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Fan Pulley Alignment — Align as follows:
1. Loosen setscrews on pulleys.
2. Align pulleys visually and tighten setscrews on fan pul-
ley to lock it in place.
3. Use the methods shown in Fig. 21 to check proper pulley
alignment.
4. If pulleys are not in correct alignment, loosen the motor
holddown bolts and slide the motor axially until the pul-
leys are aligned.
5. Tighten motor holddown bolts.
Pulley and Drive Adjustment — To obtain desired
fan speed, refer to the fan motor and drive data in
Tables 8A-10D and adjust fan motor pulley as follows:
1. Remove belt from fan motor pulley after loosening mo-
tor from motor base.
2. Loosen setscrew in moveable flange of pulley. Screw move-
able flange toward fixed flange to increase the fan speed
and away from fixed flange to reduce speed. Before tight-
ening setscrew, make certain that setscrew is over nearest
flat surface of pulley hub (Fig. 21).
Increasing fan speed produces a greater load on mo-
tor. Do not exceed rated capacity of motor.
Condensate Drains — Keep condensate drains free of
dirt and foreign matter.
Return-Air Filters — Refer to Replacing Filters sec-
tion, page 39, for filter accessibility and removal. Replace
with clean filters of the sizes listed in Tables 1A-1F.
Chilled Water Coil Freeze Protection — Shut off
water supply to unit. Remove side panel of unit and remove
vent and drain plugs in top and bottom of coil header. Drain
coil and blow out remaining water. Reinstall plugs and side
panel.
Alternative freeze protection methods follow:
• Circulate hot water within the water coil’s supply main or
supplementary space heating.
• Close off supply lines to unit and open a union or field-
supplied drain valve in the return line.
IMPORTANT: Draining from return line will not
completely drain water from coils.
After draining as much water as possible from coils, add
sufficient antifreeze to prevent residual water in the coil
from freezing.
• Add a sufficient quantity of non-corrosive antifreeze to the
entire system to prevent all water within the system from
freezing.
Coil Removal — Remove unit panels and corner posts
as required. Disconnect coil connections and remove fasten-
ing screws. Remove coil through end or side sections of unit.
Cleaning Cooling Coil — Remove return-air filters.
Remove any heavy dirt that may have accumulated on un-
derside of coil. Coil can be cleaned more easily with a stiff
brush, vacuum cleaner, or compressed air when coil is dry.
If coil is wet or if water is to be used for cleaning, guard
against splashing water on electrical components or dam-
aging surrounding area. Clean coil baffles as applicable and
check for tight fit to be sure air does not bypass coil.
Cleaning Insulation — The insulation contains an
immobilized antimicrobial agent that helps prevent the
growth of bacteria and fungi. Clean the inner surface of the
insulation according to the separate maintenance instruc-
tions shipped with the unit.
Fig. 20 — Fan Rotation
Fig. 21 — Fan Pulley Adjustments
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