Carrier 19DV Series Installation, Operation And Maintenance Instructions page 17

Supply refrigerant is pulled through a filter drier by the refrigerant pump and is pumped to the bearings through
two protective filters and then returned to the evaporator.
There are two pressure sensors located across the refrigerant pump. During RUN mode a minimum of 82.7 kPa is
required for the refrigerant pump delta difference. An alert will trigger if this value is less than 89.6 kPa while the
machine is in normal operating mode. Consult the Controls Operation and Troubleshooting Manual for details.
1.Compressor
2.Condenser
3.High side float chamber
4.Low side float chamber
5.Cooler
6.Economizer
7. Purge system
8. Vent line
9. Refrigerant lubrication system
10. Eductor
: Purge
: Lube system
: Main refrigerant system
Figure 5 – Refrigerant lubrication Cycle
2.5.5.2 Bearings
The 19DV motor-compressor assembly include two sets of purely refrigerant lubricated bearings. The motor shaft
is supported by a combination set of journal bearing and roller element bearings on each end of compressor.
The refrigerant lubrication pressure difference is defined as the bearing input pressure minus the bearing output
pressure plus the Refrigerant Delta P Offset.
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