12
C6.2.44/0219/E
Braze connections can be converted to Rotalock by means of adaptors. Rotalock shut-off valves
are available for the suction as well as the discharge side. Using either straight or angled adaptors
provides a way to convert a Rotalock into a brazing connection.
Refer to
Table 4
for proper tightening torques:
Torque [Nm]
Rotalock 3/4"
– 16UNF
40-50
Rotalock 1"
– 14UNS
70-80
Rotalock 1 ¼"
– 12UNF
110-135
Rotalock 1 ¾"
– 12 UNF
135-160
Table 4
NOTE: More information about adaptors and shut-off valves can be found in the Emerson
spare parts software at
3.6 Oil separator
During any operating cycle of Copeland Scroll Digital compressors, there is a loaded state during
which the compressor operates at full capacity. The velocity of gas during this loaded state is
sufficient to return oil back to the compressor. Laboratory tests have established that there is no
problem in oil return, even when the length of the interconnecting pipe used is 100 metres and the
vertical elevation is 30 metres. Based on such performance, we do not strictly recommend the use
of an oil separator.
3.7 Accumulators
CAUTION
Inadequate lubrication! Bearing destruction!
Minimise liquid refrigerant
returning to the compressor. Too much refrigerant dilutes the oil. Liquid
refrigerant can wash the oil off the bearings leading to overheating and bearing
failure.
Irrespective of system charge, oil dilution may occur if large amounts of liquid refrigerant
repeatedly flood back to the compressor during:
▪
normal off cycles;
▪
defrost;
▪
varying loads.
In such a case an accumulator must be used to reduce flood-back to a safe level that the
compressor can handle. The use of accumulators is dependent on the application. If an
accumulator has to be used, the oil-return orifice should be from 1 to 1.4 mm in diameter for all
models covered in these guidelines, depending on compressor size and compressor flood-back
results.
The size of the accumulator depends upon the operating range of the system and the amount of
subcooling and subsequent head pressure allowed by the refrigerant control.
3.8 Screens
CAUTION
Screen blocking! Compressor breakdown!
Use screens with at least
0.6 mm openings.
The use of screens finer than 30 x 30 mesh (0.6 mm openings) anywhere in the system should be
avoided with these compressors. Field experience has shown that finer mesh screens used to
protect thermal expansion valves, capillary tubes, or accumulators can become temporarily or
permanently plugged with normal system debris and block the flow of either oil or refrigerant to
the compressor. Such blockage can result in compressor failure.
3.9 Mufflers
External mufflers, normally applied to piston compressors in the past, may not be required for
Copeland Scroll compressors.
