night and emergency lighting
- Thread starter mrdiode
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ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: night and emergency lighting
They can be switched, as long as they come on automatically when the power goes off.
I better clarify. The power source for the emergancy ballast cannot be switched, but the regular ballast can be.
[ May 16, 2005, 12:45 PM: Message edited by: ryan_618 ]
They can be switched, as long as they come on automatically when the power goes off.
I better clarify. The power source for the emergancy ballast cannot be switched, but the regular ballast can be.
[ May 16, 2005, 12:45 PM: Message edited by: ryan_618 ]
Re: night and emergency lighting
My opinion, the EE "just made a mistake", but I would absolutely contact him for clarification....and go over the print with a magnifing glass (including conduit and feeder sizes matched to CBs)...a minor issue like EML and NL may not cost you much in terms of time and material, but a major blunder like no EGC in an undersized conduit or mismatched conductor size (and therefore conduit size) and OCP will.
The EM lighting should not be switched. The NL might be switched according to customer's request(on a time clock for example).
My opinion, the EE "just made a mistake", but I would absolutely contact him for clarification....and go over the print with a magnifing glass (including conduit and feeder sizes matched to CBs)...a minor issue like EML and NL may not cost you much in terms of time and material, but a major blunder like no EGC in an undersized conduit or mismatched conductor size (and therefore conduit size) and OCP will.
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
Re: night and emergency lighting
Ryan: Do you think that this proposed design would create violation?
I think the emergency ballast can be switched. I agree with your opening statement:
For example, I am working on a small county jail project. Our lighting designer has egress lights and night lights in the sleeping areas. The night lights will be on forever. The egress lights in the dorms can be turned off at night. But there will be an auxiliary contact in the ATS, wired to override the on/off switch. Thus, if the utility power is lost, when the ATS transfers power to the generator all egress lights will come on.
Ryan: Do you think that this proposed design would create violation?
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: night and emergency lighting
I agree with your instalaltion Charlie, because what you describe would be an emergancy system. What I was trying to explain, poorly perhaps, is that you can't swicth the ballast of unit equipment.
I agree with your instalaltion Charlie, because what you describe would be an emergancy system. What I was trying to explain, poorly perhaps, is that you can't swicth the ballast of unit equipment.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Re: night and emergency lighting
I think that the question here is what is the real function or requirement for a night light. Is it simply convenience lighting or is it a required light designed to keep someone from have to navigate in the dark if the lights were turned off? If it is a required light than I don't see how it can be switched.
[ May 16, 2005, 06:01 PM: Message edited by: infinity ]
I think that the question here is what is the real function or requirement for a night light. Is it simply convenience lighting or is it a required light designed to keep someone from have to navigate in the dark if the lights were turned off? If it is a required light than I don't see how it can be switched.
[ May 16, 2005, 06:01 PM: Message edited by: infinity ]
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
Re: night and emergency lighting
It's a question of "required by what." In my case, the requirement came from the owner (wanted the guards to be able to count bodies in beds). But I don't think the requirement (or the prohibition) for switching night lights would come from the NEC. It's not an electrical safety issue, nor is it a life safety (i.e., egress lighting) issue.
It's a question of "required by what." In my case, the requirement came from the owner (wanted the guards to be able to count bodies in beds). But I don't think the requirement (or the prohibition) for switching night lights would come from the NEC. It's not an electrical safety issue, nor is it a life safety (i.e., egress lighting) issue.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Re: night and emergency lighting
Well, it seems rather odd to me to have an area that is completely black when the normal power is present and then to have emergency lights illuminated when the normal power goes off as in a power failure. Why would those lights be needed during a power failure and not when some flipped off the light switch?
Well, it seems rather odd to me to have an area that is completely black when the normal power is present and then to have emergency lights illuminated when the normal power goes off as in a power failure. Why would those lights be needed during a power failure and not when some flipped off the light switch?
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: night and emergency lighting
As far as someone turning the lights off goes, well, I guess you can't address everything in the code!
I think it is a matter of energy conservation. There is no reason to require lights to be running 100% of time, even when the buildinging is completley unoccupied.
As far as someone turning the lights off goes, well, I guess you can't address everything in the code!
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Re: night and emergency lighting
I'm just thinking of the many office buildings I've seen where they have EM/NL fixtures. These fixtures are on 24/7 for night light illumination. Since many of these buildings have lighting control systems it is highly possible that someone could be in their office or in the can when the lights go out. So these spaces are designed with night lights for that reason. Also these fixtures have a battery back up so that they will also illuminate as an EM fixture during a power failure.
I'm just thinking of the many office buildings I've seen where they have EM/NL fixtures. These fixtures are on 24/7 for night light illumination. Since many of these buildings have lighting control systems it is highly possible that someone could be in their office or in the can when the lights go out. So these spaces are designed with night lights for that reason. Also these fixtures have a battery back up so that they will also illuminate as an EM fixture during a power failure.
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