Emergency Lighting where the IBC meets the NEC

[jar546]

More emergency lighting! For the building inspectors out there. Here is an excerpt from the NEC on this subject. Are you coordinating your building and electrical inspectors for these systems????

700.16 Emergency Illumination. See related ULEmergency illumination shall include all required means of egress lighting, illuminated exit signs, and all other lights specified as necessary to provide required illumination.

Emergency lighting systems shall be designed and installed so that the failure of any individual lighting element, such as the burning out of a lamp, cannot leave in total darkness any space that requires emergency illumination.



Where high-intensity discharge lighting such as high- and low-pressure sodium, mercury vapor, and metal halide is used as the sole source of normal illumination, the emergency lighting system shall be required to operate until normal illumination has been restored.



Exception: Alternative means that ensure emergency lighting illumination level is maintained shall be permitted.



High-intensity discharge (HID) fixtures take some time to start once they are energized. Therefore, if HID fixtures are the sole source of normal illumination in an area, the Code requires that the emergency lighting system operate not only until the normal system is returned to service but also until the HID fixtures provide illumination. This may require a timing circuit, photoelectric monitoring system, or the equivalent.

 

[jar546]

OK 5 days and no takers. I will have to break this down since I think it is important.

If an area of lighting, such as an area served by HID's that takes a long time to turn on and provide illumination suddenly goes out because of a loss of power, the EL in that area need to come right on and they usually do.

The problem exists when power returns to that circuit, the emergency lights go right back off immediately BUT the area is still in the dark while the HID's are heating up.

So I know we all check EL systems by having the power turned off to the affected area of lighting, BUT, do we notice the time it takes the HID lights to come back on when the EL's go out? That is what this section of the NEC addresses. I see how this is integrated in with the requirements of the IBC and we need to pay attention to this, even if you are not an electrical inspector.

 

[Inspector 102]

Although it might take the lighting awhile to reach full intensity, are the lights providing the minimum 1-footcandle at the walking surface? I have never checked even though I do have a light meter. If I get the chance I will have to get the meter out and scare the electrician by doing another test prior to approval. Good point to watch for. I have enough trouble with the exterior landing requirement, this will really spin their head.

 

[steveray]

I know we have gotten this to work using additional wiring controls, but the specifics escape me right now.....We are looking at this and have no choice but to coordinate with a staff of 2 inspectors for everything....

 

[Oldfieldguy]

If anyone wants an example of what happens when HID lamps are de-energized in a crowded venue, go find a replay of this year's Super Bowl.

 

[rnapier]

Here is an article that deals with HID and emergency lighting. Applying (HID) lamps to emergency lighting | content content from Electrical Construction & Maintenance (EC&M) Magazine

 

[rnapier]

Also here the building and electrical inspectors work closely with each other to ensure compliance with 700.16 and 700.12 where the emergency lightings needs to be on the circuit feeding the general lighting with an exception.

 

[TJacobs]

Someone needs to come up with an adjustable delay circuit within emergency lighting fixtures/systems.