Fan Motor Replacement On Belt Drive Fan Assemblies; Fan Motor Replacements On Direct Drive Fan Assemblies With Nema Motors; Energy Recovery Ventilation; Fan Shaft Bearing Removal - Carrier Aero 39MN MW03-110 Series Installation, Start-Up And Service Instructions Manual

a. Dirt deposits on the motor housing can cause overheat-
ing of the motor.
b. Soiling of the impeller can cause vibration that will
shorten the service life of the fan.
c. Accumulation of dirt on the impeller can lead to severe
vibration and can destroy the fan.
d. Only clean when not in motion.
e. The preferred method of cleaning is dry cleaning, e.g.
using compressed air.
f. Do NOT clean the device using a high-pressure cleaner.
g. Do NOT use acid, alkali or solvent-based cleaning
agents.
h. If liquid was used for cleaning, then completely remove
any cleaning agents used. Operate the fan for 2 hours at
maximum speed so that any liquid that entered can evap-
orate.
4. If fan assembly replacement is required, the new fan has a
default address of 1. If control type is MODBUS / BACnet;
the address must be changed to match the number of the fan
removed (see fan numbering label on the ECM Fan Power
Box). See appropriate fan supplier's Operating Manual:
a. ebm-papst: EC-Control 3.20 manual, Section 3.3.3.
b. Ziehl-Abegg: ZAset manual, Section 5.
Fan Motor Replacement on
Belt Drive Fan Assemblies
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 position 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. 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 positions. Use a
complete new set if required. Do not stretch belts over
sheaves. Review the sections on motor and sheave installa-
tion, sheave alignment, and belt tensioning starting on
page 117.
9. Reconnect motor leads, remove tags, and restore power.
Check fan for proper rotation as described in Start-Up,
Checklist.
Fan Motor Replacements on Direct Drive Fan
Assemblies with NEMA Motors
Fan motor replacement on direct drive fan assemblies with EC
motors is not allowed. A new fan assembly is required.

Energy Recovery Ventilation

FAN SHAFT BEARING REMOVAL

1. Isolate the unit from the system by closing dampers to
prevent "pin wheeling." Tie off the fan wheel to prevent
rotation.
2. Lock open and tag electrical disconnect.
3. Enter through fan section access door or remove panels as
required.
4. Loosen motor base to frame bolts. Adjust motor to release
belt tension and remove belts. Do not stretch belts over
sheaves. Damage to belts can result.
5. Remove bolts on bushing of fan shaft sheave, insert bolts
in jacking hole provided on bushing and slowly jack
bushing from sheave. Remove bushing and sheave.
6. Loosen bearing holddown bolts, block shaft up.
7. Loosen bearing setscrews and locking collar, and remove
holddown bolts.
NOTE: To facilitate easy removal of setscrew fastened wheels,
sheaves, or bearings, remove the setscrew completely. Taking
care not to damage threads, insert a flat ended drift or punch,
tap lightly and carefully return the material displaced on the
shaft by the setscrew to its original place.
8. Remove bearing while observing the following precau-
tions:
a. Make certain fan shaft surface is not rough or scored. If
so, clean up surface with fine emery cloth.
b. Add a few drops of oil after cleanup of shaft end.
It should not be necessary to drive a new bearing onto shaft. If
light tapping is needed, do not tap against outer race. Equip-
ment damage may result.
9. Check fan shaft diameter at bearing mount. If worn by
more than 0.001 in. below nominal, shaft should be re-
placed.
10. Install new bearing, tighten holddown bolts, and then
tighten bearing locking collar or setscrews.
11. Make certain fan wheel does not rub sides of fan housing
after installing new bearings.
12. Recoat fan shaft with a rust inhibitor or grease.
13. Replace sheave and belts. Adjust and align as described in
Installation, Sheaves and V-Belts sections.
14. Replace access panels.
15. Restore electrical power.
Routine maintenance of the energy recovery cassettes includes
inspection and cleaning. On occasion, a part may need to be
completely replaced.
IMPORTANT: This unit contains an energy recovery wheel
heat transfer device. Proper service and maintenance 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 section to
the ERV wheel every 6 months or sooner, as required.
2. Remove and wash ERV wheel (or individual segments, if
so equipped) every 6 months, or every 3 months maxi-
mum for smoky or polluted environments. See instruc-
tions for removal and cleaning details.

CLEANING

Periodic cleaning of the energy recovery wheel will depend on
operating schedule, climate and contaminants 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 of the wheel (sizes 36-104)
or the entire wheel (sizes 25 and 30) will remove oil-based
aerosols that have condensed on energy transfer surfaces.
212
CAUTION