NFPA-496 7.4.10

Discussion created by chenting.elec on Dec 15, 2016

How to interpret the power source requirement in NFPA-496 7.4.10 "The electrical power for the positive pressure air system shall be taken off the main power line ahead of any service disconnects to the control room or shall be supplied from a separate power source."  Can ATS fed by two MCCs inside of the building, which are fed by two different upstream sources be considered?