EOLR relay for smoke detector


New Member
I'm replacing my 16 year old 4 wire smoke detectors.  They're tied into my HAI Omnipro 2 panel. The end of line smoke detector has an end of line 1k ohm resistor but doesn't have an EOLR relay.  I've never had a problem, just wanting to replace the old smokes.  Is their any over-riding reason to include a EOLR when I install the new smokes?
The relay detects any loss of power along the entire series of smoke detectors.  Without the relay, you could have a fault in the 12V wiring which would render the smokes inoperative.  You would have no way to know that they weren't working.  With the EOL relay, it will drop out on the loss of power and immediately trigger a fault alarm at the panel.  Having the relay is a life safety issue. 
Yes. Also 4-wire circuits must have EOL resistor and EOLR to satisfy code. 2-wire circuits do not need an EOLR since power and alarm circuit is on the same two wires.
I forgot to mention. Some smoke detectors have a built-in EOLR. It's possible that may be why you don't have an EOLR. What model of smoke do you have?