Analysis of the problem that the charging current of diesel generator set is too small

Analysis of the problem that the charging current of diesel generator set is too small

When using a diesel generator set, when the generator set is started to the rated speed, sometimes the generator charging current is too small. Below, we will analyze the causes and countermeasures of this phenomenon.

This type of fault is generally caused by the disconnection of individual silicon diode leads or the poor contact between the brush and the slip ring. The specific reasons are as follows:

1. The belt slips;

2. The regulator voltage is low;

3. The magnetic field line of the diesel generator is grounded or the magnetic field coil is partially grounded and shorted;

4. The diesel diode silicon diode lead wire is disconnected and disconnected, so that the armature coil is disconnected in one phase or two phases;

5. Poor contact between the brush and the slip ring (dirty material on the slip ring, too much wear on the carbon brush, insufficient spring pressure, etc.), the contact resistance is large, and the excitation current is reduced.

The following solutions should be adopted for this phenomenon:

1. Check the contact between the brush and the slip ring of the diesel generator, and no abnormality was found;

2. Using the multimeter DC voltage block to measure the regulator output voltage, it is found that the output voltage is very low;

3. Measure the generator output voltage with the multimeter DC voltage block and find that the output voltage is 5V (the wiring of the regulator and the battery should be disconnected during the measurement), which proves that the fault is on the charging generator;

4. When measuring the diode, it was found that four diodes were burned out. When the diode is replaced, the diesel generator is assembled, and then the diesel generator is started to 1300r/min, the charging current meter on the instrument panel is displayed as 15A, indicating that the diesel generator is charging normally.