WFDN Vane-type Waterflow Detectors
INSTALLATION AND MAINTENANCE INSTRUCTIONS
IMPORTANT
Please Read Carefully And Save
This instruction manual contains important information about the installation and
operation of waterflow detectors. Purchasers who install waterflow detectors for use
by others must leave this manual or a copy of it with the user.
Read all instructions carefully before beginning. Follow only those instructions that
apply to the model you are installing.
CAUTION
The model WFDN is a vane-type waterflow detector for use in wet-pipe fire sprinkler
systems only. Vane-type waterflow detectors shall not be used as the sole initiating
device in both deluge and preaction systems; waterflow detectors used in these types
of systems may result in an unintended discharge caused by a surge, trapped air or a
short retard time.
WARNING
Installation must be performed by qualified personnel and in accordance with all na-
tional and local codes and ordinances.
Shock hazard: Disconnect power source before servicing. Serious injury or death
could result.
Risk of explosion: Not for use in hazardous locations. Serious injury or death could
result.
PRINCIPLES OF OPERATION
Vane-type waterflow detectors mount to water-filled pipes in fire sprinkler systems.
Waterflow in the pipe deflects a vane, which produces a switched output, usually af-
ter a specified delay. All WFDNs have a pneumatically controlled mechanical delay
mechanism. Delays do NOT accumulate; they reset if the flow of water stops or drops
below minimum triggering flow rate before the entire delay has elapsed.
All switches actuate when the waterflow rate is 10 gallons per minute or greater, but
will not actuate if the flow rate is less than 4 gallons per minute. This Safe Signal
installation manual covers the following waterflow detectors for fire sprinkler/fire
alarm applications.
Model
Pipe Size
(inches)
Pipe
Schedule
Max. Pressure
Rating (psig)
WFD20N
2
7 thru 40
450
WFD25N
2.5
7 thru 40
450
WFD30N
3
7 thru 40
450
WFD40N
4
7 thru 40
450
WFD50N
5
10 thru 40
450
WFD60N
6
10 thru 40
450
WFD80N
8
10 thru 40
450
SPECIFICATIONS
Contact Ratings:
10 A @ 125/250 VAC
; 2.5 A @ 24 VDC
Triggering Threshold Bandwidth (Flow Rate):
4 to 10 gpm
Static Pressure Rating:
See models listed below
Dimensions, Installed:
2.6 in H x 3.5 in W x 6.7 in D
Operating Temperature Range:
32°F to 150°F (0°C to 66°C)
Compatible Pipe:
Steel water pipe, schedule 7 through 40 (See chart below)
Shipping Weight:
3 to 6 lbs (according to size)
Enclosure Rating:
NEMA Type 4, as tested by Underwriters Laboratories, Inc.
U. S. Patent Numbers:
5,213,205
CAUTION
Do NOT use any of the WFDN models on copper pipe. The clamping forces of the
mounting bolts may collapse the pipe sufficiently to prevent the detector from func-
tioning properly.
Do NOT install steel or iron pipe sections in copper piping for mounting a waterflow
detector. Incompatibility between the dissimilar metals causes bimetallic corrosion.
INSTALLATION GUIDELINES
Before installing any waterflow alarm device, be thoroughly familiar with:
NFPA 72: National Fire Alarm Code
NFPA 13: Installation of Sprinkler Systems, Sect. 3.17
NFPA 25: Inspection, Testing and Maintenance of Sprinkler Systems, Sect. 5.3.3.2
Other applicable NFPA standards, local codes, and the requirements of the authority
having jurisdiction
NOTE: Installation methods other than those listed in this installation manual may
prevent the device from reporting the flow of water in the event the associated fire
sprinkler system is activated by a fire. Safe Signal is not responsible for devices that
have been improperly installed, tested, or maintained.
1. Mount the detector where there is adequate clearance for installation and re-
moval and a clear view of it for inspections. See Figure 1 for mounting dimen-
sions.
2. Locate the detector 6 to 7 feet above the floor to protect from accidental
damage.
3. On horizontal runs, position the detector on the top or side of the pipe. Do not
mount it upside down because condensation may collect in the housing and
impair the operation of the detector. For vertical flow applications, mount the
detector on pipe through which water flows upward. Otherwise, the unit may
not operate properly.
4. Mount the detector at least 6 inches from a fitting that changes the direction of
waterflow and no less than 24 inches from a valve or drain.
5. Be sure the direction-of-flow arrows and directional cover match the direction
of flow in the pipe. See Figure 6.
MOUNTING INSTRUCTIONS
1. Drain the pipe.
2. Cut a hole in the pipe at the desired location. Center the hole on the pipe, as
shown in Figure 2, and be sure the hole is perpendicular to the center of the
pipe. Before drilling, use a punch or scribe to mark the drill site to prevent the
bit from slipping. If the hole is off center, the vane will bind against the inside
wall of the pipe. Use a drill or hole saw to cut a hole of the proper diameter. See
Table 1 for hole size.
CAUTION
When drilling the hole with a hole saw, make certain that the center of the cut does
not remain in the pipe.
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