lights from the outbuilding that should meet the intent of the rules. The other option would be some form of low voltage switching that would include at least one relay.

 

[AntonLargiader]

It's allowed to have the power from the building come back to the house for the switch. There are restrictions on this, though. Generally limited to one such circuit. It's in NEC 225.30.

I do this with smart switches and IMO there is no comparison as smart switches give you so much more flexibility. Want the light to come on as you drive up? Smart switch yes, switch loop to house no. Want the light to go on when something else goes on? Etc.

 

[larry4406]

Following along as I need to do this as well.

My plan is to feed the lighting circuit from the panel in the detached barn.

Interested in the smart switch approach as well.

 

[ard]

How is this a 'safety issue'? Other than someone turns off the main breaker in the building and there may be an energized switch?

 

[Sokoloff]

Exactly. I assume that's the reason for the "only one feeder circuit to detached building" rule.

When I wrote the subject line, I meant to imply that I was worried about meeting code *and* being safe, which are generally well synchronized. Perhaps I should have just left it as "code question" in retrospect.

 

[u2slow]

My BIL had the same issue after building his shop. His solution was a wifi smart switch. Installed it by the rest of his light switches at the back door of the house; switches lights in/on the shop.

 

[ard]

Exactly. I assume that's the reason for the "only one feeder circuit to detached building" rule.

When I wrote the subject line, I meant to imply that I was worried about meeting code *and* being safe, which are generally well synchronized. Perhaps I should have just left it as "code question" in retrospect.

But then you can NEVER have three way switches between bulidings, correct? Per code?

In your case, you could have one sub panel per building- so not the typical "main panel with disconnect ojn the big strucutre. Instead lets say the maindisconnect is two 200A lugs on a panel, one feeding a 200A sub for the main home the other feeding the second bultding.

Where you feed the switch between these two 'equal' buildings doenst matter... even if you powered the switch off the distant building, and run it 'back' to the main building, you could turn off the subpanel for the main building and still have the distant energized- and feeding that one light on the main.

Sorry to turn this into "CodeTalk"

Anyone?

 

[larry4406]

First to be clear, I am not a sparky...

I too am wanting to do the right thing per Code, but I do want the lighting on my outbuilding(s) to be switched from my house from which they are supplied power. Discussion on this topic where I tried to obtain help is sporadic but in these two threads:
https://www.garagejournal.com/forum/showthread.php?t=426420
https://www.garagejournal.com/forum/showthread.php?t=426614

I found this somewhat older thread on the same topic from another forum. In it one of the posters cites NEC 225.30 (D) Different Characteristics. Additional feeders or branch circuits shall be permitted for different voltages, frequencies, or phases or for different uses, such as control of outside lighting from multiple locations.
https://forums.jlconline.com/forums...o-buildings-lights-on-one-switch-on-the-other

I found the same thing on this Mike Holt posting https://www.ecmweb.com/code-basics/nec-rules-outside-branch-circuits-and-feeders
If more than one building or other structure is on the same property, each building/structure must be served by no more than one feeder or single or multiwire branch circuit [225.30]. However, there are five exceptions to this. You can have additional supplies for: 4. Different characteristics. Different voltages, frequencies, or uses, such as control of outside lighting from multiple locations [225.30(D)].

These two above non-GJ linked posts indicate that the snap switches on the 3-way and 4-way lighting circuits to the outbuildings are acceptable disconnects. However I found this posting which seems to indicate that snap switches are no longer acceptable for this when the 2014 NEC was issued (2011 version it was apparently ok). If snap switches no longer are approved for this, what does one use?
https://www.electricallicenserenewa...cation-Courses/NEC-Content.php?sectionID=36.0

So I am still confused.

The first non-GJ linked thread does have a low voltage 3-way switch schematic with relays which was one posters method of addressing this question.
https://forums.jlconline.com/forums/filedata/fetch?id=990880

 

[ard]

First to be clear, I am not a sparky...

I too am wanting to do the right thing per Code, but I do want the lighting on my outbuilding(s) to be switched from my house from which they are supplied power. Discussion on this topic where I tried to obtain help is sporadic but in these two threads:
https://www.garagejournal.com/forum/showthread.php?t=426420
https://www.garagejournal.com/forum/showthread.php?t=426614

I found this somewhat older thread on the same topic from another forum. In it one of the posters cites NEC 225.30 (D) Different Characteristics. Additional feeders or branch circuits shall be permitted for different voltages, frequencies, or phases or for different uses, such as control of outside lighting from multiple locations.
https://forums.jlconline.com/forums...o-buildings-lights-on-one-switch-on-the-other

I found the same thing on this Mike Holt posting https://www.ecmweb.com/code-basics/nec-rules-outside-branch-circuits-and-feeders
If more than one building or other structure is on the same property, each building/structure must be served by no more than one feeder or single or multiwire branch circuit [225.30]. However, there are five exceptions to this. You can have additional supplies for: 4. Different characteristics. Different voltages, frequencies, or uses, such as control of outside lighting from multiple locations [225.30(D)].

These two above non-GJ linked posts indicate that the snap switches on the 3-way and 4-way lighting circuits to the outbuildings are acceptable disconnects. However I found this posting which seems to indicate that snap switches are no longer acceptable for this when the 2014 NEC was issued (2011 version it was apparently ok). If snap switches no longer are approved for this, what does one use?
https://www.electricallicenserenewa...cation-Courses/NEC-Content.php?sectionID=36.0

So I am still confused.

The concept that a switch is a disconnect, and is required for a light leg under the exception @ 225.30, seems to be an interpretation that was created by the authors in your citations.

Even if a switch can no longer be considered a 'disconnect' for that leg, an exemption for a disconnect still exists under 225.31/32...

As long as you have a note on the switch that says "Barn Light Switch" you may be OK:

A disconnecting means is required for all conductors that enter a building or structure [225.31]. Install it at a readily accessible location (either outside or inside) nearest the point of entrance of the conductors [225.32]. There are four exceptions to this rule:

1) If documented safe switching procedures are established, maintained, and monitored by qualified persons, the disconnecting means can be located elsewhere on the premises [225.32 Ex 1].

my read.....

 

[johnnyradiant]

So if you had some outdoor lighting that had no wires inside an out building could the building be considered a 'pole' to hang one of the outdoor lights on?

 

[larry4406]

Ard - so as long as the switch is clearly labeled where it’s fed from its good is my takeaway.