Hanbell RC2-1020AV, Manual

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10
3. Lubricants
The main functions of lubrication oil in screw compressors are lubrication, internal sealing and cooling. At most
conditions, the design of positive pressure differential lubrication system makes RC2-AV series to run without extra oil
pump which is necessary for reciprocating compressors. However, in some special applications, it is still necessary to
install an extra oil pump to screw compressors for safety.
Bearings used in RC2-V series compressors require a small and steady quantity of oil for lubrication. Oil injection into
compression chamber creates oil film for sealing in the compression housing to increase efficiency and also dissipate
some compression heat.
Please pay attention to the oil temperature, which is crucial to compressor bearing life. Viscosity of oil becomes low at
high temperatures. Low viscosity of oil results in poor lubrication and poor heat dissipation in the compressor. Viscosity
should be over 10mm
2
/s at any oil temperature. Oil temperature in sump should be kept above the saturated
condensing temperature to prevent refrigerant migration into lubrication system.
If the compressor operates under critical operating conditions, oil cooler is required – please refer to Hanbell selection
software for the required capacity and oil flow of the oil cooler. High-viscosity oil is recommended for high operating
conditions because high discharge temperatures will make oil less viscous. Oil return could be problems from the
evaporator in refrigeration systems and flooded chillers, etc…, in which it is difficult for oil to be carried back and it may
cause oil loss for compressor. If the system encounters oil return problems, an extra 2
nd
oil separator should be
installed between the compressor discharge port and the condenser.
Every HANBELL RC2-AV compressors is equipped with oil sight glasses. The function of internal oil line sight glass is
to monitor lubricant flow to bearings. While reverse running, it is unable to see the oil flow via sight glass. The normal
oil level in the compressor oil sump should be maintained above the top of the low-level sight glass and in the middle
level of high-level sight glass when compressor is running. It is strongly recommended to install the optional accessory
of oil level switch to prevent compressor failure from oil insufficiency.
3.1 Lubricants table
SPECIFICATION UNITS HBR -B05 HBR -B08 HBR -B09 HBR -B04 HBR –B27
COLOR, ASTM
− − − − −
SPECIFIC GRAVITY 0.945 0.94 0.95 0.95
−
VISCOSITY
40
℃
mm
2
/s (cSt)
64 131 175 215.9 150
100
℃
8.9 14.53 16.5 20.8 17.3
FLASH POINT
℃
266 254 265 271 254
POUR POINT
℃
-43 -36.5 -30 -25 -42
T.A.N mg KOH/g
− − − − −
COPPER STRIP
100 /3hr
℃
− − − −
−
MOISTURE ppm
− − − − −
FLOC POINT
℃
− − − − −
DIELETRIC STRENGTH
2.5mm
kV
− −
46.6
−
−
Note: To use oils not listed in the chart, please consult HANBELL firstly for approval.
3.2 Pre-cautions of oil change
1. Use qualified oil only and do not mix different brands of oil. Choice of oil should match characteristics of the
refrigerant used. Some types of synthetic oil is incompatible with mineral oil. Oil remained in the compressor should be
totally cleaned up in the system before charging different brands of oil. Charge the compressor with oil for the first start
and then change it into new oil again to ensure that there’s no mix at all.
2. When using polyester oil for chiller systems, please make sure not to expose oil to the atmosphere for prevention of
change in its property. Therefore, it is necessary to vacuum the system completely when installing the compressor.
3. In order to ensure no moisture inside the system, it is suggested to clean the system by charging it with dry Nitrogen
and then vacuum it repeatedly as long as possible.
4. It is a must to change oil especially if the motor has burned out because acid debris may still remain inside the
system. Please follow the procedures mentioned above to change oil in the system. Check acidity of oil after 72 hours
of operation and then change it again until acidity of oil becomes normal.
5. Please contact Hanbell local distributors/agents for oil selection.