Transfer Switch

[jap]

When would a Manual transfer Switch not be required to have a Center Off Position?

 

[charlie b]

I should think that it is never required.

 

[iwire]

If it is a service rated transfer-switch it is required to be able to disconnect both sources. Beyond that I agree with Charlie.

 

[jap]

does it have to have Overload Protection and a Neutral to be service Rated?

 

[Pierre C Belarge]

For the transfer switch itself to be listed as a service disconnecting means, it will be required to have a disconnecting means and overcurrent protection.
see 230.82

 

[tom baker]

For the transfer switch itself to be listed as a service disconnecting means, it will be required to have a disconnecting means and overcurrent protection.
see 230.82

There are service entrance rated TS's that have no overcurrent protection...Sq D makes them, we have one in a maint facility.

 

[Mvillines]

Transfer switches rated as service equipment are not required to have over-current protection within the TS switch but you would have to comply with 230.91 that requires the switch and OC protection to be immediately adjacent to one another.

 

[Pierre C Belarge]

When would a Manual transfer Switch not be required to have a Center Off Position?

does it have to have Overload Protection and a Neutral to be service Rated?

Two parts of a question.

For the transfer switch itself to be listed as a service disconnecting means, it will be required to have a disconnecting means and overcurrent protection.
see 230.82

My answer to his question was specific to the question asked.

I said for the transfer switch ITSELF to be listed, it would need the sum of the parts.

 

[Pierre C Belarge]

To add to my above statement, I am aware the overcurrent protection can be ADJACENT TO the transfer switch, not necessarily part of the actual switch. I posted so in another thread.

 

[jap]

What classifies a piece of equipment as being service entrance rated?
Is it the Disconnecting Means, Overcurrent protection,Neutral connection or a combination of all 3? I'm unclear of exactly what the definition of Service Entrance Rated is.

 

[augie47]

What classifies a piece of equipment as being service entrance rated?
Is it the Disconnecting Means, Overcurrent protection,Neutral connection or a combination of all 3? I'm unclear of exactly what the definition of Service Entrance Rated is.

Pretty much the "combination" you mentioned.
NRTLs such as UL will "list" the equip met as being service rated.
Equip met as small as a 30 amp fusible disconnect and as large as 1000s of amp switchboards can all be "service disconnects"
Some doublethrow swathes are listed as "suitable as service equipment".
You might also refer to Art 100 "service equipment"

 

[jap]

So the "Service Entrance Rated" Sticker is actually the only way we know if a piece of equipment is service rated or not.

 

[Pierre C Belarge]

Here is a pretty good graphic of how transfer switches can be installed as part of the service.

Graphic

Once on this page, scroll down to
Service Entrance - Rated Transfer Switch - Cliffordpower.com

 

[LarryFine]

Here, Pierre: Click herehttp://www.cliffordpower.com/pdf/CPS_info_sheet-34_Service

 

[augie47]

So the "Service Entrance Rated" Sticker is actually the only way we know if a piece of equipment is service rated or not.

Pretty much.
Your DT switch may be listed as service equipment. It may or may not be fusible, but note 230.91 requires overcurrent protection to be an integral part or immediately adjacent to your service disconnecting means.
In addition, 230.to requires a disconnecting means for all conductors from the service conductors so an "off" position is practical.