Fan Motor Replacement; Energy Recovery Ventilation; Cassette Replacement - Carrier Aero 39MN Series Installation, Start-Up And Service Instructions Manual

section Gas-Fired Furnaces (Duct and Rack Systems) on
page 179.
3. Check the appearance of the burner flame. See Fig. 159
on page 180.
4. For single units, be sure circulating air fan is operating
and verify proper airflow through duct furnace.
5. Return thermostat or heat controller to normal setting.

Fan Motor Replacement

1. Shut off motor power.
2. Disconnect and tag power wires at motor terminals.
3. Loosen motor brace-to-mounting-rail attaching bolts.
Loosen belt tensioning bolts to adjust the motor posi-
tion so V-belts can be removed without stretching over
grooves.
4. Mark belt as to position. Remove and set aside belts.
5. Remove motor to motor bracket holddown bolts.
6. Remove motor pulley and set aside.
7. Remove motor.
NOTE: It may be necessary to remove the end panel to
remove larger motors for some unit sizes.
8. Install new motor. Reassemble by reversing Steps 3-7.
Be sure to reinstall multiple belts in their original posi-
tions. Use a complete new set if required. Do not
stretch belts over sheaves. Review the sections on mo-
tor and sheave installation, sheave alignment, and belt
tensioning starting on page 106.
9. Reconnect motor leads, remove tags, and restore pow-
er. Check fan for proper rotation as described in Start-
Up, Checklist.
Energy Recovery Ventilation —
tenance of the energy recovery cassettes includes inspection
and cleaning. On occasion, a part may need to be complete-
ly replaced.
IMPORTANT: This unit contains an energy recovery
wheel heat transfer device. Proper service and mainte-
nance must be conducted as outlined below, or loss of
heat transfer and overall system performance will occur.
1. Remove and clean or replace filters in adjoining sec-
tion to the ERV wheel every 6 months or sooner, as
required.
2. Remove and wash ERV wheel (or individual seg-
ments, if so equipped) every 6 months, or every 3
months maximum for smoky or polluted environ-
ments. See instructions for removal and cleaning
details.
CLEANING — Periodic cleaning of the energy recovery
wheel will depend on operating schedule, climate and con-
taminants in the indoor air exhausted and the outdoor air
supplied to the building.
The wheel is "self-cleaning" with respect to dry particles
due to its laminar flow characteristics. Smaller particles
pass through; larger particles land on the surface and are
blown clear as the flow direction is reversed. Any material
that builds up on the face of the wheel can be removed with
a brush or vacuum. All sizes can be vacuumed.
Cleaning the removable segments (size 08-30) or the en-
tire wheel (size 03-06) will remove oil-based aerosols that
have condensed on energy transfer surfaces.
To clean removable segments (size 08-30):
1. Access the wheel from the exhaust fan side. This may
be easiest from the adjoining section, depending on the
type of section installed. If it is necessary to access
2. Unlock two segment retainers, one on each side of the
3. Use the tip of a flat screw driver to pop the segment
4. Brush foreign material from the face of the wheel.
5. Soak the segments in the solution until grease and tar
6. Rinse dirty solution from segments and remove excess
7. Replace the segments using the Segment Installation
To clean wheels (size 03-06) use this procedure and refer
to Fig. 162:
1. Remove the ERV section side access panel.
2. Remove the upper and lower wheel center partition
3. Remove the upper and lower (2) wheel retainer angles,
4. Slide wheel cassette out of frame (toward main AHU),
5. Follow Steps 2 through 4 of the cleaning procedure for
Routine main-
6. Reinstall the wheel into the section by reversing Steps

CASSETTE REPLACEMENT

1. Inspect the replacement cassette for freight damage
2. Handle ERV cassettes with care. Lift by the bearing
3. Remove the ERV section side access panel.
4. Refer to Fig. 162. Remove the upper and lower wheel
5. Remove the upper and lower (2) wheel retainer angles,
6. Slide wheel cassette out of frame (toward main AHU),
7. The new ERV section may be mounted in any orienta-
8. To ensure that the beams are not racked, check that the
182
from the side of the wheel section, remove side panel
as shown in Fig. 161.
selected segment opening.
out of the wheel. Repeat for each segment.
Wash the segments (or small wheels) in a 5% solution
of non-acid based coil cleaner (such as Acti-Klean) or
an alkaline detergent and warm water.
deposits are loosened. (NOTE: Some staining of the
desiccant may remain and is not harmful to perfor-
mance.) For better cleaning action, rapidly run a finger
across the segment's surface to separate polymer
strips.
water before reinstalling the segments in the wheel.
and Replacement procedure on page 184.
plates (1). This requires removing screws (a) of the up-
per and lower plate.
being careful wheel does not tip and fall out.
and out the side of the unit (3).
removable segments.
1-5.
upon receipt. Inspect the cassette frame, wheel assem-
bly and segments for damage and verify that the wheel
turns freely by hand (clockwise when viewed from
pulley side). Report any damage immediately to the
freight company.
support beam. Holes are provided on both sides of the
bearing support beams to facilitate rigging (Fig. 163).
center partition plates. This requires removing screws
(a) of the upper and lower plate.
being careful wheel does not tip and fall out.
and out the side of the unit (3).
tion. However, make certain that the frame remains
flat and the bearing beams are not racked as shown in
Fig. 164.
distance between the wheel rim and bearing beam is
the same at each end of the bearing beam, to within
of an inch (dimension A and B in Fig. 164). Bearing
beam racking of as little as 0.040 inches (Dim C in
Fig. 164) will cause the wheel to tilt
Adjusting the diameter seals (Fig. 165) will compen-
sate for up to / in. of racking.
1
4
NOTE: If racking is greater than
rected to ensure that the drive belt will not disengage
from the wheel.
1 /
4
/ in. at the rim.
3
16
1 / in., it must be cor-
4