Always On "Night Lights"

[Keri_WW]

Are a certain number of lights required to be "always on" to pacify the egress requirements of NFPA 101? I can't seem to find anything in there that explicitly requires these.

I'm not talking about emergency backup or anything, just an unswitched light every so often down a corridor and other spaces.

Please give me some references.

Thanks,
Keri :grin::grin:

 

[iwire]

I know we routinely shut down all lighting and even exit signs in unoccupied buildings (big box stores, office buildings) but the egress lighting and exits are arranged to automatically come back on if there is a power failure or the fire alarm system goes into alarm regardless of the building being empty or not.

 

[Keri_WW]

When I first started designing, I was told that a certain number of lights had to be always on in the case that someone switched the lights off with other people in the space. I'm starting to wonder whether or not this is an actual requirement or not. I can't seem to find anything that indicates that it is.

 

[charlie b]

We have done a number of large lab buildings lately. In the corridors, we have been putting every third or fourth luminaire on an unswitched circuit. That is, there is no way to turn it off, other than with the circuit breaker. The intent is that they stay on 100% of the time. Our lighting designer (who is not at his desk at the moment, so I can't ask him for a code reference) selects the "night lights" on the basis of keeping a minimum value of candlepower at the floor level. I suspect there is a relevant code requirement, and that it originates with the Illuminating Engineering Society standards.

These "night lights" are always powered by the emergency distribution system, so that if the building lost normal power they would be included in the emergency lighting that would be turned on within 10 seconds. We put "switched" emergency lights (i.e., can be turned on and off or can be controlled by a LV lighting control system, but are forced on when the emergency diesel is on line) in offices, labs, and classrooms, and only put the "night lights" in corridors.

 

[dicklaxt]

Once again from memory ,,,if an area(rooms) if occupied 24/7 it must have egress lighting,hallways must have lighting as Charlie B stated or battery wall packs, bathrooms may also have a requirement,,,,,,,,,,,,,,,,,,,some places even require directional escape/egress arrows out of large areas and hall corridors.

I think the footcandle minimums is .2 to .5 but that may be an industrial requirement,not sure off the top of my head.It is nothing more than stumble lighting.

We always ued 10% of fixture count to be on emergency source,but this requirement can be client spec as well.

Its covered under OSHA Egress Requirements.

dick

 

[charlie b]

I spoke with my lighting designer, and discovered that I had been thinking about things backwards. It is not a matter of a rule that requires a certain minimum number of lights, or a certain minimum footcandles, be turned on at all times. Instead, he explained it to me in this way:

• There is a rule that requires the exit pathways to be illuminated, in the event that normal utility power is lost (i.e., ?egress lighting,? which is required to be powered by the ?emergency distribution system?).
• There used to be a rule that these lights could not be switched.
• However, they have relaxed that rule, and allowed the egress lights to be controlled by on/off switches, so long as they would all come on, if normal utility power is lost. This was an energy conservation measure.
• We have made the design decision to leave some of the egress lights on at all times, for the benefit of night workers or security personnel, and to switch the others.
• In the near future, a change to the state energy code will require that all lights, including the egress lights, be ?swept off? by the control system, when there is nobody working in the area (i.e., based on occupancy sensors). Here again, if utility power is lost, the egress lights will be turned on within ten seconds. When that code takes effect, we will no longer be able to leave any lights on 24/7/365.

 

[justinaway1]

Is this an IES rule or osha then? Does this apply to stairwells? Is there a requirement for electrical room illumination, I couldnt find anything in NEC or UBC.

 

[IslandSparky]

Is this an IES rule or osha then? Does this apply to stairwells? Is there a requirement for electrical room illumination, I couldnt find anything in NEC or UBC.

It used to be that you couldn't switch fire stair lights, but energy code has pushed it to the point that you can put half the lighting on occupancy sensors. I personally consider that an unsafe practice, as applied in practice; it takes too long for the light to come on, and poses a tripping hazard to "back-light" the stairs.

If you could (economically) dim the stair lights down to 10%, and go to full bright on occupancy sensor, I would be more supportive of the practice.

The illumination level for egress of 1fc minimum really makes it hard when we get to 10' spacing of lights. Fixture cutoff and effective range end up requiring half the lights to be on, resulting in almost 25fc in the exit path.

Rationalizing the requirements, I think with a time clock system that has phone override, at least one light in the space should stay on at least 10 minutes after the general sweep. Best solution is for everything to drop to 10% output, then switch off 25% of the lights every 2-3 minutes.

I worry about the liability in complying with current energy codes here in California.

 

[Keri_WW]

So does anyone have an actual code reference related to this?

I am working on a dormitory and need to know if there is a requirement for the corridors.

 

[USMC1302]

Keri:
I think NFPA 101 does address it, and since this is a dormitory I would think it would always be considered occupied. The corridors would be an "egress path" and would have to maintain 1 foot candle of illumination measured at floor level. Maybe section 7.8.1.3 in NFPA 101 and UBC 1003.2.9.1?? I can't see how you could not use nightlights in your situation

 

[charlie b]

Keep in mind that the "egress lights" are required to be on in the event that the normal utility power is lost. That does not mean that they have to be on all the time. But unless you have a low voltage lighting control system that can override all other controls, sensors, and switches, and turn on all egress lights when the power system switches to its emergency source, then I don't know how to avoid leaving them on at all times.

 

[iwire]

But unless you have a low voltage lighting control system that can override all other controls, sensors, and switches, and turn on all egress lights when the power system switches to its emergency source, then I don't know how to avoid leaving them on at all times.

That used to be more of an issue now many manufactures are making small 'Emergency Shunt' relays that are listed to take care of the problem.

'Watt Stopper' and 'Functional Devices' both have them, here is another brand.


http://www.lightingcontrols.com/productcatalog/overview.asp?p=emergencyshunt


As a side note I would be very surprised if any code requires any lights to remain on in an unoccupied building on utility power, that would serve no purpose and waste resources besides increasing the mantanence costs for those fixtures.

 

[WorkSafe]

NFPA 101:

7.8.1.3* The floors and other walking surfaces within an exit and within the portions of the exit access and exit discharge designated in 7.8.1.1 shall be illuminated as follows:


(1)During conditions of stair use, the minimum illumination for new stairs shall be at least 10 ft-candle (108 lux), measured at the walking surfaces.

(2)The minimum illumination for floors and walking surfaces, other than new stairs during conditions of stair use, shall be to values of at least 1 ft-candle (10.8 lux), measured at the floor.

(3)In assembly occupancies, the illumination of the walking surfaces of exit access shall be at least 0.2 ft-candle (2.2 lux) during periods of performances or projections involving directed light.

(4)* The minimum illumination requirements shall not apply where operations or processes require low lighting levels.

7.8.1.2 Illumination of means of egress shall be continuous during the time that the conditions of occupancy require that the means of egress be available for use, unless otherwise provided in 7.8.1.2.2.

 

[david luchini]

Keep in mind that the "egress lights" are required to be on in the event that the normal utility power is lost. That does not mean that they have to be on all the time.

I don't think this statement is correct with regards to NFPA 101. The means of egress should be illuminated continuously "during the time that the conditions of occupancy require that the means of egress be available for use." For a dormitory, I'd say this would have to be 24 hrs.

"Emergency lighting for means of egress" is only required in the event that normal utility power is lost.

 

[DetroitEE]

That used to be more of an issue now many manufactures are making small 'Emergency Shunt' relays that are listed to take care of the problem.

'Watt Stopper' and 'Functional Devices' both have them, here is another brand.


http://www.lightingcontrols.com/productcatalog/overview.asp?p=emergencyshunt


As a side note I would be very surprised if any code requires any lights to remain on in an unoccupied building on utility power, that would serve no purpose and waste resources besides increasing the mantanence costs for those fixtures.

That's a pretty clever little device.

We've used devices called Generator Transfer Devices by Bodine, which basically do the same thing, except they allow you to control both normal and emergency lighting in a room with one switch, as opposed to two separate switches.

 

[iwire]

That's a pretty clever little device.

We've used devices called Generator Transfer Devices by Bodine, which basically do the same thing, except they allow you to control both normal and emergency lighting in a room with one switch, as opposed to two separate switches.

I have seen those as well.