Daikin Air Handler OAH055GBAC

WARNING: Before servicing fans, lock out and tag out all power to the unit. Fans or belts can cause severe personal injury or death

WARNING: Do not open the hinged access door and screw-fastenerd access panels while the unit is operating. Moving parts and strong suction forces can cause severe personal injury or death

Replace the variable pitched motor sheave with a properly sized, fixed sheave

Replace the adjustable sheaves with fixed sheaves

Measure the diameter of the V-belt outer surface where it passes around the sheave (pitch diameter)

Calculate fan speed from the motor nameplate rpm

Sign off on the fan drive maintenance

CAUTION: Bearing overheating potential. Can damage the equipment. Do not over lubricate bearings. Use only a high grade mineral grease with a 200°F safe operating temperature.

Motor Bearings: Supply and return fans-Supply and return fan motors should have grease added after every 2000 hours of operation.

Using the following procedure, re-lubricate the bearings while the motor is warm, but not running

NOTE: Direct-Drive Class Il fans that are supplied with TECO motors have double shielded bearings on frame sizes 140T-280T. These bearings are pre-packed with a long life grease and are not regreaseable. Larger frame size TECO motors are regreaseable and follow the same lubrication recommendations as all other motors

NOTE: Specific greasing instructions are located on a tag attached to the motor. If special lubrication instructions are on the motor, they supersede all other instructions

Recommended Lubricants for Fan Motor Bearings

Coil is clean for maximum performance

Coil checked under normal operating conditions

Used a chemical coil cleaner on multiple row coils

Followed the chemical cleaner’s instructions

Fins are not damaged while cleaning

Sign off on the coil maintenance

Warning: This maintenance check requires trained personnel with PPE!

Loosen setscrews B and C in moving parts of sheave and pull out external key E.

Adjust sheave pitch diameter for desired speed, open moving parts by half or full turns from closed position.

Replace external key E and securely tighten setscrews B over key and setscrews C into keyway in fixed half of the sheave.

Put on belts and adjust tension. Do not force belts over grooves.

Make future adjustments by loosening the belt tension and increasing or decreasing the pitch diameter of the sheave by half or full turns as required. Readjust belt tension before starting drive.

To provide the same pitch diameter, adjust both halves of the two-groove sheaves by the same number of turns from closed position.

Verify that all keys are in place and that all se screws are tight before starting drive. Check setscrews and belt tension after 24 hours service.

Sign off on the Pitch Key Sheave Maintenance

Filters removed from inside the unit

Wire clips rotated to release filters

Clean filters fully seated in the frame

Pressure drop for installed filters

Typical filter pressure drop for clean filters at rated air flow

Final pressure drop for front loaded filters

Prefilters removed to check the pressure drop of the final filters