Emergency Lighting

[ksavoie]

I'm designing the electricl lighing and exit signs for a stairway in an office building. I have spec'ed out exit lights and stair lights with battery backup in each fixture. My question is because I have battery backup in each device, do these fixtures have to be feed on their own circuit? or can I just tap of an existing circuit?

 

[ykee]

Emergency lighting should be fed, is possible from the same circuit as lights in the vicinity -- if the breaker trips, or something else happens and the lights go out, you still have some.

That said, check your code!

 

[rbulsara]

NEC requires emergency light fixtures to be connected to the local lighting circuits, tapped ahead of the light switch.

If dedicated circuits are used, they and normal light circuits need to arranged such that loss of any one circuit shall not cause loss of all normal lights in the area.

 

[rbulsara]

Look up NEC 700 and NFPA 101.

 

[ksavoie]

Correct me if I'm wrong. 700.15 states "No appliance and no lamps, other than those specified as required for emergency use, shall be supplied by emergency lighting circuits.

In my case the battery is the "emergency circuit" so the "normal supply circuit" can feed the emergency lights along with the hall way lights leading up to the stairway.

 

[rbulsara]

Your emergency circuit is actually the battery source in the battery pack you mentioned. The tap from the normal light is only to the charge the batteries and is not the emergency circuit. Normal power does not light the "emergency light" when normal power goes out!!

 

[DrDrreeeaaa]

Australian standards require a test facility where you can de energise all the emerg. luminaires to test their battery packs. This is very commonly done by having all the luminaires on the one circuit.