2 Generators (not paralleled) , One Building

[Sparky2791]

Had a building owner who currently owns 2 smaller size gen sets ask me today if he could use 2 separate generators to feed loads in his building.
Assuming one will handle life safety loads and the other will handle optional stand-by loads. I am going to dig through the code tonight to see but my initial though is this would not be a problem.

Thoughts......?

 

[d0nut]

Not a problem assuming each generator system has its own transfer switch or switches and you aren't trying to feed the same loads from both systems. Make sure to keep your separately/non-separately derived systems straight. Your emergency generator will obviously have more stringent installation, testing, fuel storage, and maintenance requirements than your optional standby generator.

 

[ModbusMan]

Sure, data centers do this all the time (both parallel and not). As d0nut says, just be sure to keep your grounds and your derivations straight, and be sure to label things appropriately (especially if you have arc flash labels on stuff... you'll need one label for commercial power, and a second for generator).

 

[Sparky2791]

Sure, data centers do this all the time (both parallel and not). As d0nut says, just be sure to keep your grounds and your derivations straight, and be sure to label things appropriately (especially if you have arc flash labels on stuff... you'll need one label for commercial power, and a second for generator).

Good point on the arc flash labels. ATS's are both solid neutral (unswitched) so nothing to worry about with that.
Thanks for the reply.

 

[Sparky2791]

Not a problem assuming each generator system has its own transfer switch or switches and you aren't trying to feed the same loads from both systems. Make sure to keep your separately/non-separately derived systems straight. Your emergency generator will obviously have more stringent installation, testing, fuel storage, and maintenance requirements than your optional standby generator.

Hmmm... your reply made me realize something, the gen set is natural gas, NEC requires dual fuel or approval from AHJ to use natural gas for emergency loads. Thanks for the reply.