York YPAL 060, YPAL 061, YPAL 050, YPAL 051 manual Start-Up, Unit Checks, Crankcase Heaters

FORM 100.50-NOM6 (1207)

SECTION 3 – START-UP

To protect warranty, this equipment must be installed and serviced by an authorized JOHNSON CONTROLS service mechanic or a qualified service person experienced in air handling and condenser unit installation. Installation must comply with all ap- plicable codes, particularly in regard to electrical wiring and other safety elements such as relief valves, HP cut-out settings, design working pres- sures and ventilation requirements consistent with the amount and type of refrigerant charge.

Lethal voltages exist within the Con- trol Panel. Before servicing, open and tag all disconnect switches.

Reference publication Form 100.50- SU1 (507) “Quick Startup Guide” for additional information.

CRANKCASE HEATERS

With power applied to the rooftop unit, the crankcase heater for each compressor will be ON whenever the compressor is not running. The heater is interlocked into the compressor motor contactor and is not controlled by the microprocessor.

The purpose of the crankcase heater is to prevent the migration of refrigerant to the crankcase during shutdown, assuring proper lubrication of the compressor on start-up.

Anytime power is removed from the unit for more than an hour, the crankcase heater should be left on for 24 hours prior to start.

Power must be applied to the rooftop unit 24 hours prior to starting the unit compressors. Failure to observe this requirement can lead to compressor damage and voiding of the compressor warranty.

CHECKING THE SYSTEM PRIOR TO INITIAL START (NO POWER)

Unit Checks

1.Inspect the unit for shipping or installation dam- age.

2.Visually check for refrigerant piping leaks.

3.The compressor oil level should be maintained so that an oil level is visible in the sight glass. The

oil level can only be tested when the compressor is running in stabilized conditions, guaranteeing that there is no liquid refrigerant in the lower shell of the compressor. In this case, the oil must be between 3 1/4 and 3/4 in the sight glass. At shutdown, the oil level can fall to the bottom limit of the oil sight glass.

4.Check the control panel to assure it is free of for- eign material (wires, metal chips, etc.).

5.Visually inspect field wiring (power and control). Wiring MUST meet N.E.C. and local codes.

6.Check tightness of terminal lugs inside the power panel on both sides of the contactors, overloads, fuses, and power connections.

7.Verify fuse sizing in main circuits.

8.Verify field wiring for thermostat (if applicable), optional zone sensor, etc.

9.Verify all applicable pneumatic tubing has been field installed for Duct Static Pressure Transducers (VAV units), optional building pressure transducer for power exhaust option, and outdoor static pres- sure prove.

10.Supply exhaust and return fan isolators spring bolts are removed (refer to Figure 3-1).

11. Verify proper bearing and locking collar torque values on supply and exhaust fans (refer to Main- tenance section of manual).

12. Verify proper drive alignment of supply and ex-

haust fans (refer to Maintenance section of man- ual).

JOHNSON CONTROLS 47