700.17 Branch Circuits for Emergency Lighting

[m sleem]

I am lost in this section regarding the supply of lighting system, we always segregate between normal circuits and emergency circuits e.g. there are 10 lights located in a corridor on ceiling (not for exit) all are working during normal power, assuming that three out of them are assigned for emergency, generally we feed the emergency circuit (from generator through ATS+panel) assigned for the three lights from the emergency panel & the normal circuit assigned for the rest seven lights from the normal panel, the questions are:

1- Is the 1.5 hrs battery backup (either individual or CBS) still required for emergency lights ?
2- Do we still need to supply the emergency lights by two circuits from two different ATSs/ATS+Normal panel ?
3- If no.2 is "no", what is the case of exit signs/lights ?

 

[ron]

1- Is the 1.5 hrs battery backup (either individual or CBS) still required for emergency lights ?
2- Do we still need to supply the emergency lights by two circuits from two different ATSs/ATS+Normal panel ?
3- If no.2 is "no", what is the case of exit signs/lights ?

1- No, since you are providing the segregated emergency power from a gen. That is enough Article 700 source

2- No, that requirement doesn't exist, but you need multiple lamps per 700.16

3- 700.16 includes egress lights and exit signs

 

[david]

but you need multiple lamps per 700.16

just for clarification no single lamp in an area, that doesn't mean multiple lamps per fixture

 

[m sleem]

2- No, that requirement doesn't exist, but you need multiple lamps per 700.16

Multiple lamps, would that means multiple fixtures?



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[RD35]

1- No, since you are providing the segregated emergency power from a gen. That is enough Article 700 source

If you are trying to eliminate battery ballasts altogether, then your generator back-up must be capable of coming on line within 10 seconds of an outage per 700.12

On the question concerning multiple lamps, I read that to mean the failure of any single lamp, ballast, or single-lamp/ballast fixture. So, if your emergency light has two incandescent lamps it is fine since one lamp failure will not leave the room totally dark. If your emergency fluorescent fixture has only one battery ballast and it is the only fixture in the room, then you need another source of battery back-up (or generator backed) light so as to not leave the room in "total darkness" if any single lamp/ballast fails (700.16 paragraph 3 - nec2017)

 

[m sleem]

If you are trying to eliminate battery ballasts altogether, then your generator back-up must be capable of coming on line within 10 seconds of an outage per 700.12

On the question concerning multiple lamps, I read that to mean the failure of any single lamp, ballast, or single-lamp/ballast fixture. So, if your emergency light has two incandescent lamps it is fine since one lamp failure will not leave the room totally dark. If your emergency fluorescent fixture has only one battery ballast and it is the only fixture in the room, then you need another source of battery back-up (or generator backed) light so as to not leave the room in "total darkness" if any single lamp/ballast fails (700.16 paragraph 3 - nec2017)

So, one lamp in down-light in one room like a janitor is not permitted.

 

[m sleem]

I'll try to sort it down as follows:

- In the case of a large area, more than one emergency light can be installed.
- In the case of a small area that does not require more than one emergency light, it is necessary to install two (at least) lamps (LED, Fluorescent, HID) with two (at least) Ballast / Driver in the absence of a battery while the generator is there .
- In the case of a battery with a generator, two (at least) lamps (LED, Fluorescent, HID) with (1) Ballast / Driver can be installed.

The conclusion is relying on two units of each component of the emergency light.

Am i correct in the above conclusion !

 

[LarryFine]

So, one lamp in down-light in one room like a janitor is not permitted.

I wouldn't think a janitor's closet would require emergency lighting.