Inspect The Control Panel; Inspect Purge; Purge Unit Maintenance; Changing Refrigerant Lubrication Filters - Carrier 19DV Series Installation, Operation And Maintenance Instructions

9.3.2 Inspect the Control Panel

Maintenance consists of general cleaning and tightening of connections. Vacuum the control cabinets to eliminate
dust build-up. If the chiller control malfunctions, refer to the Troubleshooting Guide section for control checks and
adjustments.

9.3.3 Inspect Purge

A purge protects the machine against non-condensable gases.
Make sure below procedures are done when chiller is OFF.
1. First drain the liquid in purge tank using refrigerant pump. In Quick Test menu, open purge drain valve, purge
condenser valve, cooler valve and condenser drain valve. Then run refrigerant pump to drain the refrigerant
liquid. It'll take about 15mins.
2. Close all the valves connect purge and chiller. Enter Quick Test menu, check if all the solenoid valves can
work and if vacuum pump can run.

9.3.4 Purge Unit Maintenance

1. Annually inspect the condenser coil and clean if necessary. Begin to clean the coil from the fan side with use
of high-pressure air or condenser coil cleaner.
2. Inspect all the parts in purge system to see whether there is corrosion, terminal loosen or overheating.
3. Yearlychange the drain filter assembly on the liquid returning line of the purge unit.

9.3.5 Changing Refrigerant Lubrication Filters

Change the refrigerant lubrication filter, motor cooling filter, and bearing filter on an annual basis or when the
chiller is opened for repairs. The filters can be isolated so they can be changed with refrigerant remaining in the
chiller.
Strainers such as 2x refrigerant pump suction strainers, and inductor are to be replaced every 5 years or as
required when the machine is open for service. These filters do not contain desiccant for moisture removal so
changing the filter will not change the moisture indicator status.
Change strainers/filters by closing isolation valves and slowly opening the flare fitting with a wrench and back-up
wrench to relieve pressure.
Moisture Removal Filter:
The filter located on the refrigerant lubrication line to bearing and motor cooling should be replaced once a year or
more often if filter condition indicates a need for more frequent replacement. A moisture indicator sight glass is
located downstream of this filter to indicate the moisture level in refrigerant. If the moisture indicator turns yellow,
locate the water source immediately by performing a thorough leak check and replace the filter.

9.3.6 Purge Carbon Filter

Replace only when the filter is damaged or broken.

9.3.7 Changing refrigerant pump

If changing the refrigerant pump is necessary, please follow below procedures:
1. Disconnect the power supply;
2. Open the terminal box of the refrigerant pump (Item 1, Fig. 57), and disconnect the power cable of the
refrigerant pump;
3. Unbolt the refrigerant pump mounting (Item 2, Fig. 57);
4. Unscrew the refrigerant pump inlet and outlet joints (Item 3, Fig. 57);
5. Install the new refrigerant pump;
6. Replace the O-rings in the joints assembly, and connect the inlet and outlet of the refrigerant pump with
new joints;
7. Connect the refrigerant pump power cable to the terminal box.
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