5 Sizes Of Diesel Generators

When considering purchasing a diesel generator, many people are not sure which size they should buy. First, we need to cover the different sizes of diesel generators available.

What Determines Diesel Generator Size?

Diesel generators are sized based on two main criteria: power output and fuel consumption. Power output is measured in kilowatts (kW or kVA).

Diesel generators range in size from 20 to 3000 KVA (kilo volt-amperes, or 1000 volt-amperes) in power. For a regular home, a standby generator of 100 KVA or less is likely enough. For industrial applications, anything between 100-3000 KVA will work, depending on the energy requirements.

Fuel consumption is typically measured in gallons per hour (gph), and diesel generators consume between 0.25 gph and over 200 gph.

Diesel generators can be used for a variety of applications including backup power, prime power, construction power, agricultural power, and more. Depending on the application(s), different sizes will be required.

Diesel Generator Sizes

Many diesel generator sizes are available to choose from that will fit the user’s application and power needs. The list below should give you an idea of the size ranges available:

  1. 10-50 KVA
  2. 50-250
  3. 250-600
  4. 600-1250
  5. 1250-3000

For a regular home, a standby diesel generator of 100 KVA or less is likely enough. For industrial applications, anything between 100-3000 KVA will work, depending on the energy requirements.

Diesel Generator

The Most Important Factors To Look For

Backup Or Primary Power Source?

Another important question to ask is “what is the diesel generator used for?” A diesel generator can be used as a primary power source or a backup for a home or facility. If you only need a backup power source for your home to power critical appliances, then a smaller one will be fine. However, if you have a large warehouse or shop that runs heavy machinery, a larger generator is best.

Diesel Generator Load Sizes

There are factors related to loads that diesel generators can provide. Terms you should be familiar with are running load (KW) and starting load (KVAr). Deciding on the right diesel generator requires knowing what type of load it will be supplying.

Available Space

Another important factor to consider is the space available to install the generator. Your home will need to have a side area or garage that can fit the generator on a concrete or wood base without blocking access.

Sound Restrictions

It is also required to know if there are any sound restrictions in your area that a diesel generator could cause trouble with. You don’t want to make the neighbors angry when you run your generator!

How Often It Is Used

Knowing how often you will need your generator should also factor into your decision. If you will be running it often, it should be of high durability and capable of heavier loads.

Power Requirements

It is necessary to list your power requirements, such as appliances, lighting, computers, etc. so you know for sure what amount of power will be needed. Then choose a diesel generator that supplies at least 5-10% more power than you need.

Single Phase Or 3 Phase?

There are different phase types for diesel generators. It is important to know if you require a single phase or 3 phase unit to supply power. Single-phase power is made up of a power circuit with a two-wire alternating current (ac). 3 phase power is a power circuit with a three-wire (ac) that provides signals at a distance of 120 electrical degrees. If you need a generator for a residential home, then a single-phase is probably best. If you own an industrial facility and need a generator, then a 3-phase unit is likely optimal.

The Largest Diesel Generators

The largest diesel generators are those that have the biggest engines. The largest engine in a diesel generator is the Wärtsilä-Sulzer RTA96-C, which is 14 cylinders, 4 strokes, turbocharged, and has a displacement of 960cm3. The engine weighs approximately 2300 tonnes and produces power of ~35,000–80,00 kW of actual power. These generators are designed to be used on large container ships and cannot be purchased by ordinary homeowners.

Another example of a very large and powerful diesel generator is the Cummins C3000D5 with a 3000 KVA.

To Close

There is a range of sizes of diesel generators available to purchase for both homeowners and businesses. Before deciding which one to buy, make sure you have the space and the energy requirements that fit the model you are looking at.

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Nick Klamecki, Author
About Nick Klamecki, Author

Nick Klamecki is a certified Fire and Workplace Safety expert with 15 years experience in product research and testing. He has a degree from U.C. Davis, is an active outdoorsman and spent years ensuring the safety of special needs children. Nick researches and tests workplace, industrial and safety products and provides advice on their safe use. Learn more about Nick here or connect with him on LinkedIn | Medium