Causes of Cummins generator undervoltage

With the continuous advancement of science and technology, the shortcomings of various equipment have been resolved. For example, traditional Cummins generator sets can only be used in large and medium-duty trucks. This is mainly because of the large size, bulkiness, high noise and vibration of traditional generator sets, which makes its power-increase index lower than that of gasoline engines, which limits the use of Cummins generator sets to a very small range. With the introduction of advanced technology, the traditional Cummins generator set has been greatly improved, the existing shortcomings have also been well resolved, and the continuous advancement of innovative technology has further promoted the application of Cummins generator set.

 [Common Cummins Generator Set Failure Analysis]

1. The control wire is invalid or loose. Solution: Check the control wire for repair or locking.

2. Start motor failure, solution: Replace the start motor.

3. Improper start-up procedures for diesel generators. Solution: Start according to the instructions.

4. Engine start relay failure, the solution: replace the start relay.

5. The start / stop switch of the diesel generator fails. The solution: replace the start / stop switch.

6. Diesel generator starter motor assisted translation failure. Solution: Replace the starter motor assisted translation.

[Common Cummins generator undervoltage phenomenon analysis]

1.Mechanical speed regulation of Cummins generator set

The speed regulation of the generator set is divided into electronic speed regulation and mechanical speed regulation. If it is mechanical speed regulation, then there is an oil pump mechanism on the generator set that controls the amount of oil and the oil circuit. It seems to be called a common rail oil pump. For the amount of fuel, let ’s call it a speed control rod. There is a speed-limiting (high-speed) ejector and a speed-adjusting ejector on both sides of the speed governing rod. When it starts and runs for 20 seconds, it reports a low voltage. If it ca n’t go up all the time, it may be caused by the speed not going up. You can adjust the speed control ejector to try. Whenever the generator set fails, there is usually a major fault. The major fault is solved, and a series of times To solve the problem.

 2. Remanence

If the generator has no residual magnetism, then the voltage system of the generator cannot be established at the beginning. For this problem, we must know how much the voltage of the excitation output of the generator AVR voltage regulator plate is, and then on the excitation output line Connect the corresponding voltage source for magnetization (the voltage type should be corresponding and the polarity should not be reversed).

3. The voltage sampling line is loose

This is well understood. If the voltage sampling line is loose, then the voltage cannot be measured.

4.Pressure plate failure

Due to the influence of changes in environmental factors, the parameters of the AVR pressure regulating plate are no longer applicable and need to be readjusted. Generally speaking, such problems do not occur in non-parallel generator sets, because the parameters of the voltage regulating plate are fixed values. (400V), in general, we ca n’t adjust it, only the unit used for parallel operation may have this problem, because the AVR voltage regulator board is adjusted according to the main bus voltage during parallel operation. In general, the parallel device has a voltage regulating signal sent to the AVR pressure regulating board. In this case, you should check whether the voltage regulating signal is connected correctly, or try to use the electronic controls (parallel device, voltage regulating board, etc.) quickly when turning on Reset the voltage.

 5.Ground fault

If the three-phase ground is connected to the outgoing line, the voltage and current are very low. At this time, you should check whether the ground discharge device (such as the ground knife) is closed or grounded.

6, the varistor or rectifier bridge diode on the generator winding is damaged

     The function of the varistor is: the varistor is turned on to reduce the voltage when an overvoltage fault occurs. If the varistor is broken down or turned on for other reasons, then it can be imagined that the voltage must be very low. There are six rectifier bridges. Diodes and the set DC power supply are used to supply the voltage regulating plate and the excitation device. If the rectifier bridge diode is damaged, the role of the voltage regulating plate and the excitation device will be greatly reduced.