Let's have a basic understanding of the generator, including its parts and how it functions.

Generators, also known as generator sets, are a popular form of backup power system. They are widely used, especially in areas where stability and reliability are important.

The principle of operation of a generator is to convert mechanical energy into electrical energy. The main purpose of a generator is to produce backup electricity when there is a power outage, so that government agencies or companies can continue to use electricity to replace the main power system.

The basic principles of operation of a generator are divided into two main types:

    • Direct current (DC) generators, also known as dynamos
    • Alternating current (AC) generators, also known as alternators

The main components that make a generator work are:

    • Engine
    • Alternator
    • Controller

These three components are combined to form a complete generator.

The engine can be a gasoline, diesel, or gas engine. It can be used to power a single-phase or three-phase system. The controller can be either manual or automatic.

Industrial generators are usually alternating current (AC) generators, both single-phase and three-phase. They are powered by diesel engines, which are efficient, durable, and provide continuous power.

The operation of a generator involves several steps, including:

    • Exciter: This step generates the magnetic field that is necessary for the alternator to produce electricity.
    • Rotating rectifier: This step converts the alternating current produced by the alternator into direct current.
    • Main generator: This step produces the alternating current that is used to power equipment.
    • Automatic voltage regulator (A.V.R.): This step controls the voltage output of the generator to ensure that it is stable.

Generators come in a variety of shapes and sizes and can be used for a variety of purposes. They can also be adjusted to output different frequencies of electricity. In practice, generators are essential devices that help businesses and organizations to continue operating even during power outages.


To address common questions raised by customers and technicians, we have compiled a collection of questions and corresponding answers to help you clarify any doubts you may have.

What main parts does a generator set consist of?

Answer :
    The main components of a generator set are:
  • Engine Prime Mover: The heart of the generator set, responsible for converting fuel energy into mechanical energy, which is then transferred to the alternator (Alternator) to convert it into electrical energy.
  • Alternator: Responsible for converting mechanical energy from the engine into electrical energy, applying the principle of rotating magnetic fields cutting through coils. The A.C. Generator or Generator (Alternator) consist of Rotor, Stator, Exciter field, AVR (Automatic voltage Regulator), PMG (permanent Magnet Generator)
  • Voltage Regulator: Responsible for controlling the voltage output from the alternator to a specified level.
  • Control Panel: Displays the operating status and controls the operation of the generator set. Divided into manual and automatic control systems. Can be displayed in both analog and digital formats
  • Cooling and Exhaust System: Responsible for cooling the engine and alternator and removing exhaust fumes from the engine.
  • Lubrication System: Responsible for lubricating various parts of the generator set to reduce wear and tear and extend its lifespan.
    In addition to these main components, the generator set may include additional components such as:
  • Battery: Acts as a backup power source for the voltage regulator.
  • Starting System: Starts the engine.
  • Fire Protection System: Protects the engine from fire.
  • The various components of the generator set work together to ensure that the generator set can generate electrical energy efficiently and safely.

Prime Rating vs. Standby Rating Generators

Answer :
Prime Rating vs. Standby Rating Generators

Prime rating and standby rating generators differ in their ability to deliver electrical power. Prime rating generators can deliver continuous power for long periods without interruption, while standby rating generators can deliver maximum power for short periods only.

    1.Prime Rating Generators Prime rating generators are typically used as the main power source for buildings or facilities such as hospitals, industrial plants, and hotels, which require continuous power supply 24 hours a day, 7 days a week. For this reason, prime rating generators are designed and manufactured to be extra durable and can operate at full capacity continuously without interruption.
    2. Standby Rating Generators Standby rating generators are typically used as backup power sources in emergencies such as power outages or power failures. They may only need to provide power for short periods of time, such as a few hours. For this reason, standby rating generators are designed and manufactured primarily for cost-effectiveness and do not need to be as durable as prime rating generators.

Comparison Table

Feature Prime Rating Standby Rating
Power Delivery Capacity Continuous Maximum for short periods
Application Primary power source Backup power source
Design and Manufacturing Emphasizes durability Emphasizes cost-effectiveness


When choosing a generator, it is important to consider the intended use. If you need a primary power source, choose a prime rating generator. However, if you need a backup power source, choose a standby rating generator.

What is ATS

Answer :
    ATS is an abbreviation for Automatic Transfer Switch . Its duty is to command the generator to work automatically during a power outage or power outage. ATS will check if the main power is out or there is a power outage and will send a signal. Go to the generator (generator) to start. When the generator starts until the frequency and voltage reach normal values, then it will command Transfer to take power from the generator (generator) into the system immediately. This operation can set (set) the time, which will be approximately 8-15 seconds. If it doesn't turn on, it means there may be a problem at some point. You can check later.

    Generally, there are two types of ATS:
    1. Type of circuit breaker which will have an amp size according to the size of the breaker and
    2. Contactor type
    In addition, ATS can be further divided into Open Transition (during the transfer there will be a blinking light) and Closed Transition (during the transfer it takes very little time. until the light barely blinks)

What is Permanent Magnet Generator (PMG)

Answer :
Normally, there are 2 types of Excitation systems in generators, which will be briefly described as follows:
    1. The Self excited type receives excitation power from the generator armature (generator output) by using a small amount of magnetic force. The residue from the previous magnetization (residual magnetism) cuts the coil and stimulates the AC voltage through the full wave bridge rectifier circuit to become DC power. This DC power is then fed back into the main field to Increase the original magnetic power even more. This cycle will continue rapidly until the desired pressure is reached. (So ​​the magnet is a temporary magnet which is obtained by flowing through of electric current)
    2. 2. The Permanent Magnet or PMG type is different from the self excited type in that it receives power for excitation from the pilot excitor instead of from the main armature. This pilot excitor is made of permanent magnets, allowing it to work independently without needing to rely on generator output voltage. Like in the case of Self excited
The advantages of the PMG excitation system are:
    1. Able to withstand harmonic loads better than Self excited type.
    2. Can withstand short circuit current up to 300% for 10 seconds.
    3. Able to generate high effective voltage at first start-up. Able to accept loads of all technician load levels. Especially withstanding the motor starting current well.
    In general, generators are small. The standard from the factory uses the self excited excitation system. But if you want to use the PMG model, you can do it, which is an option from the seller.

Does frequent cycling of a generator with an AVR-controlled engine affect the windings?

Answer :
    Generators that use AVR control should not run the engine rpm lower than 47 Hz because if the engine rpm is lower than 47 Hz continuously for a long time, it will cause the Exciter STATOR, Exciter ROTOR, MAIN FIELD ROTOR coils to burn out, as well as age. The use of the ROTATING DIODE will also be short.

What does the warranty cover for the generator?

Answer :
    Generators normally have a warranty for 1 year after they are installed. commissioning on site, which generators generally need to have the engine condition checked. And change the engine oil and various types of filters every 250 hours according to the engine manual. As for the generator, the voltage will be checked. Electrical current of each phase, frequency and control system of the generator.

Installation of the generator set, To be effective, What parts must be taken into account?

Answer :
Must check in the matter of
    Installation location (Location): Consider the direction of air flowing in and out of the room. Must be away from environments with dust, chemicals, and various impurities. and high humidity
    Room Layout: Normally, there must be at least 1.5- 2 meters of space around the generator for maintenance of the generator, along with space for main wires, oil pipes, air intake pipes, and exhaust pipes.
    Ventilation (Room Ventilation) must have good ventilation. To cool the accumulated heat in the room and the generator. The air flows from the rear to the front. There must be air inlets and air outlets that are appropriate to the size of the generator.
    The installation base (Foundation) must be able to support the weight of the entire generator set. Including the reaction force caused by the vibration of the machine. It should be raised about 10-15 centimeters from the floor. The base should be larger than the base of the machine by at least 200-400 millimeters on each side.
    Exhaust pipe (Exhaust pipe) The exhaust pipe should be short. as far as the conditions of the installation location allow and keep the number of elbow joints to a minimum. In the case of a length longer than 10 meters, the pipe diameter must be increased. It depends on the length and number of elbows used.