Magic Aire HCA 04, Installation, Operation And Maintenance Manual

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035-000049-001 Page 20 HCA IOM 1.1 8-28-2017
SERVICE
General
1. Place a suitable walkway to protect floor insula-
tion whenever entering the fan section.
2. Review Safety Considerations at beginning of
these instructions. Good safety habits are im-
portant tools when performing service proce-
dures.
3. To make speed measurements, use a laser-style
tachometer and make sure the access doors are
closed.
Fan Motor Replacement
Shut off motor power and lock out power supply.
Procedure:
1. Disconnect motor power and control wiring har-
ness(es).
2. Loosen fan inlet ring on motor side of the unit.
3. Carefully remove motor mounting bolts where
they attach to the housing. WARNING: Blower
motor/wheel assembly will fall, so be sure to fully
support the assembly before removing the bolts.
4. Remove fan motor and wheel assembly and inlet
ring from the blower housing and unit.
5. Remove the wheel from the fan motor shaft by
loosening the setscrew.
6. Before removing motor mount from motor, mark
the location of the motor mount for reference.
7. Attach new motor to existing or new wheel.
NOTE! Install blower ring BETWEEN motor and
wheel.
8. Attach existing motor mount to new motor, using
mark on old motor as a reference.
9. Install motor/wheel/ring assembly in the fan
housing. Ring is loose. Reinstall ring and motor
mount bolts.
10. Reattach motor harness to motor.
11. Return unit to serviceInstall impeller on new mo-
tor (or new impeller on motor):
Fan System Periodic Maintenance
1. Magic Aire strongly recommends use of a Pre-
ventive Maintenance program to insure that the
unit operates safely and efficiently.
2. Deposits of dust or other debris on the impeller
can cause vibration and premature failure. Fol-
low cleaning instructions in section “Fan
Maintenance & Cleaning”.
Fan Maintenance & Cleaning
1. Regular inspection, and cleaning is neces-
sary to prevent imbalance due to ingress of
dirt.
2. Clean the fan’s flow area - maintenance inter-
val in accordance with the degree of contami-
nation.
Verify vibration free motion .
3. The fan wheel can be cleaned with a moist
cloth.
4. Do not use any aggressive, paint solvent
cleaning agents when cleaning.
5. Never use a high-pressure cleaner or water-
spray for cleaning - particularly when the fan
is running.
WARNING! Wet cleaning under volt-
age may lead to electric shock and
serious injury or death!
Coil Cleaning
DETERGENT — Spray mild detergent solution on
coils with garden-type sprayer. Rinse with fresh
water. Check to ensure condensate line is free.
Excess water from cleaning may flood unit if con-
densate line is plugged.
Winter Shutdown (Chilled Water Coil Only)
ANTIFREEZE METHODS OF COIL PROTEC-
TION
1. Close coil water supply and return valves.
2. Drain coil as follows:
Method I — ‘Break’ flange of coupling at each
header location. Separate flange or coupling
connection to facilitate coil draining.
Method II — Open both valves to auxiliary
drain piping.
3. After coil is drained:
Method I — Connect line with a service valve and
union from upper connection to an antifreeze res-
ervoir. Connect a self-priming reversible pump
between the low header connection and the res-
ervoir.
Method II — Make connection to auxiliary drain
valves.
4. Fill reservoir with any inhibited antifreeze ac-
ceptable to code and underwriter authority.
5. Open service valve and circulate solution for
15 minutes; then check its strength.
6. If solution is too weak, add more antifreeze
until desired strength is reached, then circu-
late solution through coil for 15 minutes or
until concentration is satisfactory.
7. Remove upper line from reservoir to reversi-
ble pump. Drain coil to reservoir and then
close service valve.
8. Break union and remove reservoir and its
lines.
9. Leave coil flanges or coupling open and aux-
iliary drain valves open until spring.
AIR DRYING METHOD OF COIL PROTECTION
(Unit and coil must be level for this method.)
1. Close coil water supply and return main
valves.
DANGER
NEVER enter an enclosed fan cabinet or reach
into a unit while the fan is running.
LOCK OPEN AND TAG the fan motor power dis-
connect switch before working on a fan. Take fus-
es with you and note removal on tag. Electric
shock can cause personal injury or death.
LOCK OPEN AND TAG the electric heat coil pow-
er disconnect switch before working on or near
heaters.
Failure to follow these warnings could lead to per-
sonal injury or death.