Replace a Failed Compressor
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. Use a filter-drier
when charging the system with recovered refrigerant.
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. Use a flow of dry nitrogen through
the piping during brazing to prevent formation of copper oxide scale inside the piping. Copper
oxide forms when copper is heated in the presence of air. POE oil will dissolve these oxides from
inside the copper pipes and deposit them throughout the system, clogging filter driers and
affecting other system components.
A pure dry nitrogen flow of 1-3 ft3/min (0.5-1.5 l/s) inside the pipe during brazing is sufficient to
displace the air. Control the flow using a suitable metering device.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 500 microns. Break the vacuum each time with clean, dry
nitrogen.
8. Evacuate the system a third time to 500 microns.
9. Charge the system with refrigerant (R-407C) based on requirements of the evaporator,
condensing unit and lines. Refer to the unit nameplate.
10. Apply power and operate the system. Check for proper operation. Refer to Table 11.1 on
page77.
11.3.3 Steam Generating Humidifier-Operation Procedures
Steam generating humidifiers operate efficiently over a wide range of water quality conditions and
automatically adjust to changes in the conductivity of water. The system will automatically drain and refill
to maintain a current set point and alert the operator when the humidifier canister needs to be replaced.
The humidifier RUN/DRAIN switch is located in the humidifier assembly. This switch should be in the RUN
position when the humidifier is in normal operation and in the DRAIN position during service. The
electronic control board for the humidifier is also located in the humidifier assembly. When the unit is
energized, power is available to humidifier. Operation involves the following steps:
1. During start-up, when the humidity control calls for humidification, the fill valve will open,
allowing water to enter the canister. When the water level reaches the electrodes, current flows
and the water will begin to warm. The canister fills until the amperage reaches the set point
and the fill valve closes. As the water warms, its conductivity increases and the current flow, in
turn, rises. If the amperage reaches 115% of the normal operating amperage, the drain valve
opens and flushes some of the water out of the canister. This reduces electrode contact with
the water and lowers the current flow to the amperage set point. Boiling soon commences and
the canister operates normally.
Vertiv | Liebert Mini-Mate2—5 ton User Manual| 81
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