4-pole ATS, solid neutral outside

[sevis]

Hopefully this is a simple question. I have a 4-pole ATS and wondering if it is possible to bypass the neutral in the ATS and solidly pass the neutral outside of the ATS, effectively turning this into a 3-pole switching system.

The issue is that we have a non-separately derived generator, but the ATS that arrived on site is 4-pole. I'm mainly looking for any code references or anything to indicate whether this is possible or not. After a pass through the NEC and NFPA 110 I was unable to locate anything to indicate that this wouldn't be possible.

 

[sevis]

Hopefully this is a simple question. I have a 4-pole ATS and wondering if it is possible to bypass the neutral in the ATS and solidly pass the neutral outside of the ATS, effectively turning this into a 3-pole switching system.

The issue is that we have a non-separately derived generator, but the ATS that arrived on site is 4-pole. I'm mainly looking for any code references or anything to indicate whether this is possible or not. After a pass through the NEC and NFPA 110 I was unable to locate anything to indicate that this wouldn't be possible.

I may have answered my own question. This doesn't appear like an ATS specific issue which is why I was unable to find anything. There are several places in code that prohibit the routing of the neutral in separate raceways. Routing the neutral around the ATS would violate this. Thanks for people that have read and looked into this but I think we are done here.

 

[ActionDave]

You can run the neutral inside the transfer switch and not switch it.

 

[sevis]

I guess I assumed there would not be room to do that. If possible that would save us a lot of money

 

[LarryFine]

The neutral should be switched if each source has the neutral grounded ahead of the ATS, OR it should not be switched, and grounded once in or after the ATS,

 

[RD35]

Your non-separately derived generator has a floating neutral that is not bonded to ground. So, the neutral connection must be solid and not switched. I'm with ActionDave on this one. Tie all of your neutrals together (two supply and one load) on a listed insulated distribution block inside the transfer switch and you should be good to go. Hopefully there is plenty of room for the block. I'd think a mountable block would be best in order to avoid interfering with the moving parts in the switch. If not, you might be able to install a large nipple and an adjoining J-box to house the distribution block.

 

[infinity]

Transfer switches usually have enough room for a splice.