Daikin Daikin Air Handler CAH021GDDC CAH021GDDC

Adjust motor base forward to release belt tension

Remove the belts for easier adjustment

Loosen, but do not remove both of the locking setscrews A in the outer locking ring by using a hex key or torque wrench with a hex bit

Adjust sheave to desired pitch diameter by turning the outer locking ring, using a spanner wrench or drift inserted into the three holes that are located 120° apart on the ring

Tighten BOTH locking screws A in the outer locking ring before operating the drive. Use a torque wrench and tighten to the value

Replace belts and adjust the motor base to tension the belts properly

Do not loosen any screws other than the two locking screws A in the outer locking ring when adjusting the sheave pitch. Do not operate the drive until the locking screws have been set to the torque specifications

WARNING: Personal Injury Hazard. Power supply can cause electrical shock. Always disconnect all power to unit before servicing

WARNING: UV-C exposure is harmful to the skin and eyes. Looking at an illuminated UV-C bulb can cause permanent blindness. UV-C skin exposure can cause cancer

WARNING: Fluorescent bulbs contain mercury, which can cause personal injury if breathed or ingested. Use appropriate protective gear to clean up broken bulbs

Verify the UV lights are off by using the view window

Disconnect power to the power receptacle before servicing

Verify the power is disconnected

Before opening the access panels, use the viewing window to make sure the UV lights are off

Before handling, allow bulbs to cool for 5 minutes

Grasp body of bulb firmly at each end

Check all moving parts for wear

Check bearing collar, sheave, and wheel hub setscrews, sheave capscrews, and bearing hold-down bolts for tightness

Annually check and snug all electrical connections

Inspect for signs of water damage such as corrosion and repair if necessary

Check ground conductor and connection integrity and correct if needed

Replace front load filter option

Filters removed from inside the unit

Wire clips rotated to release the prefilter and the final filter

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

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

Upon completion of the air balance, 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