In large medical facilities, diesel generators help keep life-saving equipment running when the power goes out. They also provide backup for hydro dams, where they supply emergency power to spillway controls.

Modern diesel generators are much quieter than older models and require less maintenance. Still, they can be noisy and must be kept away from people.

Cooling System

The cooling system of a generator is vital to prevent the engine from overheating. It works by releasing a coolant that counteracts the heat created by the engine and gets rid of it outside the generator.

There are two types of cooling systems used in diesel generators: water-cooled and air-cooled. The water-cooled system uses a pump to drag the engine water into the radiator. The water will absorb the heat, raise its temperature, and then flow back into the cylinder head water jacket to reduce the engine’s temperature. The air-cooled system is more effective than the water-cooled system because it directly cools the different parts of the engine. It also has a simpler structure, less maintenance, and is more efficient. It uses axial fans with large power and flow to strengthen the cooling effect, as well as a shroud, a shunt plate, and a cylinder liner baffle to improve the utilization of air flow and ensure uniform cooling.

Exhaust System

Like any other engine, a diesel generators produces exhaust that contains poisonous gasses and must be channeled away from the operator and building. Usually, the system is made up of a series of pipes that connect the generator to an exhaust stack. Ideally, the system is designed to minimize back pressure, so that it does not negatively affect engine performance. This can be accomplished by using a short pipe system and avoiding 90 degree bends. Also, slanting horizontal piping and installing a rain cap are recommended to prevent water from entering the system.

The generator's lubricating (oil) system is critical to ensuring that all its different parts work well together. Like other power equipment, it needs to be maintained on a regular basis. This is typically done by following the maintenance schedule provided by the manufacturer. This will normally include checking the oil regularly, commonly before each start, and changing it after a certain number of hours of use.

Voltage Regulator

The automatic voltage regulator (AVR) of a used gensets controls the power output of a generator set. The equipment ensures that the power output is stable regardless of its load.

It prevents the generator from producing too much voltage, which can damage electrical equipment and cause the batteries to overcharge. It also stops the generator from producing too little voltage, which can lead to problems with electrical equipment and the low state of charge of the battery. The AVR uses an excitation system to generate AC power in the generator’s stator by generating electromagnetic fields via the interaction of primary and secondary coils. The system then converts the AC to DC using power potential transformers and saturable current transformers. The AVR then regulates the voltage by changing the position of the movable coil on an axis in parallel with the fixed coil to increase or decrease the magnetic field. The AVR can also be automated, which makes it easier to use and maintain the genset.