Transfer switch in residence outside or inside ?

[ritelec]

I’m thinking a transfer switch can be mounted outside or inside a dwelling right next to a main panel BUT something is telling me that if it’s mounted inside, when it’s in utility power mode that there will be too much un protected conductor running in the house through the transfer switch to the panel. ( sorry for the run on sentence )
Can the transfer switch be mounted inside with this extra conductor length or is it best to mount it outside ( note. 2017 no emergency exterior switch )
thank you.

 

[infinity]

Inside or outside is code compliant. Are you using a service rated transfer switch?

 

[ritelec]

I would think. I’m actually talking to a friend who’s building a house in NY state.
We are talking about a generator and I was questioning the length of unprotected wiring in the building thinking the switch would be better placed outside.
So on a regular service they want line unprotected conductors to be a short distance to main panel but if a transfer switch is installed inside the conductors can be longer while still unprotected?

 

[LarryFine]

If you treat the service-rated ATS as the main disconnect, running directly to it from the meter, then your unprotected conductors won't be any longer than they would be without an ATS.

The conductors from the ATS to the breaker panel will be a feeder, and protected by the ATS. Your panel won't even need to include a main breaker. Wire it as you would any sub-panel.

 

[ritelec]

The ATS has over current protection in it?
I thought it just switching ?

I can understand if it had oc protection but without it wouldn’t from the meter through the transfer to the panel be not protected ??

 

[infinity]

The ATS has over current protection in it?
I thought it just switching ?

I can understand if it had oc protection but without it wouldn’t from the meter through the transfer to the panel be not protected ??

If you use a service rated ATS it will have an OCPD so you can eliminate a main CB in the panel and use a MLO. All of your GEC's will go to the ATS. As Larry stated if you do install it on the inside then you just bring your SEC's from the meter directly into the ATS just like you would a regular service panel.

 

[ritelec]

Got it. Thank you.

 

[Little Bill]

This would be no different than if your inside panel was a good distance from the meter. You would have to have a disconnect outside because you can't have unfused conductors running in the house. (with limited exceptions, such as the distance)
If the panel is going to be placed where there is a long run from the meter, then the ATS should be service rated and placed outside by the meter. Then a 4-wire feeder should be ran. You could put in a disconnect outside and place the ATS inside, but that would be a waste since the ATS is a disconnect if service rated.

 

[electrofelon]

The ATS has over current protection in it?
I thought it just switching ?

I can understand if it had oc protection but without it wouldn’t from the meter through the transfer to the panel be not protected ??

There are "switch only" transfer switches, but the vast majority of small residential transfer switches have a breaker in them and are service rated.

 

[LarryFine]

The ATS has over current protection in it?
I thought it just switching ?

I can understand if it had oc protection but without it wouldn’t from the meter through the transfer to the panel be not protected ??

That's why questions often spawn more questions. You need to tell us what type of ATS you're asking about.

 

[Fred B]

This would be no different than if your inside panel was a good distance from the meter. You would have to have a disconnect outside because you can't have unfused conductors running in the house. (with limited exceptions, such as the distance)
If the panel is going to be placed where there is a long run from the meter, then the ATS should be service rated and placed outside by the meter. Then a 4-wire feeder should be ran. You could put in a disconnect outside and place the ATS inside, but that would be a waste since the ATS is a disconnect if service rated.

This distance is highly variable from municipality to municipality , and no real distance given in code other than "nearest the point of entrance". 230.70(A)(1)

I see 2 reasons to do it either way inside or outside, exempting consideration of limitations of ATS itself. 1. Distance of generator cable that would need to be run for placement in either location. 2. Would service cable need to be replaced anyway? Yes, Would put outside. No, would put inside. That would limit the length of a 4 conductor cable for a service rated ATS (most GENERAC ATS are such).
Also can save some money with a NEMA 1 vs a NEMA 3 ATS by having indoors.

 

[MTNDEWELEC]

Would the fact you are putting in a new “service main disconnect” mean you must now meet the 2020 standards of the NEC requiring a emergency disconnect? Therefore it would be required to mounted outside and becomes the emergency disconnect for the house. Code reference NEC 230.85. Asking for similar situation

 

[ptonsparky]

Would the fact you are putting in a new “service main disconnect” mean you must now meet the 2020 standards of the NEC requiring a emergency disconnect? Therefore it would be required to mounted outside and becomes the emergency disconnect for the house. Code reference NEC 230.85. Asking for similar situation

I believe you are correct IF you are under the '20 and IF you want to designate it as such. Another disconnect could be used.

 

[MTNDEWELEC]

I believe you are correct IF you are under the '20 and IF you want to designate it as such. Another disconnect could be used.

I am under the impression, that if you establish a new service disconnect, you have to meet the new standards of the NEC. Which would require a emergency disconnect installed correct?