Electronic Alarms and Home Security Devices - 120V smoke detectors
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Robertakelseyjr
08-28-07, 09:57 AM
Can someone tell me how the common wire on the 120V smoke alarms communicates with other alarms ?
Is it a high voltage common or extra nutral thats NO or NC ???
NEC or NFPA must have a simple standard they use for all the manufacturers to go by so they are interchangable.
Is it a high voltage common or extra nutral thats NO or NC ???
NEC or NFPA must have a simple standard they use for all the manufacturers to go by so they are interchangable.
MrRonFL
08-28-07, 06:36 PM
It's a 9 volt signal (on _most_ models). That's why if you accidentally wire the high voltage to the interconnect it trashes the detectors, and why the interconnect works even with just the battery backup.