200 Amp SE Rated ATS with 150 amp service

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beachshadow

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Cobb County
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Electrical Contractor

This installation failed inspection. Inspector said the ATS panel had to become the service main and have breaker changed to 150A. So, what is the specific NEC Code that does not allow my installation?​

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Looks like you removed the neutral strap in the SE transferswitch, so the inspector is wrong. The breaker in the transferswitch could be a 400 amp, and it wouldn’t matter, the service is still protected by the 150 amp in the meter combo.
 
Why does the sticker say Emergency Disconnect? Are you under the 2020 NEC? Looks like you have a 150 amp service disconnect.
 
Even if the inspector is wanting the new ATS to be the emergency disconnect, it will still not meet the 2020 code unless a disconnect is added to the generator feed. If that’s what he is wanting (it to become the new emergency disconnect) you still will have to add a disconnect to the generator output. (Grouped with the service disconnect, and labeled service disconnect #2 of 2.)
 
infinity said:
Why does the sticker say Emergency Disconnect? Are you under the 2020 NEC? Looks like you have a 150 amp service disconnect.
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SquareD has been putting that on all of there Combination Service Entrance Devices for a while.
 
The meter/main is still the service disconnect, but a sticker needs to be added to direct firefighters to the generator's emergency shutoff.
 
Someone pointed out in another recent thread that there is no 150A MCB available for this frame breaker.

Regardless, the service is still protected by the 150A MCB in the meter combo, and if you’re using an air cooled generator, the largest OCPD would then be 100A.


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electrofelon said:
Looks to me like the service conductors hit the ats first, thus a 230.90 violation if the SE conductors are 150A (#1 CU or 2/0 AL)
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It's actually a meter/main so the service disconnect is the 150 circuit breaker because it's connect directly to the meter by the factory conductors that aren't visible.
 
beachshadow said:

This installation failed inspection. Inspector said the ATS panel had to become the service main and have breaker changed to 150A. So, what is the specific NEC Code that does not allow my installation?​

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If ATS was installed in front of the existing main (service side) then yes it must become the main, and be service rated. But the photos looks like a meter/main, thus the ATS should be a non service rated ATS (yes, generac makes this animal) and installed in what appears to be the proper wireing configuration.
The only failure that might be present is the type of ATS installed, (technically might be a listing violation) cannot visually tell from photos what it is diffinatively, but it does look like the service rated ATS. The "violation" is not the rating, if the feeders are sized to the overcurrent protection provided by the meter/main. IMO.
 
If there is a 150 amp service disconnect with a 200 amp ATS and 150 amp protected conductors what is the violation?
 
infinity said:
If there is a 150 amp service disconnect with a 200 amp ATS and 150 amp protected conductors what is the violation?
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I agree if conductors are sized to the overcurrent protection provided by the meter/main no problem with that even if the ATS rated to a higher amperage.
My only question would be the use of a service rated ATS in a location permitting a non service rated ATS. Generac has within their "listing" that the bonding "not to be removed" on the service rated ATS, thus making it a "technical violation" IF this one is a service rated ATS.
Not sure what safety concern there is in the use of service rated one vs the other might be if all conductors are protected at an appropriately rated device though. We do it all the time with main breaker service rated panels used as a non service sub panel by just removing the bonding.
 
Fred B said:
I agree if conductors are sized to the overcurrent protection provided by the meter/main no problem with that even if the ATS rated to a higher amperage.
My only question would be the use of a service rated ATS in a location permitting a non service rated ATS. Generac has within their "listing" that the bonding "not to be removed" on the service rated ATS, thus making it a "technical violation" IF this one is a service rated ATS.
Not sure what safety concern there is in the use of service rated one vs the other might be if all conductors are protected at an appropriately rated device though. We do it all the time with main breaker service rated panels used as a non service sub panel by just removing the bonding.
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Generac has within there listing instructions for connecting the ATS directly to the Utility. So, consider the context of the statement within their "listing" that quoted. Because it was stated within the context of instructions for connecting directly to the Utility. Please notice within the same set instructions for connecting the ATS directly to the utility. That it also says, "Neutral to Ground jumper wire is provided use if required by code."
The Code would require that we not install the "Neutral to Ground jumper wire". We want to install the ATS to be four wire as will everything load side the service disconnect should be installed. (even dryer outlets and stove outlets).
So, I agree with previous Forum comments:

  1. infinity said: "If there is a 150 amp service disconnect with a 200 amp ATS and 150 amp protected conductors what is the violation?"
  2. infinity said: "It's actually a meter/main so the service disconnect is the 150 circuit breaker because it's connect directly to the meter by the factory conductors that aren't visible."
Thanks to all for the good debate on the subject that I presented. I plan to appeal this with the inspector first rather than go over his head to the chief inspector. I think that might be unethical. I just want a reasonable explanation.
 
Conclusion. I talked to the inspector. The installation was done correctly. He clarified his intentions. The correction is to put a locking means on the meter combo. This would prevent someone from changing the 150A main disconnect to a higher breaker size.
 
beachshadow said:
Conclusion. I talked to the inspector. The installation was done correctly. He clarified his intentions. The correction is to put a locking means on the meter combo. This would prevent someone from changing the 150A main disconnect to a higher breaker size.
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An inspector actually said that? What could he possibly base that request on?
 
beachshadow said:
Conclusion. I talked to the inspector. The installation was done correctly. He clarified his intentions. The correction is to put a locking means on the meter combo. This would prevent someone from changing the 150A main disconnect to a higher breaker size.
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I’ve had them wanting “max fuse” on disconnects, but never on a breaker. He probably figured out he was wrong, and to save face, required the lock.
 
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