Thread Starter


Hello all: Please get me URLs of smoke detectors which are PLC compatible.. Best regards Santhiraj

Ramer-1, Carl

All simple smoke detectors are "PLC compatible" in that they provide a state change of a switch contact on alarm. Some are designed for 2 wire circuits and some for 4 wire circuits. There are also some which can provide analog or pseudo-analog "level" signals. To further complicate matters, there are at least three approved types on the market, photoelectric, ionization and dual technology which combine both previous techniques. Two wire models expect power on those two wires (typically in the USA it's 12 or 24 volts DC), and are supervised by a control panel. The 4 wire versions expect power on two wires and provide state changes on the other two. I'm curious about using a smoke detector with a PLC. Is it for a Fire Alarm system? Local fire codes may not allow using PLC's for that purpose. We have to use UL/NFPA approved devices on UL approved systems for fire alarms here. I'm not sure any PLC's are UL (or equivalent) rated for Fire Alarm/life safety compliance. Here are a few URL's to help your search: tectors/psd7155photoelectricsmokedetectors.htm Carl Ramer Protective Systems Design Space Gateway Support, Inc. Kennedy Space Center, Florida Unsponsored personal posting. None of the above products is approved or endorsed by NASA or Space Gateway Support.