2 Wire Smoke Detector Compatibility

[Leo]

2 Wire Smoke Detector Compatibility

All smoke detectors do not work on all alarm control panels, this is an obvious statement but what is not obvious is which detectors will work on which panel.

The reason is the different electrical characteristics between smoke detectors and control panels. UL has a form“COMPATIBILITY DATA FORM FOR CONTROL UNIT AND TWO WIRE SMOKE DETECTORS” which manufactures use to get their smokes and panels cross listed.

Only 2 wire smoke are of concern this is because unlike a normally open device that shorts on an alarm, a 2 wire smoke is powered via the control panel and when it goes into alarm it does not short, it draws more current (Alarm Current). The smoke detector needs to be compatible with the control sets volt (12 or 24). But it also needs to draw the right amount of current in standby and in alarm.

Other concerns are Relay Base compatibility. Some systems are designed so when a smoke goes into alarm the voltage reverses and a sounder within the smoke sounds.
Along with the smoke being listed with a panel, there is also a maximum number of smoke detectors per circuit. Also in many cases as part of the Compatibility listing for the control panel, the manufacturer say you cannot mix different smokes on the same circuit, which from a maintenance standpoint is a bit of a joke.

Knowing if a smoke detector is cross listed with a panel when replacing a smoke due to maintenance is one thing, which can be done with ESL Smoke – Detector Compatibility Index, but replacing the control panel is another. The control must be cross listed with the smokes from the initial installation. This limits the control panels that can be used as a replacement.
System Sensor has a GREAT tool for checking (2-wire Compatibility) with their smokes, it will tell you the zone model ie: EST3 3-IDC 8/4 and the EOL resistor, which on its own is a great tool. EOL Resistor of every panel, great tool

 ESL Smoke – Detector Compatibility Index http://www.interlogix.com/resources/fir ... _10-04.pdf
 Notifier Smoke – Detector Compatibility Index http://www.notifier.com/literature/15378.pdf
 System Sensor – Smoke Detector Compatibility Index http://www.systemsensor.com/2wirecomp/
 Fire-Lite – Smoke Detector Compatibility Index http://www.firelite.com/manuals/15384.pdf