2205B0JE-DA-J-N_2014.05.
Screw Compressor J-series
Appendix 1.1 Precautions for Design of the Compressor Package
Appendix1-2
3) Control for compressor stop
The following controls are performed before the compressor is stopped.
•
The capacity control slide valve of the compressor is set to the minimum position before it
is stopped.
(Alternatively, the compressor is stopped with the capacity control slide valve is in the low
load position and the capacity control slide valve is set to the 0% position after it is
stopped.)
Motor
The 170J/220J-series is intended for a flange motor in standard.
It is applied for the following standards and frames.
170J
220J
•
NEMA 44*D,
55*D
•
IEC
FF-500,
FF-600
•
NEMA 44*D,
50*D
•
IEC
FF-600,
FF-740
Oil
Separator
The oil separator is required to separate and hold compressor lubricant oil, therefore take the following
points into consideration during design.
1) Oil separation performance
Design the oil separator so that the quantity of oil carried away from the oil separator is below
10 ppm. Consider the gravitational sedimentation method and the types of filter to use.
2) Amount of lubricant held
The amount of lubricant held in the oil separator must at least be more than 1.5 times the
supply lubricant flow rate per minute.
3) Attachment of oil level gauge
To manage the lubricant level, an oil level gauges that shows both the upper and lower level
limit must be provided.
4) Installation of oil heater
An oil heater must be installed at the bottom of the oil separator with appropriate temperature
settings to prevent excessive viscosity increase of lubricant, condensation of refrigerant, and
refrigerant dissolving in lubricant at start up.
If the package is for use in cold regions or the lubricant dissolves excessively in the refrigerant,
the oil separator must be thermally insulated.
5) Sufficient stiffness
If a horizontal type of oil separator with the compressor and motor mounted on top is adopted,
the oil separator must be sufficiently rigidly designed.
The oil separator must have sufficient rigid structure so that no misalignment
trouble occurs to the compressor and motor during operation due to the oil
separator heat stress or deformation due to pressure.
