Whole Building Generator

[Eng]

I have an existing condition where the life safety (select lighting, fire alarm, nurse call etc) is separeted out by an ATS and fed from the Normal MDP and also the on site generator.

The client wants eliminate the generator that they currently have and install a larger one sized to handle the entire facility. I will be intercepting the incoming utility feeder and connected that to a new ATS. My questions is...how do I handle the existing life safety ATS? Do I need to power this ATS directly from the utility transformer, which would create a separete service. Seems like I cannot just connect the MDP to the new ATS and leave the life safety ATS connected to the MDP and the new generator.

Young engineer looking for some guidance.

 

[MadWulf]

There are a couple options for you.

You can install a central battery UPS specifically for the emergency lighting, in lieu of installing battery packs in each individual light fixture. Make sure there is battery backup for any fire alarm and security panels. With the life safety items covered by batteries, the generator is now considered an optional standby unit. You can have one ATS for the entire facility.

The other option would be to have two or more transfer switches. I am unsure how many breakers are in the MDP. If there are multiple breakers you could set a new MDP with two breakers. Once for the life safety ATS and the other breaker to backfeed the existing MDP through an ATS.

This is a simplistic view, but gives you a couple options.

 

[hillbilly1]

Another possibility is to leave transfer switch as connected, re-route generator feed from old generator to second breaker installed in new generator if old generator is to be removed. New generator will have to be maintained to the same requirements as the old one, same required start and transfer times,etc.