Can an End of Line Relay Cause Power Failure on a Zone?

Because 4-wire smoke detectors are Normally Open devices, and loss of power doesn’t change their state, power must be supervised with a separate relay, wired in series on the smoke loop. Fire zone logic lends itself to this process by indicating trouble on open circuit, and alarm on a short.

An End of Line Relay, or End of Line Power Supervision Relay, like the EOLR-1 is a simple device that closes when it receives 12 Volts DC power. If power is lost, the relay opens, causing a trouble on the fire zone the relay is wired in series with. Wire relay power from the last smoke in line on the 4-wire smoke loop. If the smoke loses power, the relay will open and cause a trouble condition on the 4-wire smoke zone. As long as the EOLR-1 is wired correctly, as shown above, it can not cause a power failure on a zone.

NOTE: In order to cut down on confusion with this wiring diagram, references to power reset for the smokes has been removed. 4-wire smokes latch on alarm, and will require that power to the zone be dropped momentarily in order to reset them afterward. For more that, click here.

Did you find this answer useful?

We offer alarm monitoring as low as $10 / month

Click Here to Learn More

Related Products

Honeywell VISTA-20P - Wired Alarm Control Panel
Honeywell VISTA-20P
Wired Alarm Control Panel
List Price: $213.00
Our Price: $139.99
Honeywell VISTA-15P - Alarm Control Panel
Honeywell VISTA-15P
Alarm Control Panel
List Price: $170.00
Our Price: $131.99
Taxons
System Sensor EOLR-1
Power Supply Supervision Relay
List Price:
Our Price: $18.99
Honeywell VISTA-20PSIA - Alarm Control Panel
Honeywell VISTA-20PSIA
Alarm Control Panel
List Price: $170.00
Our Price: $144.99
Honeywell VISTA-15PSIA - Alarm Control Panel
Honeywell VISTA-15PSIA
Alarm Control Panel
List Price: $170.00
Our Price: $131.99

Related Categories


Answered
Answered By