Under Voltage in Diesel Generator Sets

Many people may not be familiar with diesel generator sets, let alone understand what under voltage is. In simple terms, it refers to insufficient operating pressure in the equipment. As we know, the operation of diesel generator sets relies on specific principles and rules, with pressure being fundamental to driving mechanical components. So, what should we do if a generator set experiences under voltage, and how does it affect the unit? Today, the editor from Dingbo Power Generator Factory will address these questions.

Causes and Solutions for Under Voltage

1.Loose Voltage Sampling Line

If the voltage sampling line is loose, voltage cannot be detected properly.

2.Ground Fault

In the case of a three-phase ground fault, both voltage and current will drop significantly. Check if the ground discharge device is closed or grounded.

3.Loss of Residual Magnetism

Without residual magnetism, the generator’s voltage system cannot establish normally. To resolve this, first determine the excitation output voltage (in volts) of the generator’s AVR voltage regulator, then connect a corresponding voltage source to the excitation output line for magnetization.

4.Diesel Engine Speed Regulation Issues

Diesel engine speed regulation systems are either electronic or mechanical. For mechanical regulation, the diesel engine is equipped with an oil pump mechanism that controls fuel quantity and flow, featuring a speed control rod with a speed-limiting (high-speed) ejector pin and a speed-regulating ejector pin on either side. If the unit reports low voltage 20 seconds after startup and the voltage fails to recover, it indicates the speed cannot reach the required standard, leading to under voltage.

5.Generator Voltage Regulator (AVR) Malfunction

Changes in environmental conditions may render the AVR’s parameters unsuitable, requiring re-adjustment. Non-parallel diesel engines typically have fixed, non-adjustable values, while this issue is more common in parallel-operated units. During parallel operation, the AVR must synchronize with the main bus voltage, and the parallel device usually sends a voltage regulation signal to the AVR. First, check for incorrect wiring of the voltage regulation signal. If under voltage occurs, quickly readjust the voltage using electronic controls (e.g., parallel device, voltage regulator) during startup.

Guangxi Dingbo Power Equipment Manufacturing Co.,Ltd was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. The company has a registered capital of 218.88 million yuan. The company covers an area of 86,000 square meters and a building area of 55,000 square meters. There are more than 660 employees, including 456 professional technicians and 106 senior technicians. It has 46 sales and service outlets nationwide. The main products are diesel engines, generator sets, and diesel generators, providing users with a one-stop service of design, supply, debugging and maintenance at any time. Dingbo has always insisted on using first-class talents, building first-class enterprises, manufacturing first-class products, creating first-class services, and making every effort to build a first-class domestic enterprise. If any question please feel free to visit our website https://www.dieselgeneratortech.com/ or send email to [email protected].