Precautions for Use of Drum DC Diesel Generator (Part 2)

Continuing from the previous article, when the diesel generator armature is not short-circuited by the load, the generator will not burn out. This is because the DC diesel generators used on tractors are all shunt type. When the diesel generator works at rated power, most of the current generated by the armature winding is output to the external circuit, and a small part is input to the excitation winding to generate a magnetic field. When the armature terminal and the casing are short-circuited, the current of the diesel generator increases rapidly. At this time, a large voltage drop and a strong armature reaction are generated in the motor, so that the output voltage drops sharply, the excitation current disappears rapidly, and the diesel generator The generator voltage is approaching zero. Therefore, the diesel generator will not be burned out when the armature terminal is shorted to the casing

In use, it is sometimes found that the polarity of the diesel generator changes suddenly (that is, the direction of the current sent out changes). This is because when the output current suddenly increases, the strong armature reaction inside the motor changes the direction of the remanence of the iron core, and this situation must be changed so that the charging circuit can work normally. The method of change is: connect the positive pole of the battery to the casing, and the negative pole touches the magnetic field terminal for 2-3 seconds, that is, the remanence direction of the magnetic pole iron core can be changed. (in positive grounded systems).

Sometimes, when the battery is used as the power supply in the maintenance and the fault of the excitation coil is checked by the spark jumping method, if you do not pay attention to the polarity of the connection, the negative pole of the battery is regarded as the ground pole, which changes the current direction of the excitation coil, thereby making the iron core remanent. Orientation changed. Due to the change of the remanence direction, the voltage polarity of the diesel generator also changes. This should be noted.

The mica sheets between the copper sheets of the general DC diesel generator commutator are lower than the copper sheets. This is because the copper sheet wears faster than the mica sheet, and the mica sheet will be higher than the commutator copper sheet after using for a period of time, so that the carbon brush is suspended. In this way, there will be strong sparks between the commutator and the carbon brushes. In order to avoid this phenomenon, after the commutator is polished, a saw blade is used to cut the mica about 0.8 mm below the copper sheet of the commutator. However, in some DC diesel generators such as ZF-28 and ZF-33, artificial mica is used between the copper sheets of the commutator. The machine does not need to be cut low.

Dingbo Power was founded in 2006 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.