EM Lighting Relay

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These type of relays are used when a lighting load is switched.

Your post stated that these fixtures are unswitched.... why do you need the relay? Are they on an emergency circuit already?

Can you explain the circuit better?

Depending on how the circuit is wired and switched you may need 1 or may need 8.

Maybe I'm missing something....
 
Joe Villani said:
These type of relays are used when a lighting load is switched.

Your post stated that these fixtures are unswitched.... why do you need the relay? Are they on an emergency circuit already?

Can you explain the circuit better?

Depending on how the circuit is wired and switched you may need 1 or may need 8.

Maybe I'm missing something....
Click to expand...

They are on EM ckt...ill check notes again in morning. Thanks
 
Here is the note.
Provide and install UL 924 bypassrelays to allow for switching of emergency fixtures. Upon loss of normal power,fixtures shall illuminate to full brightness regardless of switch position.Coordinate in field.
 
I would put 1 relay but you would have to run the fixtures that are designated emergency on 1 switch leg and the normal lighting on another switch leg. The two switch legs would parallel off the switch or motion sensor.

This would have to be communicated to the feild as at 150 a peice the cost for individual relays would add up quick.
 
mstrlucky74 said:
Here is the note.
Provide and install UL 924 bypassrelays to allow for switching of emergency fixtures. Upon loss of normal power,fixtures shall illuminate to full brightness regardless of switch position.Coordinate in field.
Click to expand...
These relays are typically used in emergency lighting systems where there is not a full blown UL listed emergency lighting control system and you just want a compliant way to have a user accessible switch to control lighting that is also part of the emergency lighting. All the relay does is shunt out the switch so that in the event of a power failure the E. lights will come on even if the switch is off. It should be noted that this relay is not a "transfer switch" but rather just a means to shunt around the switch. It also must be a listed relay for this purpose, not just an off the shelf relay. See Art. 700.25 in the 2014 edition.
It would also help you to understand that this relay option came to be as a result of energy conservation. Historically most buildings that used a genset for emergency lighting had to burn the E. fixtures 24/7 because, as a general statement, local manual switches were not permitted as the occupants could be left in the dark in a power failure if the switch was off. Art. 700.25 gives you the ability to have the E. fixtures off if they are not needed but yet automatically come on in a power failure.
 
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