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6.5.1
OEM run-test stands
Operating parameters of factory run-test stands should
be checked to ensure compressors operate within nor-
mal limits on initial start-up. Avoid inlet conditions to
evaporators from being too high or too low (i.e. inlet air/
water temperatures).
6.6
Compressor start
6.6.1
Checking the rotation direction
!
!
NOTICE
Risk of compressor failure!
Operate the compressor only in the intended ro-
tation direction!
Direction rotation test without suction shut-off valve:
• Close the solenoid valve (evaporator)
• Start the compressor for a few seconds only
• Correct rotation direction: Suction pressure drops
• Incorrect rotation direction: The pressure remains
unchanged. If the SE-E1 or SE-G1 is installed, it
switches the compressor off. Change the poles of
the terminals on the common supply line!
6.6.2
Lubrication / oil level monitoring
• Switch the compressor off and check the oil level
after temporary stable operation.
• The oil level must be within the sight glass area
(Check the oil level repeatedly within the first hours
of operation)
!
!
NOTICE
Risk of compressor failure due to liquid slug-
ging!
Before adding larger quantities of oil: check the
oil return!
When starting a new system, it might be necessary to
fill in additional oil, thus compensating for the already
circulating oil (e.g. in the liquid receiver or in oil traps).
Monitoring of the oil level is particularly important on
heat pumps and compressors with variable speed
drives where low refrigerant mass flow rates can impact
the oil return to the compressor.
6.6.3
Vibrations
The whole system, particularly the pipelines and capil-
lary tubes, must be checked for abnormal vibrations.
The pipelines should provide enough flexibility to allow
normal starting and stopping of the compressor without
exerting excessive stress on the tube joints. If required,
take additional safety measures.
!
!
NOTICE
Risk of burst pipes and leakages on the com-
pressor and system components!
Avoid strong vibrations!
6.6.4
Cycling rate
The compressor should not start more than 8 times per
hour. Be sure to adhere to the minimum running time:
Motor power
Minimum running time
ORBIT 6
2 min
ORBIT 8
3 min
!
!
NOTICE
Risk of motor failure!
The specified requirements must be ensured by
the control logic!
6.6.5
Checking the operating data
• Evaporation temperature
• Suction gas temperature
• Condensing temperature
• Discharge gas temperature
• Oil temperature
• Cycling rate
• Current
• Voltage
• Oil level
Prepare data protocol.
6.6.6
Particular notes on safe compressor and
system operation
Analysis show that compressor failures are most often
due to an inadmissible operating mode. This applies
especially to damage resulting from lack of lubrication:
• Function of the expansion valve – observe the manu-
facturer's notes!
– Position the temperature sensor correctly at the
suction gas line and fasten it.
– When using a liquid suction line heat exchanger:
Position the sensor as usual after the evaporator
and not after the heat exchanger.
