Members. Adding to others comments the distinction pursuant to NFPA-72 is that of a supervisory signal versus a trouble signal, the latter indicating a circuit fault.
Since these circuits (pathways) are required to be monitored for integrity (supervised) it's easy to wire a tamper in that causes a signal that looks like a wire break (trouble) but this would be incorrect. Wire faults are trouble causing, Valve position is supervisory causing. To this very day installers are still miswiring tamper switches such that they are trouble causing and not supervisory causing. Also as Ken pointed out 20 tamper limit on IDC circuit however keep in mind that some code sections require distinct Annunciation, i.e. IBC addressable systems, multi story buildings. On Jul 5, 2017 4:29 PM, Parsley Consulting <[email protected]> wrote: > > Owen, > > if the fire alarm and/or sprinkler monitoring system is addressable the PIV > on the backflow valves could be designated with an address unique from that > on the PIV, all three of which would send an identifiable signal back to the > panel. The signal does not have to be unique to one valve. > > What -72 is telling you quite clearly in the explanatory text from the > handbook is that all - repeat ALL - of the tamper switches could be on the > same circuit, provided there were no more than 20 such devices on that > circuit, as the activation of any one of those switches must produce a > supervisory signal at the panel. This would include: > Activation of a common supervisory signal indicator > Activation of an audible supervisory signal > Display/print out a change of status > Transmit a supervisory signal to the supervising station > Actuate a graphics system - display/floor map. > > The above are suggestions from a typical input/output matrix as described in > NFPA 72, A14.6.2.4. > > I hope that clears it up. > > Ken Wagoner, SET > Parsley Consulting > 350 West 9th Avenue, Suite 206 > Escondido, California 92025 > Phone 760-745-6181 > Visit our website > On 07/05/2017 12:21 PM, [email protected] wrote: > > Ok, so the tamper switch on the PIV sends a unique signal, different from the > tamper on the DCV that it is connected to in series? It should indicate the > PIV tamper is moving at the panel? I just assumed a unique wire ran back to > the panel for each tamper. > > Sent from my iPhone > > On Jul 5, 2017, at 12:08 PM, Charles Thurston <[email protected]> wrote: > > Hello > > Ken nailed it right on the head. I do try not to tie devices all over the > building to the same circuit, BUT could. Like I said what it shows on the > panel can be programmed by the alarm system programmer. If the Local AHJ does > not like what it shows it is a very simple matter to change. > > Wednesday, July 5, 2017, 11:54:48 AM, you wrote: > > > Owen, > > First, per NFPA 72 a tamper switch is defined as a supervisory > signal-initiating device in chapter 17.16 [2013]. It functions when a switch > is closed, completing a circuit. In this respect it is no different than a > smoke detector as the alarm signal, in this case supervisory, is only created > when the valve is moved two or fewer revolutions of the hand wheel of the > valve or upon motion of the control apparatus of the valve of more than 1/5th > of its travel distance. > > As for how many of these devices can be supplied by one pair of wires that > answer is only limited by NFPA 72, which limits the number of such devices on > a circuit. Section 23.8.5.6.2 [2013] advises that: > > The number of supervisory signal–initiating devices permitted to be connected > to a single initiating device circuit shall not exceed 20. > There may be limitations established by the device manufacturer, or the > panel, or the addressable modules and the listing of those devices should be > reviewed prior to raising an alarm [no pun intended]. > > Further, the explanatory text in the handbook gives the following information > [all emphasis is mine]: > > The Code permits up to 20 supervisory signal–initiating devices on a single > initiating device circuit because doing so does not degrade the reliability > or operability of the fire alarm system. Site specific needs and conditions > might dictate that a circuit serves fewer devices. For example, if a facility > has 20 sprinkler control valves each equipped with a supervisory switch, all > the valve supervisory switches could be connected to the same initiating > device circuit and still comply with the Code. However, if a supervisory > signal were received, it would require that someone check every valve to find > the one initiating the signal. Supervisory signal–initiating devices include > valve supervisory switches, air pressure switches, building temperature > switches, fire protection water tank level and temperature switches, and other > devices that are designed to ensure that fire protection and life safety > features are in service at the time of a fire. Refer to the defined terms > supervisory signal-initiating device and supervisory signal in 3.3.132.5 and > 3.3.257.9. > So, there doesn't appear to be any reason that such an arrangement as you've > described would not be in compliance with the applicable code. You might > also ask for testing to prove that the tampers on all of the valves generate > the required signal at the panel. > > sincerely, > Ken Wagoner, SET > Parsley Consulting > 350 West 9th Avenue, Suite 206 > Escondido, California 92025 > Phone 760-745-6181 > Visit our website > On 07/04/2017 9:38 AM, [email protected] wrote: > > Here is the situation on an installation at a new hotel. The DCVA has tamper > switches. Two PIV's near by do not have tamper switches. The hotel is > complete, no wiring had been run to the PIV's. (CFC 903.4) The DCVA and PIV's > sit within the same large planter with lots of finished concrete between the > valves and the alarm panel, about 150'. So the alarm guys tapped into the > wiring of the DCVA tampers and ran it to the PIV's to install tampers. Is > that legal? If a PIV is closed will it show at the panel or monitoring > company as a DCVA tamper? I'm not knowledgeable on the wiring of devices. > Owen Evans > 13D Design > > Sent from my iPhone > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > -- > Best regards, > Charles Thurston [email protected] > MYRTLE BEACH FIRE SAFETY GROUP > A Division of Pye-Barker Fire Safety > 1445 Cannon Road > Myrtle Beach, SC 29577 > (843) 916 - 8787 > (843) 839 - 3473 facsimile > > <int_1.jpg> >> >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > >
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