Carrier Transicold X4 7300, Operation & Service Manual

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2.3 CONDENSING SECTION
The condensing section (see Figure 2.1 & Figure 2.2 )
consists of an engine-compressor drive (unidrive
assembly), power train (which drives the fans), AutoF-
resh Air Exchange, condenser fan, condenser, radiator,
heat exchanger, solenoid valves, defrost air switch,
piping, wiring, and associated components.
The unidrive assembly (see
Figure 2.2 ) includes the
engine, compressor, alternator, air cleaner, coolant
system, fuel system, engine oil filter system and engine
sensors.
The power train includes the drive belts, gear box, fan-
shaft and clutch.
2.3.1 Engine
The engine is a four cylinder diesel which gives excel-
lent fuel economy. It drives the compressor directly
through a nylon dive gear and adapter. The adapter
also includes a V-belt sheave which drives the power
train. The engine cooling system consists of the radia-
tor (which is mounted with the condenser coil) and
coolant overflow bottle. The engine is equipped with:
• an engine preheater (EPH), which provides easy
starting characteristics.
• spin-on engine oil filter and a spin − on or suction
side fuel filters for easier filter changes. The fuel
filter may also be equipped with a thermostati-
cally controlled fuel heater.
• an alternator which supplies electrical power for
the control system and for battery charging.
Refer to Section 2.7 for engine data.
2.3.2 Engine Air System
The air cleaner prolongs the life and performance of
the engine by preventing dirt and grit from getting into
the engine and causing excessive wear on all operat-
ing parts. It is the responsibility of the operator to give
the air cleaner equipment regular and constant atten-
tion in accordance with the instructions. An air cleaner
service indicator is connected at the outlet. Its function
is to indicate when the air cleaner filter element
requires replacement. (Refer to
Section 8.5.10 .)
The system may be fitted with an intake air tempera-
ture sensor (IAT) and a manifold absolute pressure
transducer (MAP). These sensors are installed when
Carrier Transicold factory monitoring of the air system
is required.
2.3.3 Engine Controls:
a. Fuel/Speed Actuator (FSA)
The FSA combines the fuel shutoff solenoid and speed
control solenoid into one component. Fuel supply to the
injectors and engine speed is controlled by varying rod
position in accordance with the signal from the control
system. In order to ease the load on the system, speed
transition (high to low and low to high) is ramped up or
down over a 10 second period. The FSA is located on
the front of the injection pump.
b. Engine Speed Sensor (ENSSN)
The ENSSN provides the control system with informa-
tion on the speed at which the engine is running. The
ENSSN is located in the gear case cover above the
engine oil filter.
c. Rack Position Sensor (RPS)
The RPS provides the control system with engine fuel
rack (throttle) position information to be used to control
the engine and refrigeration system. The sensor is
located on the injection pump.
d. Engine Oil Pressure Switch (ENOPS)
The ENOPS is normally open and closes on pressure
rise to signal to the control system the engine has suffi-
cient oil pressure for operation. There is a 15 second
delay after the engine starts to allow the oil pressure to
build up before the control system looks at the input
from this switch. The switch is located in the oil filter
mounting assembly.
e. Engine Coolant Temperature Sensor (ENCT)
The ENCT is a thermistor type sensor that provides the
control system with engine coolant temperature infor-
mation to be displayed, recorded in the DataLink data
recorder and used to control the engine and refrigera-
tion system. The sensor is located on the flywheel end
of the cylinder head near the #4 Injector.