Emergency Power w/ generator & lighting control

Npstewart

Senior Member
Have the following set-up in a office (non required emergency power)

A group of lights in office. They are typically going to be fed from a emergency panel and the panel is fed from a transfer switch. Normally the transfer switch will get the power from the utility obviously.

I want the lights all to switch off via a timeclock or occ sensor, however I DONT want them to switch if the building on on the generator because I dont think its legal to switch emergency lights.

I could either:

Make a certain number of lights "night lights", that wont switch at all period so I always have (1) footcandle on the floor regardless.

(Or)

?

Maybe pull two circuits to the lights with some type of relay??? Anyone see another solution rather than having several night lights burning all day? Im looking at a ice-cube relay.

Please help.
 

charlie b

Moderator
Staff member
Let?s be clear about the terms being used. Your phrase ?non required emergency? is self-contradictory. If you are talking about egress lights, then they are required, and the term ?emergency? does apply. If instead you are talking about a night light for the convenience and safety of the security guard or any persons working late, then this is not the required egress lighting, and the term ?emergency? does not apply.

I have set up egress lights in such a way that the on/off switch at the entrance to a room controls all lights (the egress lights and the normal lights) in exactly the same way. That is, they all go on or off at the same time, based on what you do with the on/off switch. However, when the transfer switch is on its back up power source, that causes all the egress lights to be on at full brightness, regardless of the position of any on/off switch. But I was using a lighting relay panel to control all lights, and the switches provided low-voltage signals to that relay panel. The relay panel was programmed to recognize the status of the transfer switch, and to turn on the egress lights when it was on its back up source. I don?t know how to perform the same control actions without a relay panel.
 

Npstewart

Senior Member
I knew someone would say something about how I phrased that lol.

Charlie, I was thinking of using the system below (click the link). Specifically, I want to use the first diagram set-up. My only question is, I want to feed the lights from the "emergency power distribution panel" which will be fed from the transfer switch. Why does it how a "normal breaker" going to the light? My "normal breaker" is from the "emergency power distribution panel".

Thanks!

http://lightingcontrols.com/productcatalog/downloads/LCD_guides/LCD_guide_emergency_shunt_relay.pdf
 

charlie b

Moderator
Staff member
I have seen that type of product used. It works quite well. It doesn't have a normal breaker serving the light. Instead, it has a normal breaker serving a relay contactor. When normal power is available, the relay is energized, and its "b contact" will be open. That causes the on/off switch to be able to turn on and off the light. But if the normal power is lost, the relay will be deenergized, and its "b contact" will close. That causes the on/off switch to be bypassed, and the light will be on no matter what you try to do with the on/off switch.
 

Npstewart

Senior Member
Ok, so its really not to power the light, its really just a sensor. So on the floor plan I probably shouldn't show two circuit designations because that would be confusing.

I wonder how lighting relays I can have on one "normal" circuit.
 

charlie b

Moderator
Staff member
So on the floor plan I probably shouldn't show two circuit designations because that would be confusing.
Yes you should, for to fail to show both would be even more confusing. Just make it clear that one circuit powers the light and the other powers the relay.

 
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