Main service disconnect switch before / after ATS?

[anbm]

Will the building's main service disconnect be installed between utility transformer and ATS or can be downstream of ATS...?
The building is powered from utility transformer but has a standby generator as backup power source.

 

[augie47]

If the ATS is not service rated it must be installed after the service disconnect.
(If it is service rated it would have a service disconnect as an integral part)

Added: Your Code reference is 230.82 where ATS are not listed as items that can be installed ahead of service equipment therefore the ATS would have to be rated as service equipment.

 

[LarryFine]

Whichever the service conductors hit first is, or becomes the service disconnect, and everything beyond that point, including the second, now-redundant disconnect must be wired as a sub-panel, with separated neutral and EGC.

 

[anbm]

Please see image attached, will this be code compliance as the ATS does not have main breaker, ATS is grounded as service entrance.
Both ATS and MSA are in same room. Thank you!

 

[augie47]

IMO. Not Code compliant as a non-service rated transfer switch is not one items allowed ahead of the service disconnect.

 

[anbm]

IMO. Not Code compliant as a non-service rated transfer switch is not one items allowed ahead of the service disconnect.

The ATS is service rated ATS with neutral bond to ground bus but does not have a main CB. So my question is whether the ATS needs a main CB, if it is, then panel MSA doesn't need a main CB.

 

[augie47]

Not sure what to tell you as I've never seen a Service Rated ATS with no main breaker or fusible switch. I'd check the listing for any stipulations.

 

[Nuber]

Please see image attached, will this be code compliance as the ATS does not have main breaker, ATS is grounded as service entrance.
Both ATS and MSA are in same room. Thank you!

I believe that 230.82(5) allows circuits for standby power systems to be installed ahead of the service disconnect. Your referenced drawing seems legit.

 

[NTesla76]

I believe that 230.82(5) allows circuits for standby power systems to be installed ahead of the service disconnect. Your referenced drawing seems legit.

I thought you still needed a separate disconnecting means. I'll have to look it up.

 

[augie47]

I believe that 230.82(5) allows circuits for standby power systems to be installed ahead of the service disconnect. Your referenced drawing seems legit.

The I read that rerference is "taps to supply ,,, circuits for standby power...." not for ATS systems... (I could be wrong)

 

[anbm]

The I read that rerference is "taps to supply ,,, circuits for standby power...." not for ATS systems... (I could be wrong)

I agreed with Augie47, that is a tap to the main service feeder to feed main panel, this won't relate to my sketch which has ATS is also the main.