Hanbell RC2-1020AV, Manual

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7.3 Parallel system applications
In the rack or parallel system, it is possible to find unequal-distribution of returned oil from the evaporator that could
cause low oil level in one or more of the compressors. Be sure oil level switch is installed inside each compressors and
oil flow switch is installed in each oil return line to monitor sufficient oil returning to each compressor with normal oil
level. The basic design of the system is shown below in Figure 53, twin compressor parallel system connections. The
accessories installed are the basic and any further applications and protection you would like to use, please contact
HANBELL or local distributor/agent for more information or further confirmation.
Figure 53 Parallel system with two compressors
Item Description Item Description Item Description
1 Filter 6 Flow switch 11 Dryer
2 Compressor 7 Oil filter 12 Secondary cooler
3 Check valve 8 Oil cooler 13 Muffler
4 Sight glass 9 Expansion valve
5 Solenoid valve 10 Oil separator
7.4 Oil pump applications
An additional oil pump is recommended to install to the system when the differential pressure between oil pressure and
suction pressure is less than 4bar (for example: water cooled flooder chiller). If compressor is operating at the
mentioned condition, there would be capacity modulation failure and lack of lubrication and could seriously damage the
compressor. Besides the installation of oil pumps, a high – low pressure differential switch is also recommended to
apply to this kind of system. Please contact Hanbell for more detailed information of oil pump.
Figure 54 Oil pump installation
Item Description Item Description Item Description
1 Oil pump 5 Solenoid valve 9 External oil separator
2 Compressor 6 Flow switch 10 Service valve
3 Check valve 7 Oil filter cartridge
4 Sight glass 8 Oil cooler