Fail Safe Relay

Talome34

Member
Location
Tennessee
This is probably an easy question for you guys but here goes:

Lets say I have two lights controlled by one vacancy sensor/single pole switch. One light is normal and the other is emergency egress. In the case of a power outage, full power must be applied to the egress light. The product to accomplish this is an EELP RLS.

I am assuming there would need need to be a 2 circuit power pack for my normal and emergency circuit? But where exactly does the above mentioned relay come into play? How would it be wired?

Thanks guys in advance, if you need anymore info, I’ll be glad to add it.
 

Strathead

Senior Member
This is probably an easy question for you guys but here goes:

Lets say I have two lights controlled by one vacancy sensor/single pole switch. One light is normal and the other is emergency egress. In the case of a power outage, full power must be applied to the egress light. The product to accomplish this is an EELP RLS.

I am assuming there would need need to be a 2 circuit power pack for my normal and emergency circuit? But where exactly does the above mentioned relay come into play? How would it be wired?

Thanks guys in advance, if you need anymore info, I’ll be glad to add it.
There is a diagram in your thread, and basically, the EELP is a listed emergency transfer switch (ETS), I assume. I didn't look it up but this is how they all work. It receives, emergency hot and neutral. It receives normal power hot, neutral and switch leg. On the output side you have a switch leg and a neutral. (proper grounding for all assumed) Under normal operation the ETS senses normal power from the normal power hot. It routes power from the normal switch leg and normal neutral to the output. So switch on, switch off affects the lights. When normal power goes down, the ETS sense it and switches to route power from the emergency power source both hot and neutral to the output. Normally there is a barrier that has to be installed in the box for the ETS to keep the emergency and the normal power separate per code.
 

Talome34

Member
Location
Tennessee
There is a diagram in your thread, and basically, the EELP is a listed emergency transfer switch (ETS), I assume. I didn't look it up but this is how they all work. It receives, emergency hot and neutral. It receives normal power hot, neutral and switch leg. On the output side you have a switch leg and a neutral. (proper grounding for all assumed) Under normal operation the ETS senses normal power from the normal power hot. It routes power from the normal switch leg and normal neutral to the output. So switch on, switch off affects the lights. When normal power goes down, the ETS sense it and switches to route power from the emergency power source both hot and neutral to the output. Normally there is a barrier that has to be installed in the box for the ETS to keep the emergency and the normal power separate per code.
Makes perfect sense to think of it as a mini ATS. It gets both sources and the switchleg. In case of a normal power failure, it will transfer to emergency. And I guess the switch side of the ATS would open to prevent backfeeding to the switch itself.
 

Strathead

Senior Member
Makes perfect sense to think of it as a mini ATS. It gets both sources and the switchleg. In case of a normal power failure, it will transfer to emergency. And I guess the switch side of the ATS would open to prevent backfeeding to the switch itself.
It actually IS an automatic transfer switch that also must be listed for use as emergency article 700 equipment.
 
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