Carrier 19XL specifications Compressor Bearing and Gear Mainten, Inspect the Heat Exchanger Tubes

Inspect Refrigerant Float System Ð Perform inspection every 5 years or when the condenser is opened for service. Transfer the refrigerant into the cooler vessel or into a storage tank. Remove the ¯oat access cover. Clean the chamber and valve assembly thoroughly. Be sure that the valve moves freely. Make sure that all openings are free of obstructions. Examine the cover gasket and replace if nec- essary. See Fig. 37 for views of both ¯oat valve designs. On the linear ¯oat valve design, inspect orientation of the ¯oat slide pin. It must be pointed toward the bubbler tube for proper operation.

Fig. 37 Ð 19XL Float Valve Designs

Inspect Relief Valves and Piping Ð The relief valves on this chiller protect the system against the potentially dan- gerous effects of overpressure. To ensure against damage to the equipment and possible injury to personnel, these devices must be kept in peak operating condition.

As a minimum, the following maintenance is required.

1.At least once a year, disconnect the vent piping at the valve outlet and carefully inspect the valve body and mechanism for any evidence of internal corrosion or rust, dirt, scale, leakage, etc.

2.If corrosion or foreign material is found, do not attempt to repair or recondition. Replace the valve.

3.If the chiller is installed in a corrosive atmosphere or the relief valves are vented into a corrosive atmosphere, make valve inspections at more frequent intervals.

Compressor Bearing and Gear Mainten-

ance Ð The key to good bearing and gear maintenance is proper lubrication. Use the proper grade of oil, maintained at recommended level, temperature, and pressure. Inspect the lubrication system regularly and thoroughly.

To inspect the bearings, a complete compressor teardown is required. Only a trained service technician should remove and examine the bearings. The cover plate on older com- pressor bases was used for factory-test purposes, and is not usable for bearing or gear inspection. The bearings and gears should be examined on a scheduled basis for signs of wear. The frequency of examination is determined by the hours of chiller operation, load conditions during operation, and the condition of the oil and the lubrication system. Excessive bearing wear can sometimes be detected through increased vibration or increased bearing temperature. If either symp- tom appears, contact an experienced and responsible service organization for assistance.

Inspect the Heat Exchanger Tubes

COOLER Ð Inspect and clean the cooler tubes at the end of the ®rst operating season. Because these tubes have internal ridges, a rotary-type tube cleaning system is necessary to fully clean the tubes. Upon inspection, the tube condition will determine the scheduled frequency for cleaning, and will indicate whether water treatment is adequate in the chilled water/brine circuit. Inspect the entering and leaving chilled water temperature sensors for signs of corrosion or scale. Replace the sensor if corroded or remove any scale if found.

CONDENSER Ð Since this water circuit is usually an open- type system, the tubes may be subject to contamination and scale. Clean the condenser tubes with a rotary tube clean- ing system at least once per year, and more often if the water is contaminated. Inspect the entering and leaving condenser water sensors for signs of corrosion or scale. Replace the sensor if corroded or remove any scale if found.

Higher than normal condenser pressures, together with the inability to reach full refrigeration load, usually indicate dirty tubes or air in the chiller. If the refrigeration log indicates a rise above normal condenser pressures, check the condenser refrigerant temperature against the leaving condenser water temperature. If this reading is more than what the design difference is supposed to be, then the condenser tubes may be dirty, or water ¯ow may be incorrect. Because HCFC-22 and HFC134-a are high-pressure refrigerants, air usually does not enter the chiller, rather, the refrigerant leaks out.

During the tube cleaning process, use brushes especially designed to avoid scraping and scratching the tube wall. Con- tact your Carrier representative to obtain these brushes. Do not use wire brushes.

Hard scale may require chemical treatment for its pre- vention or removal. Consult a water treatment specialist for proper treatment.

Water Leaks Ð Water is indicated during chiller opera- tion by the refrigerant moisture indicator (Fig. 2A or 2B) on the refrigerant motor cooling line. Water leaks should be re- paired immediately.

Chiller must be dehydrated after repair of water leaks. See Chiller Dehydration section, page 47.

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