Design Features; Compressor Construction; Compressor Cooling; Lubrication - Emerson Copeland 4MTL-05 Series Application Manuallines

to the discharge shut-off valve) the temperature is expected to be 15-20 K lower than inside the
cylinder head. This fact must be taken into account when applying the values in Table 4 below.
Application
Low temp
Medium temp
Compressors in parallel
or multi-compressors
Table 4: Superheat recommendations
Caution! The values shown in Table 4 are maximum temperature values inside the cylinder head.
When using a discharge temperature sensor on the discharge line, the temperature drop has to be
considered for the high DLT cut-out setpoint.
NOTE: An additional internal heat exchanger might be required to ensure the recommended
suction superheat values on the compressor inlet are achieved.
2.5

Design features

2.5.1 Compressor construction

Stream CO compressors have a large discharge chamber to eliminate pulsations. The cylinder
2
heads and the discharge plenum are designed to minimize the heat transfer to suction side.
Each cylinder head has a plugged 1/8" - 27 NPTF tapped hole on the high pressure.
Figure 6: Compressor external view

2.5.2 Compressor cooling

Compressor motor cooling must be ensured in all circumstances.
All Stream CO compressors are suction gas-cooled. With suction gas-cooled compressors, the
2
motor is cooled by refrigerant gas that is led through / over the motor. Depending upon the operating
conditions, the maximum allowed suction gas superheat shall not exceed the values shown in the
envelopes.

2.5.3 Lubrication

For small- and medium-size Stream CO
30), an oil splasher system ensures proper lubrication at constant or variable speed.
For large models (4MTL-35 to 4MTL-50) an oil pump is used:
▪ On compressors delivered with Copeland™ Compressor Electronics (-N), the oil pump integrates
an electronic switch to ensure the oil pressure safety functionality.
▪ Compressors with Copeland™ Protection (-P) are designed to accommodate fittings for an OPS2
or a standard oil pressure switch (OPS2 oil sensor included in the oil pump).
▪ The oil pumps used on these compressors are independent of their rotating direction.
AGL_Stream_ST_4MTL_4MSL_EN_Rev02
Minimum Minimum oil
superheat temperature
required required
20 K / 36 °F 30 °C / 86 °F
10 K / 18 °F 30 °C / 86 °F
10 K / 18 °F 30 °C / 86 °F
compressors (4MSL-03 to 4MSL-15, 4MTL-05 to 4MTL-
2
Maximum
acceptable
discharge
temperature
154.4 °C / 310 °F
154.4 °C / 310 °F
154.4 °C / 310 °F
7