Fan Pulley Alignment Ð Align as follows

Fig. 20 Ð Fan Rotation

Fan Pulley Alignment Ð 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 Ð 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 ¯ange of pulley. Screw move- able ¯ange toward ®xed ¯ange to increase the fan speed and away from ®xed ¯ange to reduce speed. Before tight- ening setscrew, make certain that setscrew is over nearest ¯at 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 Ð Keep condensate drains free of dirt and foreign matter.

Return-Air Filters Ð Refer to Replacing Filters sec- tion, page 39, for ®lter accessibility and removal. Replace with clean ®lters of the sizes listed in Tables 1A-1F.

Chilled Water Coil Freeze Protection Ð 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.

Fig. 21 Ð Fan Pulley Adjustments

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 ®eld- 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 Ð 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 Ð Remove return-air ®lters. 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 ®t to be sure air does not bypass coil.

Cleaning Insulation Ð 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.