York PACKAGED ROOFTOP AIR CONDITIONING UNITS YPAL 061

Check the cleanliness of the filters and replace or clean as required.

Examine the damper and operator linkages to ensure that each is free and operating smoothly.

Oil Level Check: The oil level can only be tested when the compressor is running in stabilized conditions, to ensure that there is no liquid refrigerant in the lower shell of the compressor. When the compressor is running in stabilized conditions, the oil level must be be tween 1/4 and 3/4 in the oil sight glass. Note: at shut down, the oil level can fall to the bot tom limit of the oil sight glass.

Oil Analysis: Use York Type “T” POE oil (clear) for units charged with R-410A refrigerant. The type of refrigerant and amount per system is listed on the unit rating plate. A change in the oil color or odor may be an indication of contaminates in the refrigeration system. If this occurs, an oil sample should be taken and analyzed. If contaminations are present, the system must be cleaned to prevent compressor failure.

This can be accomplished through the installation of oversized suction and liquid line driers. The driers may have to be changed several times to clean up the system depending on the degree of contamination.

Add grease slowly with shaft rotating until a slight bead forms at the seals. If necessary, re-lubricate while bearing is stationary. The fan data plate (attached to the fan scroll) lists the type of grease that must be used for lubricating the bearings. Refer to Table 4-1 for lubricating schedule.

In addition to the checks listed in this section, periodic over all inspections of the unit should be ac com plished to ensure proper equipment operation. Items such as loose hardware, component operation, refrigerant leaks, unusual noises, etc. should be investigated and corrected immediately.

To check sheave alignment, a straight edge or a piece of string can be used. If the sheaves are properly aligned, the string or straight edge will touch at all points, as indicated in Figure. 4-1. Rotating the sheaves will determine if the sheave is wobbly or the drive shaft is bent. Alignment error must be corrected to avoid bearing and belt failure.

New belts should be re-checked after 24 hours of operation. On multiple belt adjustable pul leys, the pitch depth should be checked to insure identical belt travel, power transfer and wear. Adjustable motor bases are provided for belt adjustment.

Motor pulleys and blower shaft pulleys are locked in position with either set screws or split taper lock bushings. All set screws and/or taper lock bolts must be checked for tightness and alignment be fore putting equipment into operation.

The filter/drier should be replaced any time work is performed on the refrigerant circuit. The rooftop unit comes with sealed type (non-replaceable) cores as standard. If the unit is not equipped with the optional valve package (suction, discharge, & liquid line valves), the refrigerant will need to be recovered with a recovery machine to replace the filter/drier.;

Bearings must be re-lubricated periodically to assure long life. Motor bearing should be lubricated yearly, but may need lubrication more frequently, depending on severe operating conditions.

Adjust the belt tension if necessary. Re quired belt tension data is supplied on the fan “skid” data plate, attached to the fan housing. Never use a belt dressing on the belts. If belts slip with the prop er tension, use a good grade of belt cleans er to clean the belts.