Major System Components And Operation Data; Geared Twin Screw Compressor; Pressure Vessels - Carrier 30HXC Installation, Operation And Maintenance Instructions

10 - MAJOR SYSTEM COMPONENTS AND
OPERATION DATA

10.1 - Geared twin screw compressor

30HXC units use 06N geared twin screw compressors.
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Nominal capacities range from 137 to 281 kW (39 to 80
•
tons). Economized or non economized models are used
depending on the 30HXC unit size.
10.1.1 - Oil filter
The 06N screw compressor has an oil filter integral in the
compressor housing. This filter is field replaceable.
10.1.2. - Refrigerant
The 06N screw compressor is specially designed to be used in
R-134 a system only.
10.1.3 - Lubricant
The 06N screw compressor is approved for use with the following
lubricant: Carrier material spec PP 47-32.
10.1.4 - Oil supply solenoid valve
An oil supply solenoid valve is standard on the compressor to
isolate the compressor from oil flow when the compressor is not
operating.
The oil solenoid is field replaceable.
10.1.5 - Suction and economizer screens
To increase the reliability of the compressor, a screen has been
incorporated as a standard feature into suction and economizer
inlets of the compressor.
10.1.6 - Unloading system
The 06NW screw compressor has an unloading system that is
standard on all compressors. This unloading system consists of
two steps of unloading that decrease the compressor capacity by
rerouting partially compressed gas back to suction.

10.2 - Pressure vessels

10.2.1 - Evaporator
30HXC chillers use a flooded evaporator. The water circulates in
the tubes and the refrigerant is on the outside in the shell. One
vessel is used to serve both refrigerant circuits. There is a center
tube sheet which separates the two refrigerant circuits. The tubes
are 3/4" diameter copper with an enhanced surface inside and
out. There is just one water circuit, and depending on the size of
the chiller, there may be two or three water passes.
At the top of the cooler are the two suction pipes, one in each
circuit. Each has a flange welded to it, and the compressor mounts
on the flange.
The evaporator shell has a thermal insulation of 19 mm thick
polyurethane foam and a water drain and purge. With the very low
temperature option this insulation is 38 mm thick.
10.2.2 - Condenser and oil separator
30HXC chiller use a vessel that is a combination condenser and
oil separator. It is mounted below the cooler. Discharge gas leaves
the compressor and flows through an external muffler to the oil
separator, which is the upper portion of the vessel. It enters the
top of the separator where oil is removed, and then flows to the
bottom portion of the vessel, where gas is condensed and
subcooled. One vessel is used to serve both refrigerant circuits.
There is a center tube sheet which separates the two refrigerant
circuits. The tubes are 3/4" or 1" diameter copper with enhanced
surface inside and out. There is just one water circuit with two water
passes.
The condenser shell can have a thermal insulation of 19 mm thick
polyurethane foam and a water drain and purge.
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