C6.2.7/0302-0903/E 10
With service gauges connected to suction and discharge pressure fittings, turn on the compressor. If the suction
pressure falls below normal levels the system is either low on charge or there is a flow blockage in the system.
Single Phase compressors
If suction pressure does not drop and discharge pressure does not rise to normal levels, either the reversing valve
or the compressor is faulty. Use normal diagnostic procedures to check operation of the reversing valve.
Three Phase Compressor
If suction pressure does not drop and discharge pressure does not rise to normal levels, reverse any two of the
compressor power leads and reapply power to make sure compressor was not wired to run in reverse direction. If
pres-sures still do not move to normal values, the compressor may be faulty. If the compressor is in a circuit
containing a reversing valve, this item may be faulty Reconnect the compressor leads as originally configured and
use normal diagnostic procedures to check operation of the reversing valve. If the reversing valve checks out
satisfactorily, then the compressor current draw should be compared to published compressor performance data
at the compressor operating conditions (pressures and voltages) and significant deviations (more than ±15%)
from published values may indicate a faulty compressor.
22 High Potential Testing
Copeland subjects all scroll compressors to a high voltage test after final assembly.
Since high voltage tests lead to premature ageing of the winding insulation, we do not recommend additional tests of
that nature. They may also be carried out with new machines only.
If it has to be done for any reason disconnect all electronic devices (e.g. motor protection module, fan speed control,
etc.) prior to testing. The test voltage of 1000 V plus twice the nominal voltage is applied for 1 - 4 seconds between
motor winding (each one of the phases) and the compressor shell: The maximum leak current limit is approximately
10 mA. Repeated tests have to be performed at lower voltages.
Caution: Do not carry out high voltage or insulation tests if the compressor housing is under vacuum. Copeland Scroll
compressors are configured with the motor down and the pumping components at the top of the shell. As a result, the
motor can be immersed in refrigerant to a greater extent than hermetic reciprocating compressors when liquid
refrigerant is present in the shell. In this respect, the scroll is more like semi-hermetics (which have horizontal motors
partially submerged in oil and refrigerant). When Copeland Scroll compressors are high potential tested with liquid
refrigerant in the shell they can show higher levels of leakage current than compressors with the motor on top
because of the higher electrical conductivity of liquid refrigerant than refrigerant vapour and oil. However, this
phenomenon can occur with any compressor when the motor is immersed in refrigerant. The levels of current leakage
do not present any safety issue. To lower the current leakage reading the system should be operated for a brief
period of time to redistribute the refrigerant to a more normal configuration and the system high potential tested again.
23 Motor Codes
Code 50 Hz 60Hz Connection
Volt ± 10%/~/Hz Volt ± 10%/~/Hz
TF5 200-220/3/50 200-230/3/60 Y
TFD 380-420/3/50 460/3/60 Y
24 Installation
For single operation, four rubber vibration absorber grommets are supplied with each compressor (see fig. 6). They
dampen the start-up surge of the compressor and prevent sounds and vibrations from being transmitted to the
compressor base during opera-tion to a large extent. The metal sleeve in-side is intended as a guide to hold the
grommet in place. It is not designed as a load-bearing member, and excessive torquing can crush the sleeve. Its inner
diameter is approximately 8.5 mm to fit e.g. an M8 screw. The mounting torque should be 13 ± 1 Nm. It is critically
important that the grommet is not compressed. A clearance space of approximately 2-mm between the bottom of the
washer and the top of the grommet spacer is recommended. For multiple or parallel operation please refer to
guidelines C6.2.5/0901-0702/E.
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