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Circuits Serving Emergency Lighting

G

Glennman CBO

Silver Member
Joined
Oct 20, 2009
Messages
441
Project: 4000 sq ft A-3 (church), occupant load =211, V-B construction, 2008 NEC.

Where egress lighting is provided per 2006 IBC section 1006.1, and the method of emergency back up is provided by means of battery back up, are the combo exit lights and/or egress lights (that have the battery installed in them) required to be connected to a dedicated circuit?

Thanks all.
 
Re: Circuits Serving Emergency Lighting

Actually the unit equipment must be connected to the same circuit that supplies the normal lighting in the area.

Here is what 700.12 of the NEC says about unit equipment used for emergency lighting.

(F) Unit Equipment. Individual unit equipment for emergency illumination shall consist of the following: (1) A rechargeable battery

(2) A battery charging means

(3) Provisions for one or more lamps mounted on the equipment, or shall be permitted to have terminals for remote lamps, or both

(4) A relaying device arranged to energize the lamps automatically upon failure of the supply to the unit equipment

The batteries shall be of suitable rating and capacity to supply and maintain at not less than 87½ percent of the nominal battery voltage for the total lamp load associated with the unit for a period of at least 1½ hours, or the unit equipment shall supply and maintain not less than 60 percent of the initial emergency illumination for a period of at least 1½ hours. Storage batteries, whether of the acid or alkali type, shall be designed and constructed to meet the requirements of emergency service.

Unit equipment shall be permanently fixed in place (i.e., not portable) and shall have all wiring to each unit installed in accordance with the requirements of any of the wiring methods in Chapter 3. Flexible cord-and-plug connection shall be permitted, provided that the cord does not exceed 900 mm (3 ft) in length. The branch circuit feeding the unit equipment shall be the same branch circuit as that serving the normal lighting in the area and connected ahead of any local switches. The branch circuit that feeds unit equipment shall be clearly identified at the distribution panel. Emergency luminaires that obtain power from a unit equipment and are not part of the unit equipment shall be wired to the unit equipment as required by 700.9 and by one of the wiring methods of Chapter 3.

Exception: In a separate and uninterrupted area supplied by a minimum of three normal lighting circuits, a separate branch circuit for unit equipment shall be permitted if it originates from the same panelboard as that of the normal lighting circuits and is provided with a lock-on feature.
Click to expand...
Chris
 
Re: Circuits Serving Emergency Lighting

Raider posted the code reference, so I will just add that it only makes sense to have the emergency egress lighting on the same circuit . The reason is that if you only have a partial, ie breaker tripped, vs a total loss of power, you want the back up lights to kick in. A dedicated circuit would only recognize a power outage on its own circuit.
 
Re: Circuits Serving Emergency Lighting

Also you don't want them to be able to turn them off, for whatever reason (if they are a nuisance etc) without causing themselves a hardship (missing some desired lighting), or have the dedicated circuit trip and them not realizing it for weeks or months.
 
Re: Circuits Serving Emergency Lighting

"""that it only makes sense to have the emergency egress lighting on the same circuit . The reason is that if you only have a partial,""""

so when an emergency generator is used to power all emergency lights, and no battery bak up,

does the above statement still apply????? if you lose a circuit in one room should the generator come on???????????? and no total loss of power to the building??
 
Re: Circuits Serving Emergency Lighting

cda said:
"""that it only makes sense to have the emergency egress lighting on the same circuit . The reason is that if you only have a partial,""""so when an emergency generator is used to power all emergency lights, and no battery bak up,

does the above statement still apply????? if you lose a circuit in one room should the generator come on???????????? and no total loss of power to the building??
Click to expand...
No, 700.12(F) only applies to unit equipment.

700.12(B) regulates generators and only requires a generator to start upon failure of the normal service.

Chris
 
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