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 <http://www.parsleyconsulting.com/> ***
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]
<mailto:[email protected]>> wrote:
Re: Electric monitoring of control valves 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 <http://www.parsleyconsulting.com/>
On 07/04/2017 9:38 AM, [email protected] <mailto:[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
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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
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