Fiat Kobelco EX355 Tier2, Technical Manual

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T2-3-24 EX355
ELECTRICAL SYSTEM
MONITOR CIRCUIT
The monitor circuit consists of circuits to operate the
hour meter, coolant temperature gauge, fuel gauge,
engine oil level indicator, engine oil pressure indica-
tor, coolant level indicator, engine overheat indicator,
alternator charging indicator, fuel low level indicator,
air cleaner restriction indicator, hydraulic oil level
indicator and engine pre-heat indicator.
Hour meter operates when alternator is charging and
anti load dump relay is energized.
Monitor gauges receive signal from sensors to indi-
cate fuel level and engine coolant temperature.
The monitor controller contains a logic circuit and
transistors to control ground signals for monitor indi-
cator lights.
Monitor controller receives signals from engine oil
level switch, coolant level switch, hydraulic oil level
switch, engine overheating switch, engine oil pres-
sure switch, fuel low level switch, air filter restriction
switch, Q.O.S. controller and alternator.
Monitor controller provides voltages to transistors if
temperature, pressures or levels are outside normal
limits to illuminate indicator lights.
Engine oil level switch is closed when oil level in the
oil pan is OK.
Coolant level switch is closed when coolant level in
the recovery tank is OK.
Hydraulic oil level switch is closed when level in the
hydraulic oil tank is OK.
Fuel low level switch is open when the fuel level in the
fuel tank is above the reserve
Engine overheat switch is open when coolant tem-
perature is within normal operating range.
Engine oil pressure switch opens above 98 kPa
(14.2 psi) and closes when the oil pressure is below.
Engine air filter restriction switch closes when vacuum
is above approx. 635 mm (25 in.) water , and opens
when vacuum is below.
The pre-heating temperature switch is closed when
engine coolant temperature is lower to 10°C.