Electrical Maintenance
87
Battery Fusing
There is a 40A fuse (FS8) that protects the 2
circuit to the relay and fuse assembly in the
control box.
There is a 60A fuse (FS18) that protects the 2AH
circuit to the base controller, which powers the
2AH circuit to the air heater through fuse F5.
Air Heater
The air heater is mounted on the open end of the
intake manifold. It heats the intake air to help the
engine start in cold weather. The air heater is
energized by the microprocessor during preheat,
just before the engine is started.
The heater is probably defective if the resistance
is more than 0.2 ohms and the current draw is less
than 60 amps, or if the current draw is more than
100 amps.
Check the resistance of the air intake heater with
an ohmmeter between the M6 terminal on the
front of the heater and the screw on the back of
the heater (or the heater case). The resistance
should be 0.14 ± 0.02 ohms.
Check the current draw of the heater with a
clamp-on ammeter at the H1 wire near the M6
terminal on the front of the heater. During preheat
the current draw should be approximately 70
amps.
Unit Wiring
Inspect the unit wiring and the wire harnesses
during scheduled maintenance inspections for
loose, chaffed or broken wires to protect against
unit malfunctions due to open or short circuits.
Wire Harness Routing
Do not change the factory routing of the wire
harnesses inside the unit.
Electric Standby AC
Components for SmartPower
Units
Electrical Contactors
Periodically inspect all contactor points for pitting
or corrosion and repair or replace as necessary.
Test the contact points by checking the voltage
drop across each set of points when the contactor
is energized and the system is operating. If the
voltage drop across a set of points is more than 15
Vac, replace the contact points as a set.
Test the contactor coil by checking the voltage
across the coil. The contactor coil should be
energized by a minimum of 10 Vdc.
Generator Contactor – GC
This contactor is energized while in Diesel
operation, and provides 3 Phase AC for the fans
and the optional battery charger. It is electrically
interlocked with the compressor motor contactor
and TRC in 460 Vac systems.
1.
M6 Terminal
Figure 155: Air Heater
1
AEA693
CAUTION: SmartPower units use high
voltage AC for electric standby operation.
Lethal voltage potentials can exist on
connections in the high voltage box. Take
appropriate precautions and use extreme
care when testing the unit.
