service rated transfer switch

[wyboy]

I have a 400 amp service rated transfer switch with service disconnect and main bonding jumper in the enclosure with the transfer switch. The transfer switch does not switch the grounded conductor so it is not a separately derived system. The feeder from the generator (a 400 amp breaker is internal to the generator) will have a grounded conductor as well as an equipment ground. The transfer switch’s neutral and ground are tied together by the main bonding jumper so the grounded conductor as well as an equipment ground from the generator will be tied together at the transfer switch. Is this install compliant? :?

 

[augie47]

Sounds right.
The T/S is the service disconnect so neutrals and equipment grounds would be terminated on common buss.
Just make sure your neutral is not bonded at the generator.

 

[ActionDave]

I agreek with augie, he is wise.

 

[jap]

Sounds right.
The T/S is the service disconnect so neutrals and equipment grounds would be terminated on common buss.
Just make sure your neutral is not bonded at the generator.

Since there is a 400 amp main breaker in the Generator, is that not the 1st means of disconnect, meaning, the Neutral and EGC from the generator need to be kept seperate in the XFR Switch?


JAP>

 

[augie47]

Since there is a 400 amp main breaker in the Generator, is that not the 1st means of disconnect, meaning, the Neutral and EGC from the generator need to be kept seperate in the XFR Switch?


JAP>

Since the XFR switch is service, you have to have a main bonding jumper so Neutral & Equip grounds are going to be "common" there. I understand you question and can see the need for separation if the generator was a SDS but in this case it seems the equip ground is the only method for grounding/bonding the generator itself.

 

[jap]

Since the XFR switch is service, you have to have a main bonding jumper so Neutral & Equip grounds are going to be "common" there. I understand you question and can see the need for separation if the generator was a SDS but in this case it seems the equip ground is the only method for grounding/bonding the generator itself.

Understood, but seeing as the EGC back to the generator would actually create a parallel return path when it seems a "Non Service Entrance Rated" Transfer switch should be used in this scenario should it not?

JAP>

 

[ActionDave]

Understood, but seeing as the EGC back to the generator would actually create a parallel return path when it seems a "Non Service Entrance Rated" Transfer switch should be used in this scenario should it not?

JAP>

No parallel paths if the neutral bond is lifted at the generator it is a non sds and needs a separate equipment ground.

 

[jap]

I see wher that was mentioned and that makes sense.
Sometimes it just takes me longer.


JAP>