Generators are extremely important for a variety of industries in order to provide power to remote and urban construction sites and to provide power in the event of a power outage. To better understand how generators work and the types of generators and supplemental equipment that are available, we’ve put together a glossary of generator parts, systems, and components.

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Generators are packaged units that provide electricity via an engine. The engine and various components turn a fuel source into usable electricity for a large number of applications.



The engine is the workhorse of the generator. Generator engines are typically powered by either diesel or natural gas. The fuel turns the engine, and as the engine turns, various components, including the alternator and battery system, turn that mechanical energy into usable electricity for your equipment. The size of the engine typically dictates how much electricity the generator produces.


Alternator/Generator End

The alternator of the generator is what turns the mechanical energy into electricity. The alternator is connected to the engine’s crankshaft via a belt. As the engine turns, it moves the belt, which turns the rotor shaft. The rotor is essentially a magnet, and the area around the magnet is a conductor, which is called a stator. These components work together to create electricity in the form of an alternating (A/C) current.


Fuel System

The fuel system is a vital component of the generator. Without fuel, the engine will fail to operate. This means that the correct fuel must be placed into the generator, and enough fuel must be inside the generator and on-site in order to keep the generator operating. It is recommended to inspect the fuel system and fuel flow prior to operating the generator to ensure that every part is working as expected and there are no kinks or clogs in the fuel lines that would prevent the natural gas or diesel from reaching the engine.

Popular generator fuels include diesel, natural gas, and propane.


Control Panel

The control panel of the generator is the user interface. It allows the generator operator to monitor the various systems of the generator and adjust them as needed. These controls include the amount of voltage produced by the generator, the electrical current, and the frequency of that current. Monitoring of the system is provided by various gauges and displays, and the generator settings are adjusted through a series of buttons and/or switches.


Battery Charger

Like your vehicle, a generator is first started with the help of a battery. Since this battery must be charged, the generator will also contain a battery charger that charges the battery while the generator is in operation.


Voltage Regulator

The alternator of a generator produces A/C current. This is not the desired current for charging a battery storage system or operating various machinery. Instead, direct current (D/C) is needed. The voltage regulator controls the voltage of the current and changes it from A/C to D/C current.


Main Frame/Skid

The main frame or skid is the housing of the generator that holds on it all parts and components. The main frame or skid can be designed to allow the generator to sit on the ground or a concrete pad or it can be mounted to a trailer for easy transportation of the system. It also helps ensure that the generator is properly grounded or earthed, which is essential for property operation and the safety of the system.


Lubrication System

Since generators contain moving parts, they must have a lubrication system. The lubrication system helps ensure that the moving parts do not create excessive friction and overheat, which would cause the system to lockup.


Diesel Generator Sets

Diesel generator sets are complete generator systems that are designed to be operated with diesel fuel, which is great for remote locations. Diesel generators are reliable, require minimal maintenance, and run efficiently but release harmful gases when burned. Regulations governing emissions have tightened in recent years but advances in technology means diesel can be burned cleaner than previously.


Natural Gas Generator Sets

Natural gas generators are designed to run off natural gas, which is great for worksites and construction sites that are located near natural gas lines as they can simply hook up to existing lines. Natural gas units themselves are cheaper than their diesel counterparts but, depending on existing supply lines, installing gas can significantly increase the cost. As they collect gas from existing pipelines, fuel storage doesn’t pose a problem. Natural gas also burns cleaner than diesel.


Portable Generator Sets

Portable generator sets are mounted onto trailers for easy transportation to and from various sites. These generators range in size from small 8kW units to gensets with a rating of 2,500+kW. Portable generators can run on either natural gas or diesel.


Marine Generator Sets

Marine generator sets are specially built for use around bodies of water that may experience high seas and unpredictable weather patterns. They are designed purposely for use on boats and offshore oil rigs. These generators all meet the strict requirements for marine use.




Diesel Engines

Diesel engines are built for use in diesel generators. The engine itself is similar to, though slightly more simple than, an engine designed for natural gas generators. The main difference is in the ignition system and components. 

In a diesel engine, air is compressed by a piston inside a cylinder, causing the air to heat up (to temperatures  of at least 1,000 degrees Fahrenheit). A mist of diesel is added to the cylinder via a fuel injection system and, as the air inside is so hot, the diesel fuel ignites instantly to help turn the engine’s shaft.


Natural Gas Engines

Natural gas engines use a different and more complex ignition system to diesel engines. Here, fuel and natural gas are injected and compressed together, making the air and gas mixture explosive. Spark plugs then ignite the fuel mix to turn the crankshaft.


Marine Engines

Marine engines power marine generators and typically run on either diesel or gasoline so ignition systems will differ depending on the fuel source. Marine engines are also designed to operate in maritime conditions. For example, parts are coated in corrosion resistant materials to withstand wetter conditions.


Parts and Accessories

Generators consist of a number of separate parts and components and can be used in conjunction with a range of accessories. Some of these include:


Load Banks

Load banks are recommended for diesel and gas generator systems. They are designed to help test various power sources for reliable operation and electrical current prior to attaching the generator to a real load. They can also help diesel generators during the combustion process in order to ensure all of the fuel is burned.


Simplex portable load bank

Trailer-mounted load bank from Simplex.


Transfer Switches

Transfer switches improve the safety of generators. These switches help to ground the generator and supply power to equipment by providing a single plug-in point for the generator. Once the transfer switch is in operation, equipment and buildings can be connected to the transfer switch instead of directly to the generator. Automatic transfer switches allow the generator to kick into action automatically when the main power source fails. When the power comes back on, the generator will shut down by itself.



Radiators help keep your generator operating within its recommended thermal limits in order to prevent overheating.



Trailer-mounting small and large generators makes transporting the generator a simple task and is helpful for mobile projects (e.g. road or subway construction) and operations with multiple power needs.



Enclosures can help keep your generator safe and protected against the elements. Generator enclosures help with weatherproofing and sound reduction. Weatherproof enclosures are completely water-resistant to prevent water damage and hazardous situations that can occur when water infiltrates an electrical system. Sound-proofing enclosures are great for populated areas where generator noise is not desired. 

A walk-in generator enclosure offers more room to maintain and repair the generator inside.

Worldwide Power Products is a market leader in power generation equipment. We carry a large inventory of all the generator parts and accessories you’ve just learned about, as well as a vast collection of inspected and tested new and used generator sets.