Setting The Dirty Filter Switch - Modine MDB Série Manuel D'installation Et De Maintenance

start-uP Procedure
9. Since the position of the burner profile plates has changed
from the setting at the factory, the air volume delivered
by the unit has changed. Re-check the motor amp draw
(for units equipped with a VFD, the amp draw should be
checked at high speed) to make sure it does not exceed
the motor nameplate rating. If the motor amps are too
high, recheck for proper airflow. Contact Modine Technical
Service for additional guidance.
Figure 23.1 - Burner Profile Plate adjustment
REMOVE
REMOVE
REMOVE
LOOSEN
LOOSEN
REMOVE
REMOVE REMOVE
REMOVE
PLATE MOVEMENT
(UP OR DOWN AS POSITION ALLOWS)
Note: The quantity of screws to be removed/reinstalled varies by
Note: The quantity of screws to be removed/reinstalled varies by
model size. The quantity shown above is for reference only.
model size. The quantity shown above is for reference only.
REMOVE
REMOVE REMOVE
REMOVE
REMOVE
REMOVE
REMOVE
PLATE MOVEMENT
(UP OR DOWN AS POSITION ALLOWS)
.75 MINIMUM
1/2" MINIMUM
TO BURNER
1/2" MINIMUM
TO BURNER
.75 MINIMUM

setting the dirty Filter switch

The dirty filter pressure switch is factory installed in the piping
section. The dirty filter pressure switch monitors the pressure
differential between the two sides of the filters. When the
filters become dirty, the differential pressure increases and
trips the pressure switch which energizes a light on the remote
monitoring panel. The pressure differential switch must be field
set because setting the switch requires the blower to be in
operation and the ductwork to be installed.
Figure 23.2 - dirty Filter Pressure switch
REMOVE
LOOSEN
LOOSEN
setting the dirty Filter switch
REMOVE
The range of the dirty filter pressure switch is adjustable
between 0.17" to 5.0" W.C.
1. Ensure that the unit filters are clean. Clean or replace if
necessary.
2. Connect the leads of a continuity tester to the NO and C
terminals of the dirty filter pressure switch.
3. Set the thermostat so that there is a call for heat. This
should fire the burner and the blower should start.
4. Turn the set screw of the pressure switch clockwise until
it stops. This will set the pressure at 5.0" W.C. and the
continuity tester should be sensing an open circuit.
5. Begin turning the screw counterclockwise until the
continuity tester senses a closed circuit. This determines
the base pressure of the system.
6. Turn the screw clockwise until the continuity tester senses
an open circuit and then one additional full turn (This is
approximately 0.25" W.C.) This will allow for the increase in
static pressure due to dirty filters.
7-500.10
C
NO
23