Inspection in Charging System


1.No-load test (inspect charging circuit without load)
In the no-load test, whether the generated voltage is maintained at a constant level (regulated voltage) is cheeked even if the alternator speed is changed when the electric load is minimum (10A maximum).
The no-load test is required performing under the condition that the output current is 10A maximum. If the output current exceeds 10A, the result may meet the specified value even if the IC regulator has a problem, and the regulated voltage cannot be inspected correctly.
In the IC regulator type alternator, the specified value of the regulated voltage is between approx. 13.5V and 15.1V (when the engine speed is 2,000 rpm).
The measurement result is outside the specified value, the alternator may have a problem. If the value is higher than the maximum limit, the problem should be in the IC regulator. While, the value is lower than the minimum limit, the problem could be in a component of the alternator except for the IC regulator.

2.Load test (inspect charging circuit with load)
In the load test, when the electric load is applied, whether the alternator can output according to the load is checked by measuring the output current.
The important point in this test is applying heavy load as much as possible.
If electrical load is insufficient even if the alternator is normal, it may not exceed 30A of specified value (when the engine speed is 2,000 rpm).
Therefore, if the output current is 30A maximum, it is necessary to increase electrical load and inspect again. The measurement result is less than the specified value, the alternator can be judged faulty. In this case, the possibility of a malfunction is at the part that has a generating function or rectifying function.
Even when the measurement result exceeds 30A, the maximum rated power is not always output. The maximum rated power can be inspected by measuring the generated current limit where the voltage can be maintained constant, when the engine speed is around 2,000 rpm and the electric load is increased.

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