System Sensor WFD20A Installation Instruction page 2

6. Remove the metal cover with the tamper-proof wrench provided. Move
the actuator lever back and forth to check for binding. If the vane binds,
remove the detector and correct the cause before proceeding.
Be sure the direction-of-flow arrow points in the right direction or else water
flow will go unreported, see Figure 3.
figUre 1. moUnTing Dimensions:
3˝
U-BOLT
NUT
PIPE
SADDLE
U-BOLT
WIDTH: SEE TABLE
figUre 2. moUnTing hoLe LocaTion:
REMOVE BURRS FROM EDGE OF HOLE. CLEAN OUT SCALE
AND FOREIGN MATTER FROM INSIDE WALL OF PIPE.
TabLe 1:
WFD MODEL
20,25
30-2, 40, 50, 60, 80
D770-44-00
CAUTION
3.73˝
MODEL
WFD20A
WFD25A
WFD30-2A
WFD40A
WFD60A
WFD80A
1.70˝
PLASTIC
WRONG
RIGHT
HOLE SIZE TORQUE
1 1 / ˝ 30-35ft-lb.
4
2˝ 55-60 ft.-lb.
pre operaTion TesTing
1. Fill the sprinkler system and check for leaks around the waterflow detec-
tor. If it leaks, first check for the proper torque on the U-bolt nuts. If the
leak persists, drain the system and remove the detector (refer to Mainte-
nance). Check for dirt or foreign objects under the gasket, and make sure
that the pipe surface is not dented. Reinstall the detector and check again
for leaks. Do not proceed until all leaks have been stopped.
2. Connect an ohmmeter or continuity tester across the COM and B-NO
switch terminals. The ohmmeter should indicate an open circuit.
3. Deflect the actuator lever and hold it until the pneumatic delay shaft
WIDTH
releases the switch buttons. The ohmmeter or continuity tester should
show a short circuit after the delay has elapsed. If there is no delay,
4.60˝
check the setting of the delay adjustment dial.
4.60˝
figUre 3. assembLY Diagram:
5.20˝
6.77˝
TAMPER PROOF
9.06˝
10.75˝
DELAY
MECHANISM
(REPLACEMENT
(P/N A3008-00)
MOUNTING PLATE
PIPE PIPE SADDLE
PLASTIC VANE
ROLL PADDLE
VANE
OPPOSITE OF
FLOW ARROW
WHILE INSERTING
SADDLE GASKET
W0151-00
Wiring
1. All models have two SPDT switches. Switch contacts COM and B-NO
are closed when water is flowing and open when it is not. Connect the
switches, as shown in Figure 4, depending on the application.
2. When connected to a listed sprinkler/fire alarm control panel, the initiat-
ing circuit must be nonsilenceable.
3. A ground screw is provided with all waterflow detectors. When ground-
ing is required, clamp wire with screw in hole located between conduit
entrance holes. See Figure 5A.
4. If a second conduit entry is required, remove the knockout plug using a
W0106-00
flat blade screwdriver as shown on Figure 5B. Strike sharply with a ham-
mer to pierce the wall of the knockout plug. Move to an adjacent wall
section and repeat until the plug falls out. Make sure that the waterflow
detector is supported adequately during this operation to avoid injury.
High Voltage. Electrocution Hazard. Do not handle live AC wiring or work on a
device to which AC power is applied. Doing so may result in injury or death.
2
WRENCH
(P/N WFDW)
REFER TO
TABLE 1
U-BOLT
WARNING
COVER
COVER
TAMPER
SWITCH
TERMINAL BLOCK
(REPLACEMENT
P/N A77-01-02)
ELECTRICAL
CONDUIT
ENTRANCE
U-BOLT
NUT
PIPE
W0373-00
I56-2338-004R