1-5
2. Rear Starter Switch (RSS)
This switch is active only when the (RCS) switch is in
the REAR position. Depressing this switch energizes the
starter circuit.
b. Gauges and Indicators
1. Oil Pressure Gauge (OP)
The oil pressure gauge is used to monitor the engine oil
pressure. Normal oil pressure is 40-60 psig with engine
running at high speed and at operating temperature.
2. Water Temperature Switch Gauge (WT)
This gauge serves a dual function. It is used to monitor
engine coolant temperature as well as serving as the switch
for the high temperature cut out. Normal engine
operating temperature is 180 to 210
_
F. The switch
function should be set to close at 220-230
_
F.
3. Hour Meter (HM)
The unit Hour Meter will total unit operating hours
and is useful for scheduling maintenance intervals.
4. Preheat Light (PHL)
The preheat light will illuminate to indicate that the
glow plug circuit has been energized. This function is
controlled automatically by the Preheat controller. The
light will go out when the glow plugs have been energized
long enough to reach their required temperature for
starting the engine.
5. A/C Stop Light (ASL)
The AC stop light is activated by the oil pressure cut
out switch. Its purpose is to indicate to the operator that
the unit has stopped.
1.9.3 Driver’s Control Panel
a. Switches
1. Front A/C Switch (FAS)
This switch allows the unit to be turned on or off from
the driver’s panel. It is active only when the (RCS) switch
on the unit panel is in the ‘‘front’’ position.
2. Front Starter Switch (FSS)
This switch is active only when the (RCS) switch is in
the FRONT position. Depressing this switch will energize
the engine starter circuit.
3. Preheat Light (PHL)
(Same as on main panel )
4. A/C Stop Light (ASL)
(Same as on Main Panel)
1.10 ALTERNATOR
The Power Pack is equipped with a 28 volt-140 amp.
alternator . The alternator is connected in parallel with the
air conditioning alternator driven by the main engine.
Both of these alternators are used to independently power
the air conditioning system.
NOTE:
The Power Pack engine controls and starter are
12 volt and receive power from the bus 12 volt
batteries.
CAUTION
Observe proper polarity when installing battery.
Negative battery terminal MUST be grounded.
Reverse polarity will destroy the rectifier diodes
in the alternator. As a precautionary measure,
disconnect positive battery terminal when
charging batteries. Connecting charger in
reverse will destroy the rectifier diodes in the
alternator.
The alternator converts mechanical and magnetic
energy to alternating current (A.C.) and voltage, by the
rotation of an electromagnetic field (rotor) inside a
three-phase stator assembly. The alternating current and
voltage are changed to direct current and voltage, by
passing the A.C. energy through a three-phase, full wave
rectifier system. Six silicon rectifier diodes are used.
1.10.1 Integral Voltage Regulator
The regulator is an electronic transistorized device. No
mechanical contacts or relays are used to perform the
voltage regulation of the alternator system. The electronic
circuitry should never need adjustment and the solid state
active elements used have proved reliable enough to
warrant a sealed unit. The system is temperature
compensated to permit a constant voltage rate at all
conditions.
The regulator is an electronic switching device. It
senses the system voltage level and switches the voltage
applied to the field in order to maintain proper system
voltage.
1.11 Starter Lockout (SLO)
The starter lockout (SLO) is an electronically
controlled relay that opens the starter motor circuit when
a preset engine speed is reached. The signal source for the
control is the A.C. output of the unit alternator.
Frequency directly proportional to engine speed is
monitored electronically within the control. When the
speed or frequency reaches the desired setting or setpoint
the output relay within the control circuit is switched.
Figure 1-7. Alternator Schematic Diagram
