AERO® Indoor/Outdoor Small Air Handler 39S: General Maintenance

General:

• Place a suitable walkway to protect floor insulation whenever entering the fan section.

• Review Safety Considerations at beginning of these instructions. Good safety habits are important tools when performing service procedures.

• To make speed measurements, use a strobe-style tachometer or calculate per Step 6 of Start-Up, Check List.

Fan Motor Replacement — see Fig. 92-96 for typical motor wiring diagrams.

• Shut off motor power.

• Disconnect and tag power wires at motor terminals.

• 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.

• Mark belt as to position. Remove and set aside belts.

• Remove motor to motor bracket holddown bolts.

• Remove motor pulley and set aside.

• Remove motor.

• Install new motor. Reassemble by reversing Steps 1-6. Be sure to reinstall multiple belts in their original position. Use a complete new set if required. Do not stretch belts over sheaves. Review the sections on motor and sheave installation, sheave alignment and belt tensioning discussed previously (Fig. 63-65).

• Reconnect motor leads and restore power. Check fan for proper rotation as described in Start-Up, Check List.

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 condensate line is plugged.

ANTIFREEZE METHODS OF COIL PROTECTION

• Close coil water supply and return valves.

• 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

• After coil is drained: Method I: Connect line with a service valve and union from upper nozzle to an antifreeze reservoir. Connect a self-priming reversible pump between the low header connection and the reservoir. Method II: Make connection to auxiliary drain valves.

• Fill reservoir with any inhibited antifreeze acceptable to code and underwriter authority.

• Open service valve and circulate solution for 15 minutes; then check its strength.

• If solution is too weak, add more antifreeze until desired strength is reached, then circulate solution through coil for 15 minutes or until concentration is satisfactory.

• Remove upper line from reservoir to reversible pump. Drain coil to reservoir and then close service valve.

• Break union and remove reservoir and its lines.

• Leave coil flanges or coupling open and auxiliary drain valves open until spring.

AIR DRYING METHOD OF COIL PROTECTION (Unit and coil must be level for this method.)

• Close coil water supply and return main valves.

• Drain coil as described in procedures for Antifreeze Methods of Coil Protection.

• Connect air supply or air blower to inlet header connection and close its drain connection.

• Circulate air and check for air dryness by holding mirror in front of open vent in outlet header drain connection. Mirror will fog if water is still present.

• Allow coil to stand for a few minutes; repeat Step 4 until coil is dry.