Ingersoll-Rand 100-200 HP/75-160 KW - Manual (Page 42)

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COOLING FAN MOTOR
In a standard compressor, the cooling fan motor is wired
at the factory. It is a three-phase motor, protected by a
suitable circuit breaker and overload relay. The fan motor
is energized at the same time the compressor drive
motor is energized. The fan motor overload is wired in
series with the compressor drive motor overload. If an
overload occurs in the fan motor circuit, both the fan
motor and compressor drive motor will stop.
AFTERCOOLER
The discharge air aftercooling system consists of a heat
exchanger (located at the cooling air entrance of the
machine), a condensate separator, and an automatic
drain trap.
By cooling the discharge air, much of the water vapor
naturally contained in the air is condensed and
eliminated from the downstream plant-piping and
equipment.
5.3 COOLANT SYSTEM
Coolant is forced by pressure from the receiver/separator
sump to the inlet port of the coolant cooler and the
bypass port of the thermostatic control valve.
The thermostatic control valve controls the quantity of
coolant necessary to provide a suitable compressor
injection temperature. When the compressor starts cold,
part of the coolant will bypass the cooler. As the system
temperature rises above the valve setting, the coolant will
be directed to the cooler. During periods of operation in
higher ambient temperatures, all the coolant flow will be
directed through the cooler.
The compressor injection minimum temperature is
controlled to preclude the possibility of water vapor
condensing in the receiver. By injecting coolant at a
sufficiently high temperature, temperature of the
discharge air and lubricant mixture will be kept above the
dew point.
The controlled temperature coolant passes through a
filter to the airend under constant pressure.
5.0 SYSTEMS
5.1 GENERAL SYSTEM INFORMATION
The SSR compressor is an electric motor driven, single
stage, screw compressor—complete with accessories
piped, wired and baseplate mounted. It is a totally
self-contained air compressor package.
A standard compressor is composed of the following:
■ Inlet air filtration
■ Compressor and motor assembly
■ Pressurized coolant system with cooler
■ Separation system
■ Capacity control system with stepper motor inlet
■ Motor starting control system
■ Instrumentation
■ Safety provisions
■ Aftercooler
■ Moisture separator and drain trap.
Optional accessories can provide for such things as
automatic starting and stopping, remote starting or
stopping, and sequencer.
The motor, airend, separator tank, and piping are
mounted on independent supports. The supports are
isolated from the base by rubber isolation mounts.
Flexible hoses are utilized on the separator tank coolant
out and air discharge to isolate the motor/airend/tank.
5.2 AIR COOLED COMPRESSORS
DESIGN TEMPERATURES
The standard compressor is designed for operation in an
ambient range of 35°F to 115°F (1.7°C to 46°C). When
conditions other than the design levels described are
encountered, we recommend you contact your nearest
Ingersoll-Rand representative for additional information.
The standard maximum temperature 115°F (46°C) is
applicable up to an elevation of 3300 ft (1000 m) above
sea level. Above this altitude, significant reductions in
ambient temperature are required if a standard drive
motor is to be used.
COOLANT COOLER
The cooler is an integral assembly of core, fan and
fan-motor, all mounted in the end section of the
compressor enclosure. The cooling air flows in through
the left end of the enclosure, through the vertically
mounted cooler core, and discharges upward through the
right end of the enclosure.