Using an existing generator

[alixenos]

Hello,

I have an existing 250 KW 120/208 3 phase generator that provides an emergency to a building.
In addition to that an existing 18 KW generator is connect to two panels via two ATS'es

I want to remove the 18 KW existing generator and connect those two panels to the existing 250 KW generator.

I'm new designer, so I'm trying to figure out what articles in the NEC I have to focus on to reconnect and spec the conductors/disconnecting means, over current protection, etc for this task.

Its a broad question, but I tried articles 445, 517, 700, 701, and 702 and its very confusing.

Thank you so much.

 

[don_resqcapt19]

First you have to know if this is an Emergency System covered by Article 700, or a Legally Required Stand-by system covered by Article 701, or an Optional Stand-by system covered by Article 702. Look at the scopes of those articles to help determine which one applies. It may be that more than one Article would apply and will typically require multiple transfer switches. No part of the wiring system for an Article 700 system can be in the same raceway or enclosure with any other wiring system.