Emergency Power Generators

Q: I am a consultant and I visited an ASC that had a natural gas generator housed indoors, located in the basement of the facility. The ATS switch was located in the same room as the generator. I am not used to seeing generators located inside of the building. Is the ATS allowed to be in the same room? Also, there was no emergency battery backup light at the location of the generator and there was no emergency stop button located anywhere in or outside of the facility. Isn’t this required?

A: The fact that the generator is located inside the building may be acceptable, depending when the generator was installed. NFPA 110-2010, section 7.2.1 says the generator shall be installed in a separate room and emergency power supply system equipment shall be permitted to be installed in this room. So, this allows the generator to be installed inside the building in a room, and this allows the ATS to be mounted in the same room.

According to section 7.2.1.1 the room must be separated from the rest of the building by 2-hour fire rated barriers, or the generator may be located outdoors. So, when you see generators mounted inside in a room, check the entrance door (if the door connects the room to the rest of the building) rating as it must be 90-minute fire rated, and the walls must be 2-hour fire rated without any unsealed penetrations.

According to section 7.2.1.2 nothing else, other than what has been described, may be permitted in this room. So the room cannot be used to store ladders, equipment, supplies, etc.

According to section 7.2.3, the room housing the generator must be designed and located to minimize the damage from flooding, caused by fire-fighter flooding; sewer backup; natural disaster. So, locating a generator in a basement does not seem to fit this requirement. This requirement was also found in the 1999 edition of NFPA 110, which was required to be complied with by CMS since March 11, 2003. So, if this generator was installed since March 11, 2003, I would say it is subject to a finding by a surveyor for not locating the generator in an area that would not be affected by flooding.

According to section 7.3.1, the generator equipment location must be provided with a battery-powered emergency lighting. So, if there is no battery powered emergency lighting unit, then that is a potential finding by a surveyor.

According to section 5.6.5.6 the generator must have a remote manual stop station located outside the room that houses the generator, and the remote manual stop station needs to be labeled. So, again, if there is no remote stop switch, then that is another potential finding by a surveyor.