Electrical Equipment; Plant Specifications; Checking Electrical Equipment; Checking The Alternator - Kohler KD 425-2 Workshop Manual

XII

ELECTRICAL EQUIPMENT

Internal built-in alternator
cables: Color x Section (mm²)
50
External alternator
cables: Color x Section (mm²)
51
52
53
- 30 -
54

Plant specifications

Starter motor: Left rotation, 12V, power from 1.25 to 1.4 kW
Built-in alternator: 280W
Voltage regulator: Electronic with controlled diodes and connection
for battery charge indicator light
External alternator: 12V - 400W
Recommended battery: Refer to tables in chapters 4
Flywheel ring gear: Check teeth for wear or damage. Fit crown whe-
el to flywheel by pre-heating to 200-250°C.
Description (fig. 50-51)
1. Ignition key (optional)
2. Voltage regulator
3. Engine starter
4. Battery (not included)
5. Alternator
6. Pressure switch
7. Battery recharge warning light (optional)
8. Oil pressure warning light (optional)

Checking electrical equipment

1. Make sure that the connections between the voltage regulator
and alternator are correctly made and in good condition.
2. Disconnect the starter motor wire from the battery terminal and
connect a dc ammeter (fig.50 and 51).
3. Connect a dc voltmeter to the battery terminals (fig.50 and 51).
4. Turn over the engine a few times without load or connect an
80÷100W lamp load across the battery to restrict voltage to lower
than 13V.
5. Accelerate the engine to 3000 rpm. The current shown by the
ammeter must be in line with the values indicated in figure 52.
6. Disconnect the load from the battery (if it was previously connec-
ted) and keep the engine running at the above indicated speed
for a few minutes, the battery voltage should slowly increase until
it reaches approximately 14.2V. At the same time the charge cur-
rent should drop to around 2A in a period of time that depends on
the whether the battery is fully charged or not.
7. If the charging current is absent or is lower than the value indica-
ted above, proceed by checking the alternator and if necessary,
renewing the voltage regulator.

Checking the alternator

Check:
1. with motor stopped: the continuity of the windings (fig.53) by con-
necting an ohmmeter and ensuring that resistance is zero, and
the insulation between the windings and ground (fig. 54) by en-
suring that the ohmmeter gives a reading of infinite resistance. If
these readings are not obtained the stator must be renewed.
2. with motor running: use a multitester to check the charge current
between the two yellow wires. Bring the engine up to 3000 rpm -
the multitester should give a reading of 35V.
If the values are more than 10V below this value, the rotor is de-
magnetized and the alternator must be renewed.
Important:
1. The alternator will not deliver current when the yellow wires are
disconnected.
2. The alternator will burn out if the yellow wires are connected to
ground.
3. The voltage regulator may be damaged if the ground connection
or other circuit connections are not made properly.
4. The alternator and the voltage regulator will burn out instantly if
the battery connections are inverted.
KD 425-2 Workshop Manual_cod. ED0053029360_1° ed_ rev. 00
Cables color (fig. 50-51)
M Brown
N Black
A White
V Green
R Red