Tjernlund LB1 Dryer Duct Booster 8504142 - Manual (Page 2)

INSTALLATION RECOMMENDATIONS
Avoid installing the LB1 within 15 equivalent feet* of the
dryer or within 5 equivalent feet of the dryer vent hood,
(See Diagram C).
*Equivalent feet equals linear feet plus 5 additional feet
for each 90 O elbow and 2.5 feet for each 45 O elbow.
Avoid installing the inlet or outlet of the LB1 within 1 foot of
dryer duct elbows.
Install the LB1 as close to the middle of the dryer duct run as possible.
MOUNTING
NOTE: Do not use screws in the dryer duct installation. The LB1 motor can be mounted in
a horizontal or vertical orientation. Discharge must face up if mounted vertically,
(See Diagram D). Do not install the LB1 in an orientation where the sensing tube
port might fill with condensation, (See Diagram B).
1. Considering dryer duct routing and LB1 location, use the (4) #10 x 1 3/4" wood screws to
secure the mounting bracket to the wood structure using the (4) 3/8" holes in the ½ moon
portion of the bracket. Do not to over tighten the screws.
2. Based on the desired mounting orientation, position the mounting bracket onto 3 of the 4
vibration isolators located on the LB1. Tighten the bracket in place using the (3) provided
1/4” nuts.
3. Insert dryer duct on inlet and outlet of LB1 and secure using reinforced foil duct tape.
See “Initial Setup / Reset of Pressure Response Control (PRC)”, below before plugging in.
SEQUENCE OF OPERATION
The LB1 is controlled by an electronic Pressure Response Control (PRC). The control continuously monitors the pressure in the dryer
duct. When the dryer is activated, dryer exhaust pressurizes the inside of the dryer duct, activating the LB1. When the LB1 and dryer
are operating together, they establish a resulting pressure that is monitored by the PRC. When the dryer shuts off, this pressure
decreases and the PRC shuts off the LB1.
INITIAL SETUP / RESET OF PRESSURE RESPONSE CONTROL (PRC)
Each residential capacity clothing dryer installation is unique due to dryer duct length, vent hood type, location of LB1, dryer make &
model, etc. Because of these varying conditions, the LB1 needs to learn the application it is installed on. As part of the start up routine,
the LB1 will load its program (about 20 seconds) and then run for 15-30 seconds to learn the pressure baseline of the vent system when
power is first supplied or if power is reestablished.
IMPORTANT: For new construction or installations where the dryer is not present, it is necessary for the end user of the dryer to
perform the setup procedure below to program the PRC sensing control before initial use of the dryer.
Once dryer, dryer duct and LB1 are installed and before initial use of the dryer OR if the LB1 cycles erratically, the PRC sensing control
can be set / reset by performing the following procedure:
FOLLOW STEPS BELOW FOR INITIAL SETUP / RESET OF PRC SENSING CONTROL
• Remove all articles from the dryer.
• Clean dryer lint trap and reinstall.
• Verify that dryer door is completely closed.
• Verify that dryer vent system is cool. If need be, cool down the vent system by running dryer for 5 minutes on “Air Dry”.
• Verify that dryer is not operating.
FIGURE 8050015 2/25/08
NO YES NO
15 EQUIVALENT FT. 5 EQUIVALENT FT.
DIAGRAM C
DIAGRAM D
HORIZONTAL
MOUNTING VERTICAL MOUNTING
MUST DISCHARGE
FACING UP
When first supplied electrical power or if power is reestablished, the LB1 will load its program (about 20 seconds) and then
run for 15-30 seconds to learn the pressure baseline of the vent system. To prevent injury or impeller damage, install the LB1
in dryer vent system before supplying power.