Liebert 8 Tons, 50 & 60Hz user manual Replacement Procedures

System Operation, Testing, and Maintenance

Replacement Procedures

Compressor Replacement: Infrequently a fault in the motor insulation may result in a motor burn- out (if system is properly installed, motor burnout rarely occurs). Primarily this type of failure is due to mechanical or lubrication problems, where the burnout is a secondary consequence.

Early detection can prevent a large percentage of the problems that can cause compressor failures. Periodic maintenance inspections by alert service personnel (i.e., identification of abnormal opera- tion) can be a major factor in reducing maintenance costs. It is easier and more cost-effective to imple- ment the necessary preventative steps that ensure proper system operation; rather than ignore a problem until it results in compressor failure and costly replacement. When troubleshooting a com- pressor problem, check all electrical components for proper operation:

! CAUTION

Avoid touching or contacting the gas and oils with exposed skin. Severe burns will result. Use long rubber gloves in handling contaminated parts.

• Check all fuses and circuit breakers.

• Check pressure switch operation.

• If a compressor failure has occurred, determine whether its cause is an electrical or mechanical problem.

! CAUTION

System contains refrigerant. Recover refrigerant before maintenance

Mechanical Failure: If you have determined that a mechanical failure has occurred, the compressor must be replaced.

Electrical Failure: In the event of an electrical failure and subsequent burnout of the refrigeration com- pressor motor, proper procedures must be followed to thoroughly remove any acids that would cause a future failure. There are two kits that can be used with a complete compressor burnout: Sporlan System Cleaner and Alco Dri-Kleener. Follow the manufacturer's procedure. DAMAGE TO A REPLACEMENT COMPRES-

SOR DUE TO IMPROPER SYSTEM CLEANING CONSTITUTES ABUSE UNDER THE TERMS OF THE WARRANTY, THEREBY VOIDING THE WARRANTY.

Replacement compressors are available from your Liebert supplier and will be shipped to the job site in a reusable crate (as required by the service contractor). If the compressor is under warranty, it must be returned to Liebert in order to receive proper warranty credit. It should be returned in the same container the replacement was shipped in. The possible cause(s) or condition(s) of the damage should be legibly recorded on the provided return tag.

Proper procedures to remove and replace the failed compressor are:

1.Disconnect power

2.Attach suction and discharge gauges to access fittings.

3.Recover refrigerant using standard recovery procedures and equipment.

NOTE

Release of refrigerant to the atmosphere is harmful to the environment and unlawful. Refrigerant must be recycled or discarded in accordance with federal, state, and local regulations.

4.Remove failed compressor.

5.Install replacement compressor and make all connections. Pressurize and leak test the system at approximately 150 psig (1034kPa) pressure.

6.Follow manufacturer's instructions for clean out kits.

7.Evacuate the system twice to 1500 microns, and the third time to 500 microns. Break the vacuum each time with clean, dry refrigerant to 2 psig (13.8 kPa).

8.Charge the system with refrigerant (R-22) based on requirements of the evaporator, condensing unit, and lines. Refer to the installation manual or the unit nameplate.

9.Apply power and operate the system. Check for proper operation. Refer to Table 16 for discharge pressure.

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