What Is a Diesel Generator?

Electricity is critical everywhere, from manufacturing and healthcare to data centres and construction sites. Wherever an outage means serious losses, a diesel generator is an indispensable safeguard.

What is a diesel generator?

A diesel generator is a power system that converts the mechanical energy produced by a diesel-fuelled engine into electrical energy. It serves as a backup power source when the mains fails and as a primary power source where there is no grid at all.

How does it work?

A diesel generator consists mainly of:

• a diesel engine,
• an alternator,
• a control panel,
• fuel, cooling and exhaust systems,
• a battery and starting system.

The engine burns fuel to produce mechanical motion; that motion turns the alternator, which converts it into electrical energy. With an automatic transfer switch (ATS) panel, the generator starts automatically when the mains fails and disconnects when the mains returns.

Standby and prime power

Generator catalogues list two power ratings. Standby power is the maximum power available for a limited time during mains outages. Prime power is the power available for an unlimited number of hours under variable load and is roughly 10% lower than standby power. A generator that will run continuously should be sized on its prime rating.

Advantages

• Reliability: Engine technology proven for decades in heavy-duty conditions.
• Fuel efficiency: Long running times with lower consumption than petrol systems.
• Long service life: Many years of service with regular maintenance.
• Wide power range: From small businesses to large industrial plants; Terex Diesel builds generators from 10 to 4,125 kVA.

Where is it used?

Factories, hospitals, data centres, telecoms infrastructure, construction sites, hotels and shopping centres, public institutions, mining sites, agricultural operations and emergency systems.

How to choose one

• Power required (standby/prime)
• Purpose: backup or continuous?
• Fuel consumption
• Engine and alternator brand
• Service and spare parts support
• Noise level: canopied or open type

You can use our power calculator to estimate your power requirement quickly.

Why maintenance matters

Oil changes, filter checks, battery tests and general inspections catch faults before they grow and make sure the generator runs when you need it. See our scheduled maintenance page for details.