Transfer switch wiring

[GerryB]

Recently I installed a 200 amp manual transfer switch for a customer. I mounted it adjacent to the panel, removed the SEU from the panel and fed the top line side of the transfer switch, re-fed the panel from the center load of the transfer switch. The local utility doesn't like it. They have one paragraph in their guide book about generators. "Such installations require an adequately sized double throw or open transition switch. The switch must be on the load side of the main disconnect switch and metering equipment. The switch must disconnect the Company's lines from the Customer's wiring before the generator can be connected to supply electricity. " The only way to do this with the 200 amp service is to change the meter outside to a combination meter with 200 amp breaker. I thought the transfer switch became the main disconnect and the existing panel becomes a sub-panel, and one local electrical inspector agreed. From the utility's standpoint nothing has changed. The SEU is still hot from the meter outside to the first point of disconnect, (3 or 4 feet). Any replies?

 

[stickboy1375]

Recently I installed a 200 amp manual transfer switch for a customer. I mounted it adjacent to the panel, removed the SEU from the panel and fed the top line side of the transfer switch, re-fed the panel from the center load of the transfer switch. The local utility doesn't like it. They have one paragraph in their guide book about generators. "Such installations require an adequately sized double throw or open transition switch. The switch must be on the load side of the main disconnect switch and metering equipment. The switch must disconnect the Company's lines from the Customer's wiring before the generator can be connected to supply electricity. " The only way to do this with the 200 amp service is to change the meter outside to a combination meter with 200 amp breaker. I thought the transfer switch became the main disconnect and the existing panel becomes a sub-panel, and one local electrical inspector agreed. From the utility's standpoint nothing has changed. The SEU is still hot from the meter outside to the first point of disconnect, (3 or 4 feet). Any replies?

First off, That transfer switch needs to be Rated for use as service disconnect, also, the POCO can override any other rules, you could always install a 200 amp disconnect before the transfer switch, I do this a lot actually... since the manual transfer switches I buy are not rated for use as service disconnecting means....

 

[ActionDave]

Same here. Rarely use the transfer switch as a service disconect.

 

[meternerd]

I doubt very many POCO's would allow it even if it was rated as service equipment. A transfer switch is considered customer equipment and must be downstream of the service disconnect, which is the main breaker as far as we're concerned. At least that's the way our utility sees it.

 

[Strathead]

I doubt very many POCO's would allow it even if it was rated as service equipment. A transfer switch is considered customer equipment and must be downstream of the service disconnect, which is the main breaker as far as we're concerned. At least that's the way our utility sees it.

I have not seen a service rated manual transfer switch, so I have no idea how it would be contructed. That said, why wouldn't most utlity companies allow a service rated transfer switch? They have double set of breakers, which would comply with the section from the POCO that the OP questioned.

 

[stickboy1375]

I have not seen a service rated manual transfer switch, so I have no idea how it would be contructed. That said, why wouldn't most utlity companies allow a service rated transfer switch? They have double set of breakers, which would comply with the section from the POCO that the OP questioned.

The service rated transfer switches I have installed did not contain OCP, I took advantage of 230.91 Location And the way it is constructed is that the neutral lugs have a main bonding jumper...

 

[kwired]

As some have already said - if the transfer switch is rated for use as service equipment you don't have an NEC issue.

POCO could still have their own rules. BUT,

Most POCO don't care what you have once past the meter, I am suprised they said anything here.

 

[stickboy1375]

As some have already said - if the transfer switch is rated for use as service equipment you don't have an NEC issue.

POCO could still have their own rules. BUT,

Most POCO don't care what you have once past the meter, I am suprised they said anything here.

I'm surprised as well, but just goes to show you...

 

[GerryB]

I'm surprised as well, but just goes to show you...

The transfer switch says "suitable for use as service equipment" no OCP anywhere, and that it complies with NEC 702. It is adjacent to the Panel. I am meeting with the building inspector (not an electrician) since POCO reported it no permit. Turns out there are a few just in this small town I was told. I think it started with an automatic TS with no main that they started questioning. They told me in the office that UI is going to start sending a list to towns when anyone calls to have a meter unlocked.

 

[iwire]

A service rated transfer switch is a transfer switch that is suitable for use as the service disconnecting means.

 

[Pierre C Belarge]

Service rated

Service rated

A listed - service rated transfer switch has a disconnecting means that has overcurrent protection. They are quite common and installed more today than ever before.

If a utility representative tells one that it is not an accepted practice, I would request of the the utility person to provide the document number for that. ALL utility companies provide answers in writing (utility book - usually named after a color - such as "Green Book, Blue Book", etc...)

I am responding to this post, due to a unique situation in our area that has me puzzled.

'Supposedly', a national representative of the IAEI, and CMP member has told a number of inspectors that the conductors on the load side of a service rated transfer switch installed as a service disconnect, should be bonded together and not isolate the neutral/egc.
He also 'supposedly' stated that a service rated transfer equipment is not classified as service equipment.

Has anyone else heard the same?

I have a call into his office and hope to hear from him in the next couple of days.

 

[ceb58]

A listed - service rated transfer switch has a disconnecting means that has overcurrent protection. They are quite common and installed more today than ever before.

If a utility representative tells one that it is not an accepted practice, I would request of the the utility person to provide the document number for that. ALL utility companies provide answers in writing (utility book - usually named after a color - such as "Green Book, Blue Book", etc...)

I am responding to this post, due to a unique situation in our area that has me puzzled.

'Supposedly', a national representative of the IAEI, and CMP member has told a number of inspectors that the conductors on the load side of a service rated transfer switch installed as a service disconnect, should be bonded together and not isolate the neutral/egc.
He also 'supposedly' stated that a service rated transfer equipment is not classified as service equipment.

Has anyone else heard the same?

I have a call into his office and hope to hear from him in the next couple of days.

If the conductors came from the meter base why wouldn't the neutral and EGC not be bonded in the SE transfer switch? It would be the "sub-panel" after the ATS where the N-G are now separated and the neutral isolated.

But I agree if it is rated as service equipment then why is not classified as such

After rereading I think i misunderstood about the bonding.
:slaphead: