York Rooftop Unit Y12FC04C1LABAB

Disconnect power from the blower motor unit

Ensure the unit is not in operation before lubricating bearings

Pipe Plugs Removal and Cleaning

Remove both pipe plugs at each end shell

Clean out any hardened grease or foreign matter

Grease Fitting Installation and Lubrication

Replace one plug on each end with a clean grease fitting

Pump grease (Chevron SRI-2 or equivalent) into the bearing cavity using a low pressure grease gun until new grease shows at the open port

Is the unit equipped with power exhaust fans or a return air fan?

Belt Tension Adjustment Procedure

Loosen the four bolts holding the motor base to the channels

Adjust the belt by turning nuts 'A' (see detail 'B')

Apply a perpendicular force to one belt at the midpoint of the span using a belt tension checker

Enter the deflection distance obtained (in inches)

Select the fan type and motor horsepower

Label all wires prior to disconnection when servicing controls

Filter Inspection and Replacement

Is the dimensional size of the replacement filter the same as the replaced filter?

Verify proper operation after servicing

Ensure power is disconnected from the unit before maintenance

Do not attempt to lubricate bearings with the unit in operation

Switch the bypass VFD manually on the front of the bypass enclosure in the fan cabinet

Ensure the ON/OFF rotary power switch is in the ON position

Set the BYPASS/OFF/DRIVE switch S1 to the DRIVE position

Set the HAND/STOP/AUTO switch S2 to the AUTO position

Set the TEST/NORMAL switch S3 to the NORMAL position

Review installation for errors, leaks, or undesirable system effects

Is the blower speed change necessary?

Enter the measured CFM based on Figures 58 and 59

Calculate the new pitch diameter (PD) of the motor sheave

Select a new motor sheave based on calculated PD