Emergency Lighting Circuit Through Lighting Contactor

[shroominator]

Hi all. Here is my situation.....

Remodeling a hospital floor. Emergency generator fed panel available. Feeding a number of 2x4, 3-lamp fluorescent fixtures in the corridors as emergency lighting. Here is where the fun part is:

The owner requires 2-level switching of the fixtures (inner lamp separately from outer lamps) with switching at the nurses station.

My solution - Run the outer lamp feeds through one mechanically held lighting contactor and the inner lamp feeds through another mechanically held lighting contactor. My thinking is, when power is lost and transfer to the generator occurs, the contacts will not open due to loss of coil voltage no matter how short of a time span that may be, as I think would happen with an electrically held lighting contactor. A mechanically held contactor requires a control signal to open the contacts doesn't it?

Is this an acceptable solution for my problem? I have seen elsewhere on this forum comments about contactors UL listed for emergency application, but I am unable to nail one down.

This one has me rubbing my head and I'm too bald for any more of that!

Thanks.

 

[iwire]

Typically we used normally closed electrically held contactors to switch emergency lights. If they fail they will normally fail to "on".

The other benefit is you supply the control circuit from the utility source so when the utility fails the control circuit goes away the contactor closes regardless of what position any switches where left. It is a requiment that emergency lighting come on when the power fails.

Using a mechanically held contactor on emergency lighting seems wrong to me, a very high likelihood of failure in the off position and it will not automatically close when the utility fails with out adding more complexity to the control circuit.


All that said, now you easily buy a relay just for this and they are listed for the purpose.

Here is one type but other manufacturers make them as well

http://www.wattstopper.com/Commercial-250-134/ELCU-100EmergencyLightingControl.html

 

[iwire]

Here are a bunch more

http://www.functionaldevices.com/lighting-controls/ul924.php

 

[RobbieR]

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

However, I really dig these. But might be too expensive for this application...
http://www.bodine.com/downloads/specs/GTD.spec.(std).L4100004.pdf

 

[roger]

Hi all. Here is my situation.....

Remodeling a hospital floor. Emergency generator fed panel available.

Is this panel a Critical Branch panel or a Life Safety Branch Panel?

Feeding a number of 2x4, 3-lamp fluorescent fixtures in the corridors as emergency lighting. Here is where the fun part is:

The corridor lights will most likely be on the Life Safety Branch and 517.32(A) will be applicable

The owner requires 2-level switching of the fixtures (inner lamp separately from outer lamps) with switching at the nurses station.

As mentioned in the 517.32(A) FPN or IN, see NFPA 101 7.8 specifically 7.8.1.2, this requires egress illumination to be continuous during the time the facility is occupied, the required amount of illumination may not allow for switching these corridor lights at all.

Roger

 

[shroominator]

Is this panel a Critical Branch panel or a Life Safety Branch Panel?

The corridor lights will most likely be on the Life Safety Branch and 517.32(A) will be applicable

As mentioned in the 517.32(A) FPN or IN, see NFPA 101 7.8 specifically 7.8.1.2, this requires egress illumination to be continuous during the time the facility is occupied, the required amount of illumination may not allow for switching these corridor lights at all.

Roger

These are things I must check on. Will post more info soon.

Thanks,

Craig

 

[shroominator]

More Information

More Information

Here we go.

Keep in mind that this is an old hospital. This is a nearly complete gut job of the Fifth floor.

It appears, based on panel labels (EC5A & EC5B), that at one time these were meant for Critical branch panels. Existing loads included patient room recepts., phone/data rooms, some lighting and a few fans of one kind or another. Then it seems to have been bastardized into a mutant Life Safety/Critical combo panel, as it now has multiple breakers for fire alarm and corridor lighting. I now realize this needs corrected with a couple new panels for Critical Branch use, leaving the existing to serve fire alarm, egress lighting, PA, etc... (acceptable loads) as Life Safety panels. Makes more sense to leave the fire alarm circuits in place than to get into all that.

As to the emergancy lighting and two-level switching. Think I'll nix the whole idea since I can't guarantee both circuits (inner & outer lamps) won't be extinguished at the same time. Unless I put the inner lamp ballast on an unswitched hot, probably a code against that. Better come up with something else.

 

[Smart $]

...

As to the emergancy lighting and two-level switching. ...

FWIW, 3-lamp, 2-balast fixtures are capable of three-level lighting:

1. One lamp,
2. Two lamps, and
3. All three lamps.

 

[BullsnPyrs]

Many emergency lighting circuits also serve as night lights and remain unswitched. One option might be to let the Nurses station switch the two lamp ballast and leave the one lamp ballast hot 24 Hours.

 

[shroominator]

Many emergency lighting circuits also serve as night lights and remain unswitched. One option might be to let the Nurses station switch the two lamp ballast and leave the one lamp ballast hot 24 Hours.

Sounds like a plan to me. Just received owners switch "zoning" mark-up. He had something else in mind, certainly wasn't convenience. The circuiting changes are enough to eliminate the need for contactors entirely.

I do appreciate all the comments and guidance though.

Thanks again,

Craig

 

[cadpoint]

The rules change because your working a hospital!

One needs to address the service accordingly. It doesn't matter what is implied by the owner it's what needs to be addressed as a circuit or service due to it's application!