Reliable DDX PrePaK D, Instructions For Installation, Operation Care And Maintenance

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2.
General Description
The Reliable Model DDX 4” (100 mm), 6” (150mm) & 8”
(200mm) PrePaKs are completely self-contained, supervised
preaction systems that can be readily installed within a floor
space of 5.15ft
2
(0.44 m
2
) for the 4” and 6” and 7.5ft
2
(0.70m
2
)
for the 8” (not including door swing). Installation of the PrePaK
(not including exterior devices, i.e., detectors and alarm bells),
requires just three piping connections. These connections are
the water supply, the sprinkler system, and the drain. Reference
locations of these piping connections are shown in Fig.1. Also,
two 120 / 220 VAC electrical supply connections are required.
Note:
The Model DDX PrePak is available with an optional air
compressor and an optional Potter Model PFC-4410-RC Re-
leasing/Control Panel wired for a 120 VAC / 60Hz or 220 VAC /
50 Hz power supply.
Figures 16, 17, and 18 in this Bulletin identify the standard and
optional equipment available in Reliable Model DDX PrePak,
Type D, Preaction Systems.
The Reliable Model DDX PrePaK utilizes an optional Potter
Model PFC-4410-RC Releasing Control Panel. This fully pro-
grammable, microprocessor-based releasing panel is Under-
writers Laboratories, Inc. Listed and is in compliance with NFPA
13 and NFPA 72. Because the PFC-4410-RC is totally zone and
output programmable, the Reliable Model DDX PrePaK can be
utilized in many different preaction applications without having
to rewire any of the factory installed devices. Once the previ-
ously described connections are completed, the 24 VDC detec-
tors, output devices, and relay contacts may be connected to
achieve the desired system implementation.
The Model DDX PrePaK can be used in both single and dou-
ble interlock applications. Reliable Single and Double Interlock
Preaction Systems are designed for water sensitive areas that
require protection from inadvertent water flow into the sprinkler
system piping.
The major benefits of a single/double interlock preaction Sys-
tem, when compared with a wet pipe system, are as follows:
A. A fire alarm sounds prior to the flow of water from a sprin-
kler, which may enable extinguishing the fire by handheld
means before the operation of any sprinkler occurs.
B. An annunciator signals whenever the integrity of piping or
sprinklers is accidentally or intentionally disturbed; howev-
er, no water flow occurs at that time.
C. Detection and notification of a fire condition are provided
by fire detectors, without the delay associated with water
delivery time in the event of a fire. Note that with a wet pipe
system, the fire alarm is delayed until after water has begun
flowing from an operated sprinkler.
In single interlock applications, one fire detector senses the
presence of fire, thereby causing the electrical releasing control
panel to activate notification appliances and energize the sole-
noid releasing valve in the open position. The use of cross-zoned
detectors will require operation of two detectors before the so-
lenoid valve can open (
Note:
Verify that the detection method,
including the use of cross-zoned detection, are permitted by all
applicable codes and standards, as well as the requirements
of all authorities having jurisdiction. Cross-zoned detection may
not be permitted in New York City or by Factory Mutual.) The
solenoid valve, when closed, preserves supply water pressure
in the Model DDX valve’s push-rod chamber. Actuating the sole-
noid valve releases that water pressure which allows the Model
DDX valve to open.
To discharge water from sprinklers on a single interlock system
with cross-zoned detection, two separate electrical detection
systems must activate and a sprinkler must open. During the
early stages of a fire, smoke or heat activates the first detector,
which causes the control panel to produce a local alarm and an
alarm at the fire alarm panel. Electrical relays inside the releasing
control panel can be used to shut down air moving equipment
or activate security doors and other electrical devices when the
panel goes into this first condition. Subsequent activation of a
second, nearby or adjacent detector, on a separate detection
system, will cause the panel to energize the solenoid valve open
and release water into the sprinkler piping. Water flowing into
the sprinkler piping will simultaneously produce water pressure
that cause the transfer of contacts in the alarm pressure switch
mounted in the riser assembly, thereby activating a water flow
alarm device. The flow of water into the sprinkler piping effec-
tively converts the dry system into a wet-pipe sprinkler system.
In the event that the fire subsequently produces sufficient heat to
operate a sprinkler, water will flow from that sprinkler.
To flow water into a double interlock preaction system, two
events must take place: a fire detection device must operate,
and a pressure switch must be operated by the loss of system
pressure (sprinkler operation). These two signals, both an elec-
tric signal from the detection system and an electrical signal
from the pressure (pneumatic) sensor, must coexist at the re-
leasing control panel, which only then will energize the solenoid
releasing valve, causing water flow into the sprinkler system and
out of the open sprinkler(s).
In the event that the system piping is ruptured or a sprinkler
is accidentally opened, the system pressure switch will oper-
ate and an alarm will sound. The Model DDX, Type D Valve as-
sembly, however, will not release water since the solenoid valve
remains closed due to only one input into the releasing control
panel.
When using the Reliable Model DDX PrePaK, in either single
or double interlock applications, the sprinkler system is pressur-
ized (supervised) with air provided by the air compressor and
is monitored by a system pressure switch. Alternatively, super-
visory system pressure may be provided by a nitrogen source.
A Model B Hydraulic Manual Emergency Releasing station is
standard equipment in the Model DDX PrePaK. It consists of an
aluminum nameplate mechanically attached to a ball valve. The
valve handle in its OFF position is guarded against accidental
turning to the ON position (and system discharge) by a nylon
cable tie provided with the PrePaK assembly. The cable tie is
designed to allow, in case of an emergency, forceful turning of
the valve handle to the ON position.