FB-IOM-3.0 8-26-20
Standard PSC Motor Fan
Flow Adjustment
Note: Before starting fan motor, follow
steps 1 and 2.
1. Discharge ductwork should be
connected. The minimum
recommended discharge static
pressure is 0.2" wg. Be sure fan
packing is removed from units with
fan packing!
2. All foreign materials should be
removed from duct system. Filters
should be installed where required.
3. Standard PSC motors are shipped
from factory at full speed setting.
Allow motor to run-in at least 15
minutes before adjusting speed.
During initial run-in, check ductwork
connections for leaks and repair if
necessary. (Do not adjust fan speed
down if ductwork is not connected).
4. Unit is equipped with manual fan
speed control, mounted on the
bottom of the line voltage motor
enclosure or electric heat
enclosure. Turning the control
counterclockwise will reduce the fan
speed; clockwise will increase
speed.
5. Set the unit to full heating
(maximum induction). Adjust and
set remote balancing dampers, if
present. Adjust the speed control to
deliver the required CFM by
measuring air quantity at the room
outlets.
6. Proceed to primary air adjustment
procedure, detailed in control
installation information. Fan should
be re-adjusted with primary air and
ventilation air at maximum setpoint,
to insure that no supply air is
discharged at the induction port.
ECM Motor Fan Flow
Adjustment
Note: Before starting fan motor, follow
steps 1 and 2.
1. Discharge ductwork should be
connected. The minimum
recommended discharge static
pressure is 0.2" wg. Be sure fan
packing is removed from units with
fan packing!
2. All foreign materials should be
removed from duct system. Filters
should be installed where required.
3. PWM Fan Speed Controller
a. ECM motors with manual PWM
controllers are shipped from
factory at design CFM when
provided. Otherwise motors are
shipped at motor full speed
setting.
b. ECM motors shipped with remote
PWM controller require a signal from the
DDC controller to control fan speed.
(See page 4 for operating instructions
for remote pwm.)
c. Allow motor to run-in at least 15
minutes before adjusting speed.
During initial run-in, check
ductwork connections for leaks
and repair if necessary. (Do not
adjust fan speed down if
ductwork is not connected).
4. ECM unit is equipped with either a
manual control or a remote control
PWM fan speed controller, mounted
on the bottom of the line voltage
motor enclosure or electric heat
enclosure.
a. The manual PWM controller has
a screwdriver dial adjust pot and
an LED readout. The LED
display shows the flow index
when the screwdriver adjust is
turned. The flow index is a
number from 0-100 which
correlates to a CFM shown in the
PWM calibration table. Use the
screwdriver adjust to set the
CFM of the unit.
b. Remote PWM controllers require
a signal from the DDC controller
to control fan speed. An increase
in DDC voltage signal from 0-
10Vdc correlates linearly to the
0-100 flow index shown in the
PWM calibration table. A green
lamp continuously flashes to
indicate the flow index value.
Long flashes represent the tens
digit and short flashes represent
the units digit of the flow index.
5. Set the unit to full heating
(maximum induction). Adjust and
set remote balancing dampers, if
present. Adjust the speed control to
deliver the required CFM by
measuring air quantity at the room
outlets.
6. Proceed to primary air adjustment
procedure, detailed in control
installation information. Fan should
be re-adjusted with primary air and
ventilation air at maximum setpoint,
to insure that no supply air is
discharged at the induction port.
Maintenance Procedures:
Fan and Motor
Motor is equipped with permanently
lubricated bearings. Inspect fan and
motor assembly for accumulation of dust
and dirt as required by operating
environment. Clean as necessary.
If fan motor does not run:
a. Free rotation of blower wheel fan
packing removed. Freight or
installation damage.
b. Check for proper unit power
Disconnects should be ON .Check
optional fusing.
c. Check for proper control signal, P/E
switch setting, proper air control 24
Vac at fan contactor, coil energized.
If fan motor runs, excessive noise:
a. Clearance problems on blower. All
components securely attached.
b. Verify integrity of ductwork. Leaks
or loose connections. Rattling
diffusers or balancing dampers.
c. Maximum CFM too high, or
discharge static pressure too low
If fan motor runs, insufficient air flow:
a. Check for ductwork restrictions.
Dirty air filters. Clogged water coils.
b. Re-adjust fan speed control.
c. Discharge static pressure too high.
If repair or replacement is required:
Motor and fan should be removed as an
assembly. Disconnect all power before
servicing. Remove the hex nuts from the
mounting lugs holding the fan assembly
to the discharge panel, and lower the
assembly. For model TFS, lift the
motor / blower assembly to release the
tabs from the discharge panel, then
lower the assembly. Do not allow
assembly to hang from wiring.
If removing motor from blower, first
loosen the set screw holding the blower
wheel to the motor shaft. Remove the
three screws holding motor to the fan
housing, and slide motor and fan
housing apart.
Reverse the procedure for assembly.
Note: Over tightening motor mounting
screws may crush isolation bushings,
causing excessive fan noise.
Optional Water Coil
Cleaning
In most cases, the supply side of the
water coil (optional) can be cleaned by
removing the bottom access door and
cleaning the coil face through the open
space between the motor / blower
assembly and the unit casing.
If more space is desired to clean the
water coil, the motor / blower assembly
may be removed and reinstalled as
described above.
To Next Page
Loading...