Roger Moderator
Tom, it was my experience with these older systems that this was always a dedicated zone/circuit for the tamper(s)and flow, the trouble signal for this zone was nonsilenceable (I don't think that's a word) and was annunciated and monitored as to being a tamper, the PIV's were done the same.
Roger
Roger
I still don't see how the central, remote, or proprietary signal receiving station would differentiate between some failure of the alarm systems wiring and a valve tampering event. The UL standard governing UL listed Central Stations would require distinct signals. For a trouble signal you call out the alarm maintenance technician. For a tamper signal you dispatch security and in some cases notify the on duty Fire inspector or deputy fire marshal. Remote Stations such as Fire Department Communications offices are particularly allergic to receiving and handling any form of trouble signal but may require that a valve tamper be signaled to them. Off premise proprietary stations need to know whom to notify. Central Stations will of course accept any signal you pay them to handle but the service provided must be acceptable to the AHJ. If your talking about a local only system then whoever is responding to the signals can sort that out.
I have worked in my youth for several fire departments as a dispatcher and none of them would want to receive a signal that did not differentiate between alarm system breakdown and valve tampering. In such a case the trouble signal would not be forwarded by a central or proprietary station. Trouble signals would not have been acceptable for connection to the fire departments remote station receiving apparatus accept as discreet signals and, in the case of discreet signals, trouble signals would be received only by permission as trouble and normal with no signal action taken other then a check that the responsible had established a fire watch.
The dual resister arrangement that the OP described would provide a distinct signal that could be handled under any arrangement of off premise receiving. Using a tamper switch to open the supervision would bring on the signal processing problems I have laid out. As I already said in a local only system it would be perfectly acceptable and if neither the trouble or the tamper signal has to reach the fire department then a combined signal would work for off premise monitoring accept to a UL listed Central Station.
--
Tom Horne
"This alternating current stuff is just a fad. It is much too dangerous for general use." Thomas Alva Edison
[This message has been edited by tdhorne (edited 08-08-2006).]
