Generator (again)

[One-eyed Jack]

As it stands now, I don't see any way to justify not having the equipment grounds.
It also seems like if we removed all other obstacles, without the EGC, the requirement to bond the neutral is going to cause GF problems.

In essence you are back to the age old situation of haveing a second and/or 50th grd to a service neutral. If you have one POCO trans. supplying 20 homes you have the potential for 40 grd rods connected to the service neutral. Now connect your genset with or without the 5th wire. The same 40+ grd rods are still connected to your service neutral via the hardwired connection of the neutral to the ges . If you take special care to" isolate" the Poco neutral and the premise neutral and switch it in the ATS you will probably have your SDS. We have been living with the so called parallel grd path since before I was born. It may be deemed a hazard but that is the way it is. I have seen a situation where one of these prohibited parallel grd/neutral paths was open on the Poco side three spans from the residence. Everything metal in the house was hot until this grd was restored. Hazard or not this fixed the problem.

 

[augie47]

cf, They should have hired you to begin with. I am much impressed !
There was a meeting of half-dozen inspectors and one CMP member to review it this morning.
The verdict was if the "walled area" surrounding the generator is classified as a building (locally that is a Building Official call not a NEC definition call)
then it must be 5 wire because of 250.32 ground path.
If the generator is considered "free standing" (not a building but a generator with "privacy fencing", the the 4 wire is allowable and the generator neutral will be bonded/grounded on the "load" side of the ATS as you have shown.
The only change in your revised sketch was the addition of a bond from neutral to generator frame

Again, my sincere appreciation and admiration.