Fantech DBF 4XL - Installation Guidelines; Fan and Switch Mounting; Pressure Sensor Switch Operation

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fantech
DBK100XL
FC Mounting
Clamps (optional)
Alternate Location
Secondary Lint Trap
Fan and Switch Mounting
The DBF4XL is to be mounted a minimum of 5 linear (not equivalent)
feet from the dryer outlet. A secondary lint trap can be used in
applications where excessive dryer lint generation is likely or to
increase the time interval between routine maintenance of the Dryer
Booster Fan. (See illustration on right). A mounting bracket (included)
attached to a rafter or joist should be used to stabilize the fan.
Although not recommended, a vertical rigid duct may support the fan
if the duct is securely stabilized. (Consult local codes prior to
supporting the fan in the duct alone.) It is recommended that duct
work be attached to the inlet and outlet of the fan by means of FC
vibration isolation clamps (optional) to permit periodic inspection of
the blower. Refer to maintenance instructions for inspection
recommendations. All duct connections should be properly sealed to
prevent leakage and loss of fan performance. Flex duct connections
between the dryer duct connection and exhaust duct should be
stretched as smooth as possible.
Pressure Sensor Switch
Operation
The DBF4XL contains a positive pressure sensing switch which
recognizes dryer operation and activates the booster fan from an
independent electrical circuit. This eliminates connections through the
dryer circuit which may void the manufacturers’ warranty as well as
manual systems which require the attention of the operator or costly
current/temperature sensing systems.
Power to the booster fan is connected in series through a normally
open terminal on the switch. A pressure tap is connected to a nipple
on the side of the switch. When the dryer begins operation, positive
pressure in the duct causes the switch diaphragm to expand closing
the circuit to the booster fan. An integral delay-on-break timer in the
switch will cycle the fan on for intervals of 10 minutes. Cycle will
reinitiate after a few seconds as long as the dryer is operating. This
will continue until the dryer has stopped and the timer delay period
has lapsed. Drying cycles, the booster fan, the delay timer and the
pressure switch are not adversely affected by the starting/stopping
intervals.
Installation Guidelines
DBF4XL fans are not explosion proof. Do not use the fans if a potentially explosive situation may exist. DO NOT USE with heated air in excess
140F (60C).
Do not install in an exhaust ductwork where the equivalent duct length is < 25 feet (7.62 meters). The DBF4XL is suitable to overcome an equivalent
duct length of 130 feet (40 meters) of 4 inch diameter galvanized steel duct, and to maintain a air velocity of 1200fpm (6.10 m/s).
Calculating Duct Run
To calculate the length of your planned duct run, measure from the dryer to external venting point in roof or wall. For each bend or elbow add 5-7 feet
to your total duct run calculations. The DBF4XL can be used on runs up to 130 feet.
DBF4XL