Multiple generators and multiple transfer switches diagram

[mbish]

I am installing multiple generators (240V/50A) and multiple transfer switches (Reliance A506A) to feed one 200A panel for a client. I consulted with Reliance tech support and want to run this by you guys:


After looking at my drawing, where it says 'Fridge' as example load, just pretend it says 'Lights' -- mmm'kay?

 

[iceworm]

I can't tell what you are asking about. I did look at the installation manual and I can say, the installation will not look like your picture.

Each of the transfer switches is made up of 6 each, 1pole, double throw, center off switches. The manual has a pretty good picture on how to wire 1 pole and 2 pole loads

The attached sketch shows how I suspect the transfer switch internals are wired.

You didn't ask, however, if your client truly needs 25KVA of temporary power, there are perhaps cleaner ways of doing this - although maybe not cheaper.

the worm

 

[mbish]

I can't tell what you are asking about. I did look at the installation manual and I can say, the installation will not look like your picture.

Each of the transfer switches is made up of 6 each, 1pole, double throw, center off switches. The manual has a pretty good picture on how to wire 1 pole and 2 pole loads

The attached sketch shows how I suspect the transfer switch internals are wired.

You didn't ask, however, if your client truly needs 25KVA of temporary power, there are perhaps cleaner ways of doing this - although maybe not cheaper.

the worm

Good point. I was concerned about both generators tied to the same neutral bar in the panel. I can handle the single pole/double pole wiring. The manual is quite explicit on how to do that and yes, your sketch shows the internals of the transfer switch which I glossed over in mine. Again, I was too terse in my original post and I poorly articulated my concerns with the combined GND/NEUTRAL bus bar connections. Also, with my wiring there should be no way that the generators can feed the same hot line.

The client doesn't want to get a full house generator because of the fuel supply issue (no natural gas and limited supply of LP), plus he already has one generator for other work (and he knows he has to float the neutral if he plugs into this - I am adding marquee signs next to the generator connection to CMA).

 

[iceworm]

Good point. I was concerned about both generators tied to the same neutral bar in the panel. ...
... my concerns with the combined GND/NEUTRAL bus bar connections. ....

You don't show, however, I suspect the N-G bond is in the panel, and you show the gens have the N-G bond removed. These transfer switches are designed such that one can have the utility powering the panel, and individual loads powered from the generators. All three sources can be on at the same time. Doesn't sound like a great idea, but I don't see anything inherently dangerous - other than:

... (and he knows he has to float the neutral if he plugs into this ....

My guess that will never happen. Against the code, but not too dangerous.

... The client doesn't want to get a full house generator because of the fuel supply issue (no natural gas and limited supply of LP), plus he already has one generator ...

The fuel supply shouldn't matter. Same fuel for one bigger gen as opposed to two smaller ones. The issue I see is with two switch panels, loads split between the two, and only one gen (which will happen), she won't be able to turn on the ones that are needed. Maybe set up the switch panels with one as the "Critical Loads" and the other as the "Nice to Have".

None of which you asked.

As for what I think you are asking:
Not inherently dangerous. I don't see any code issue.
(well except an inspector bursting into flames as he walks by)

the worm