Switching existing egress lighting

[Steve-R]

I have an existing application where fluorescent egress lighting has been installed (with a normal ballast and an emergency/battery ballast). This lighting is not switched. The owner would like to switch the egress lighting with the normal fixtures. Is there any code requirement that would not allow the egress lighting to be switched from the nearest "normal" fixture, i.e., bring a switched wire from the nearest normal fixture to each normal ballast in the egress fixtures? The emergency/battery ballast would remain connected to an unswitched source (from the same circuit as the "normal" fixtures), so in case of normal power failure, the egress lights will come on.

My main concern is running a neutral and unswitched hot into the fixture in one conduit, then in additon to a switched hot with no neutral in another conduit into the same fixture. I've been looking everywhere I can think of in the NEC, and haven't come across anything. Am I missing something, or overthinking this?

 

[iwire]

My main concern is running a neutral and unswitched hot into the fixture in one conduit, then in addition to a switched hot with no neutral in another conduit into the same fixture.

That will very likely be a violation of 300.3(B)

 

[Steve-R]

I did notice 300.3(B) before asking, but didn't think a neutral ALWAYS had to go everywhere with a hot or switched leg. For instance, in a lighting circuit, does a neutral always have to travel to the switch, or to every switch in a three-way circuit? I take it my assumption is incorrect?

With 300.3(B) and my original scenario in mind, if the emergency ballast was on a separate circuit (breaker) than the normal ballast, would there be any violation? You would have one conduit with a neutral/ground/unswitched hot coming from one circuit, and a second conduit with a neutral/ground/switched hot from a separate circuit entering the same fixture. In that case, what would prevent the normal and emergency ballasts from energizing the lamps at the same time, if normal power was lost to the emergency ballast but not the normal ballast?

Thanks for the help.

 

[DaveTap]

As far as wiring... the 2 ballasts might as well be seperate fixtures or consider them like 2 lamps on different switches or circuits, no wires are shared... they're just both in the same box.

 

[Steve-R]

That will very likely be a violation of 300.3(B)

Am I correct that it would not be a violation if both conduits entering the fixture were from the same circuit, and both conduits had hot/neutral/ground wires? One would be switched and go to the normal ballast, one would be unswitched and go to the emergency ballast. I don't think that would violate 300.3(B) or anything else I'm aware of, and seems safer than feeding the emergency ballast and normal ballast from separate circuits.

 

[iwire]

I don't see a violation with it on the same circuit or even different circuits, and no the neutral does not have to run to the switch...

if the neutral is not used...as in a switch leg.

I may be misunderstanding his situation but it does not sound like a 'normal' switch leg to me.

It sounds like one hot and neutral from one raceway will be supplying current to one part and a hot coming from another raceway will be supplying current to another part using the neutral from the other raceway. If that is the case it is a 300.3(B) violation

What ever conductors run in the same raceway or cable must cancel each other out or inductive heating may happen

 

[iwire]

Am I correct that it would not be a violation if both conduits entering the fixture were from the same circuit, and both conduits had hot/neutral/ground wires?

That can cure the 300.3(B) but may end up violating 310.4

 

[jtester]

.....With 300.3(B) and my original scenario in mind, if the emergency ballast was on a separate circuit (breaker) than the normal ballast, would there be any violation? You would have one conduit with a neutral/ground/unswitched hot coming from one circuit, and a second conduit with a neutral/ground/switched hot from a separate circuit entering the same fixture. In that case, what would prevent the normal and emergency ballasts from energizing the lamps at the same time, if normal power was lost to the emergency ballast but not the normal ballast?

Thanks for the help.

If I understand your post correctly, you have normal lighting on 1 circuit, and emergency on another. That is likely a violation of 700.12(F) which requires the emergency to be on the same circuit as normal lighting unless the immediate space is served by 3 or more circuits.

You might want to check 700.12.

Jim T

 

[benaround]

SteveR,

My main concern would be if someone hurt themself after you altered the

original lighting plan, are you willing to risk that responsibilty to save the

owner a few dollars??

IMO, the reason the light is not switched is because it's not supposed to be

switched, the exact "codes" I do not know. I wrote this in case it never

entered your mind, don't take this the wrong way as I'm looking out for you.

 

[steve66]

We frequently specify emergency lights (with a battery ballast) switched on and off like you mentioned. However, IMO, the correct way to do this is to run the hot and neutral from the panel. Then the hot splits off to the switch, and then the switch wire comes back to where it split off at. Then all 3 wires (hot, switched, and neutral) run to each emergency fixture, and 2 wires (switched and neutral) run to each normal light.

I would think you should be able to get the wiring the same way by taking the switched neutrals out of a common jbox.

So the key point is all three wires (hot, switched, and neutral) run into the light in the same whip or conduit.

 

[W6SJK]

Check the wording of the appropriate BUILDING code. I wish I had one with me to check. Typically means of egress must be lighted to 1fc any time the building is occupied. Supplying a switch may not meet that requirement, or set the owner up for problems later. Just my 0.01999

 

[steve66]

Check the wording of the appropriate BUILDING code. I wish I had one with me to check. Typically means of egress must be lighted to 1fc any time the building is occupied. Supplying a switch may not meet that requirement, or set the owner up for problems later. Just my 0.01999

I have been using that detail (of switching emergency lights) since I started my current job, so I actually claim I have ever searched codes to verify it is acceptable.

However, I also don't see any difference between switching em. lights and using frog eyes. They also only come on when the power fails.

Steve

 

[W6SJK]

However, I also don't see any difference between switching em. lights and using frog eyes. They also only come on when the power fails.

Architects hate bug eyes

 

[jtester]

I have been using that detail (of switching emergency lights) since I started my current job, so I actually claim I have ever searched codes to verify it is acceptable.

Steve

If you are governed by the International Series of Codes, particularly the IECC, you will find that exterior lighting is supposed to be automatically controlled, a light switch without PE's or time clocks would be a violation.

"805.2.3 Exterior lighting controls. Automatic switching or
photocell controls shall be provided for all exterior lighting
not intended for 24-hour operation. Automatic time
switches shall have a combination seven-day and seasonal
daylight program schedule adjustment, and a minimum
4-hour power backup"

You can "switch" it, but not the way most of us are used to.

Jim T

 

[W6SJK]

Jim, He's talking about indoor lighting.

Steve

 

[benaround]

Steve,

Actually we are talking about both, egress includes the outdoor part to be

illuminated, and EM of course is inside.

IMO this fixture is doing two jobs, it's not just about the power going out, it

is also about people leaving the building after dark.