Generator inlet vs Ats on 400 amp service

[blueheels2]

So I posted a while back about adding an inlet to a 400 amp service and splitting the generator feed between the 2 panels. Seems this is a violation because of the joined neutrals between the 2 panels.

However I’ve noticed in my research that the standard for hooking up say a 24kw generator to a 400 amp service is the same . Split the generator feed between the 2 panels and you are good to go. I see no mention of a 3 pole ATS making it a separately derived system. So what am I missing. Seems the installs are the same?

 

[hillbilly1]

Technically it should be a three pole switch, but is very seldom done because the neutral current is usually very low on residential single phase services.

 

[blueheels2]

Technically it should be a three pole switch, but is very seldom done because the neutral current is usually very low on residential single phase services.

Yeah got me thinking . I had an inspector in VA tell me a couple of weeks ago that he would pass that 400 amp setup but not the interlock setup. I didn’t think about it at the time but later on I was chewing on it as I’m apt to do and thought there is no difference in the install.

 

[Birken Vogt]

If the neutral that runs between the two transfer mechanisms, subpanels, whatever, is large enough to carry the full neutral current of the system, in case one of the regular neutrals gets somehow disconnected, it should be a non issue.