Genset ATS used as Main Disconnect

[JonC]

Hi everyone,
I came across a 800Amp 120/240V Delta Switchboard that has a service rated 600Amp ATS being used as the Main disconnect, unfused, I have never ran into this before. There is a disconnect for the distribution section after the transfer switch.
In a emergency situuation, you would have to open the ATS, clip the cable tie holding the handle, screw it into the manual bypass, switch the control to manual and shut it off, keeping in mind this part of the panel would be only protected by the 100amp fuse located on the pole fed by the 12kv... Seems like a lifesafty issue to me, but maybe I am just overreacting? The Swithcboard was installed in 2020.
as a side story:
Which makes this a more complicated problem, the customer is wanting to add a battery backup to their solar, so it would intail tapping into the ATS with another ATS to bypass the 250KVA Genset, running 350mcm 200' to the PV and battery pack and back to the ATS. Of course this would be on the utility side, so a fused disconnet would have to be installed... Also the changeover will be a logistical nightmare, having to get the modifications of the Switchboard approaved, while keeping the lights on...
Thanks,
Jon

 

[coop3339]

I don't see an issue as long as the ATS is service entrance rated. Not sure I would set it up like that but I have seen residential generator installations done just this way.

 

[augie47]

I don't think you will find the ATS is Service Rated as it has no inherent OCP.

 

[JonC]

Thanks for the replies, that was my concern; no protection for the 800 Amp Switchboard, ahead of the distribution disconnect. The other concern, the cabinet is accessible, and is on the utility side of the service, just seems like a dangerous set up, you would have the fuses opened on the pole to service the ETS.

 

[Birken Vogt]

Good question, I don't know the answer, but I will point out that the big, common GE 200 amp MTS with the round steel rod loop handle is (was?) marked "suitable for use as service equipment" even though no fuses in it. What are the rules on that?

 

[LarryFine]

Good question, I don't know the answer, but I will point out that the big, common GE 200 amp MTS with the round steel rod loop handle is (was?) marked "suitable for use as service equipment" even though no fuses in it. What are the rules on that?

The OCPD may be adjacent to the service switch.

 

[qcroanoke]

Good question, I don't know the answer, but I will point out that the big, common GE 200 amp MTS with the round steel rod loop handle is (was?) marked "suitable for use as service equipment" even though no fuses in it. What are the rules on that?

Most service switches are good for service equipment if they have a neutral bar and are installed adjacent to a fused or a disconnect with a breaker in it.

 

[JonC]

Makes sense that you would have a Main breaker or Fused Disconnect ahead of the ATS.
An interest twist, looking at the manual on the 600A Zenith ATS it says that it cannot be manually switched under load, so it cannot be used as a Main Disconnect...