York Rooftop Unit Y12BC04C1LABAB

CAUTION: Damage can occur if the bearings are over lubricated. Use grease sparingly.

To go to bypass mode, the bypass VFD installed in this unit must be switched by hand on the front of the bypass enclosure in the fan cabinet of the rooftop unit. It does not automatically go to bypass mode if the drive fails.

The switches on the front of the bypass box control its run mode. For normal running:

If the drive fails, switch the BYPASS/OFF/DRIVE switch to BYPASS. If there is a call for the fan, it will go to full speed. If there are VAV boxes, connect them to the circuit at TB1/6 and they will be driven open in bypass mode.

WARNING: Perform all maintenance operations on the blower motor with power disconnected from the unit. Do not attempt to lubricate bearings with the unit in operation.

Indoor Blower Bearing Lubrication Schedule

Sign off on the blower bearing lubrication

CAUTION: Before making any blower speed changes review the installation for any installation errors, leaks or undesirable systems effects that can result in loss of air flow. Even small changes in blower speed can result in substantial changes in static pressure and BHP.

BHP or AMP draw of the blower motor will increase by the cube ratio of the blower speed. Static pressure will increase by the square ratio of the blower speed.

Tables 24 and 25 are for reference only. All blower speed changes must be made by qualified personnel with strict adherence to the fan laws.

Measured CFM based on Figures 58 and 59

WARNING: Perform all maintenance operations on the blower motor with power disconnected from the unit. Do not attempt to lubricate bearings with the unit in operation.

Power disconnected from the unit?

If desired, every three years remove both pipe plugs at each end shell and clean out any hardened grease or foreign matter.

Both pipe plugs removed and cleaned?

Replace one plug on each end with a clean grease fitting.

One plug on each end replaced with a clean grease fitting?

Using a low pressure grease gun, pump grease (Chevron SRI-2 or equivalent) into the bearing cavity until new grease shows at the open port. Do not over-lubricate.

Grease pumped into the bearing cavity until new grease shows at the open port?

CAUTION: Prior to any of the following maintenance procedures, shut off all power to the unit. Failure to do so could cause personal injury. Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. Verify proper operation after servicing.

MOTORS: Outdoor fan motors are permanently lubricated and require no maintenance. Lubrication, if desired, is to be performed by a qualified service agency. Ventor motors are factory lubricated for an estimated 10-year life.

All wires labeled prior to disconnection?

Proper operation verified after servicing?

Sign off on the maintenance procedure

Check if the system is fully factory charged with R-22.

Verify if the correct charge appears on the unit nameplate.

Check if the 30 ton unit has 3 and the 40 ton unit has 4 independent refrigeration systems.

Check if the TXVs are set to maintain 15°F superheat leaving the evaporator coil.

Check if the superheat on each valve is adjustable.

Check if each system has a moisture/liquid sight glass.

Check if the sight glasses are located on the liquid lines in the condenser section.

Check if a clear flow of liquid indicates the unit is properly charged.

Check if any bubbles indicate the system is undercharged or noncondensables may exist.