Diesel Generators: A complete guide to buying the right one.

Diesel Generators: A complete guide to buying the right one.
  • Post category:Diesel generatos
  • Reading time:6 mins read

Diesel generators are being used on construction sites, on events and also as back-up power sources during the load-shedding times for South African homes and businesses.

Diesel generators are a reliable electrical power source, which can be a great investment when well matched with your needs and budget.

Buying a generator is a process that needs to be approached with caution as there is no ‘one size fits all’ option. There are different types of generators, in varying sizes, suited for varied uses. As Waygen Generators, we supply a wide range of diesel generators, from 15kVA to 1500+ kVA custom made gensets to suit your specific needs and budget.

We created this guide so it can assist you in selecting the right generator best suited for your needs.

200kVa Diesel Generator

What is a Diesel Generator?

A diesel generator is machinery that converts the chemical energy in diesel to electrical energy. It does this using a diesel engine and an AC alternator coupled together.

This type of generator can be used for either prime or standby power.

Diesel Generator Engine

Types of Diesel Generators

Prime Power Generators serve as the primary source of electrical power for a given application and typically have an output ranging between 25 kilowatts and 1 Megawatt. they can run 24/7 at variable and maximum loads to completely replace the utility provider, if necessary.

Standby Power Generators serve as backup electrical power source to act as emergency power for when the Grid(mains) fails, suffers a power outage.

Single Phase Generator is an alternating electricity generator that produces a single, continuously alternates voltage. It is mostly used in homes.

Three Phase Generator produces three separate waves of power, delivered in sequence. This ensures a continuous uninterrupted flow of power that never drops to zero. They are more powerful than Single-Phase Generators, usually used in industrial set ups.

Residential Generators offer a limited amount of power, they are perfect for usage in homes, small businesses and offices.

Industrial Generators are typically enormous and can generate a lot of electrical power for a long time. they are commonly employed in industries with high power consumption.

Buying a generator is an important financial and environmental decision.’

Specifications of a Diesel Generator to consider before buying one.


When deciding on the Generator to purchase, it is important to consider the electrical power needs of your home or business. A Diesel Generator that operates under the conditions for which it was designed, has a higher efficiency and longer service life.

Let us look at some of the electrical power units that are commonly used in the Generator industry; kW, kVA, PF.

  • Kilowatts (kW) are used to measure the real electric power provided by the generator, which is used directly by appliances and equipment in the building.
  • Kilovolt-amperes (kVA) measure apparent power provided by the generator. This includes real power (kW) and reactive power (kVAR) drawn by devices like motors and transformers. *Reactive power is not consumed and instead it cycles between the power source and the load.
  • Power factor is the ratio between real and apparent power. If a building consumes 800kW and 1000kVA, the Power Factor is 0.8 or 80%.

Diesel generators have nameplates that have the rated values for kW, kVA and PF. It is important to make sure that the load on the generator does not exceed either the kW rating or the kVA rating, as this can damage the genset. However, going below the rated PF is not recommended, since the generator operates less efficiently.


Diesel generators are available for both single phase and three phase connections.

A single-phase generator is one that is powered by a single alternating current.

A three-phase generator is one that is powered by three conductors. Their set-up relies on three conductors and a fourth neutral wire.

If you are going to be using the generator for back-up, find out if your home/enterprise has a single phase or three phase connection and choose a suitable generator accordingly.

Fuel Consumption

Before buying a generator, get an idea of its possible fuel consumption. Getting a fuel efficient generator will save you a lot of time and also keep operating costs low.

Determine the generator’s fuel consumption per hour and per kVA, as well as the fuel efficiency it delivers with the load before purchasing.

Control and Power Management Systems

For Diesel Generators with the ability to automatically transfer power from the Grid to the generator during a power cut and vice versa, enhances the convenience of having the generator as a back-up power source. Interruptions are avoided.

The efficiency of the diesel generator can be increased with the help of analysis data and warnings displayed on the generator. ( for example, low fuel, performance issues etc).

The Power Management System helps to optimize the fuel consumption and the performance of the generator with respect to load demand.

Having trouble figuring out what generator is best for your needs? Would you like the assistance of a Generator expert?

Portability and Size

It is also important to consider the portability and size of your genset for transportation purposes and how much space you will need.

Determine whether the generator can be towed or loaded on a truck, check for features such as lifting eyes and forklift slots.

If you are going to be using multiple generators, it is also important to consider if the units can be stacked on top of each other for minimum footprint and access considerations.


Noise emission from a generator can be a problem, besides just irritating in general, you may even have problems with your neighbors.

Noise absorption technology is available for diesel generators that can significantly reduce the generator noise emissions.

A diesel generator can be covered in an acoustically treated canopy which dramatically reduces the dB level (noise), even from within as little as a meter away, the engine noise can be very little. A generator with an acoustic canopy is referred to as a Silent Generator.


The type of generator that you choose will depend on what you intend to use it for, the purpose of purchasing it. Whether you will need to use it as back-up during power outages or as the main source of power etc.

Buying a Diesel Generator is a big investment, which is why careful considerations need to be taken before purchasing. We hope this guide will assist you to make the right decisions.

For expert advice, please do not hesitate to contact us at Waygen Generators. We specialize in manufacturing, supplying and maintaining diesel generators, from 15kVA to 1500kVA+ gensets.

‘Sourcing your Diesel Generators through a trusted supplier goes a long way in ensuring that you choose the right system for your requirements.’

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