Vertiv Liebert DA265 - Replacing a Compressor with Mechanical Failure

9.5.8 Replacing a Compressor with Mechanical Failure
WARNING! Risk of electric shock. Can cause serious injury or death. The Liebert® iCOM™ microprocessor
does not isolate power from the unit, even in the Unit Off mode. Some internal components require and
receive power even during the unit off mode of the Liebert® iCOM™ control. Open all local and remote electric
power disconnect switches and verify with a voltmeter that power is Off before working on any component of
the system.
WARNING! Risk of over pressurization of the refrigeration system. Can cause explosive discharge of high
pressure refrigerant, loss of refrigerant, environmental pollution, equipment damage, injury, or death. This
unit contains fluids and gases under high pressure. Use extreme caution when charging the refrigerant
system. Do not pressurize the system higher than the design pressure marked on the unit's nameplate.
NOTE: Release of refrigerant to the atmosphere is harmful to the environment. Refrigerant must be recycled or
discarded in accordance with federal, state, and local regulations.
1. Front seat service valves to isolate the compressor. Recover refrigerant using an approved recovery procedure
and equipment
2. Remove the failed compressor.
3. Keep the replacement compressor sealed until installation is complete to the point that the system isolation
valves are ready to be engaged. Keep exposure of the POE oil in the compressor to the atmosphere to a
minimum.
4. Install the replacement compressor, replace the gaskets or seals on the service valves, and make all
connections. Replace the unloading solenoid if equipped.
5. Once the compressor is completely installed, keep the isolation valves closed to the system and open to the
compressor. Add dry nitrogen to the compressor and check all connections for leaks. With no leaks confirmed,
evacuate the isolated compressor prior to introducing to the rest of the system.
6. When evacuating the isolated compressor volume, pull a vacuum of 500microns with no decay above
1000microns within 20minutes.
Once evacuation requirements of the compressor are met, open the valves to open the compressor to the
system.
7. Check the compressor and system operation. Make any necessary adjustments for proper equipment
operation.
9.6 Evaporator Coil
The DA250 and DA265 units contain single slab coils. This results in different evaporator (suction) temperatures between
System 1 and System 2. The outer coil (System 1) will operate at a higher evaporator temperature than the inner coil
(System 2) when operating at the same compressor loading.
Vertiv | Liebert® DSE Thermal Management System Installer/User Guide
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