Hello,

I have an existing emergency power dist. system with life safety & non-life safety loads. There is a requirement to add new life safety branch circuits. The existing emer. pwr system currently does not have overcurrent devices selectively coordinated.

Once we modify the existing system, is a coordination study required per NEC 700.27? The system was designed and constructed prior to 2005 NEC.

Thanks in advance.

dbravo:

I would discuss your situation with the AHJ in the town the project is in.

The extent of the mods you have to perform may be the deciding factor.