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Diesel Generators Buying Guide

The invention of the Diesel Generator can be credited to two separate individuals: Michael Faraday of England, who invented the first functional generator and Rudolph Diesel of France, the inventor of the Diesel Engine. Eventually the electric generator and diesel engine were combined to create a functional diesel generator which was designed with the purpose of supplying off the grid electrical energy for industrial and emergency purposes or as a main power source.

In the following article we shall cover some of the basics regarding how diesel generators function and their purpose, along with some recommended Surplus Record tips and tricks to assist with the purchasing process of used/new diesel generators for sale on our platform. We shall also include some notes that a buyer should be aware of when on the lookout for used diesel generators for sale.

What is a Diesel Generator?

The diesel generator is a combination of the diesel engine and electric generator designed with the intention of converting the energy found in diesel fuel into usable electrical AC energy. They are an independent energy system which requires the introduction of diesel fuel to function much like a diesel engine.

Other Types of Generators 

Natural gas generators 

Natural gas generators use natural gas as fuel to generate electricity. These machines convert the energy released by the combustion of natural gas into electrical power. Natural gas generators are commonly used as backup power sources for homes, businesses, and industrial facilities, as well as in remote locations where access to the power grid is limited. They are known for their reliability, efficiency, and low emissions compared to other types of generators. Natural gas generators provide a cost-effective and convenient solution for generating electricity in a variety of settings. Natural gas generators produce much lower emissions compared to diesel generators and generally require less maintenance compared to diesel generators, as they have fewer parts and operate at lower temperatures. 

Dual fuel generators 

Dual fuel generators operate on two types of fuel, typically gasoline and propane or natural gas. They offer the flexibility of using either fuel source depending on availability, cost, or preference. Dual fuel generators are commonly used as backup power sources as well as in remote locations where access to a reliable fuel source may be limited. Dual fuel generators can produce lower emissions compared to diesel generators, especially when running on propane or natural gas. Overall, dual fuel generators can provide a reliable and cost-effective solution for generating electricity in a variety of settings, especially in areas where fuel availability and cost fluctuate. 

Diesel generator diagram
Details of a diesel generator

30kw diesel generator
30 KW diesel generator for sale on Surplus Record by the team of dealers at Generator Source

On the Surplus Record catalog one can view:

How does the Diesel Generator function?

You should begin by viewing our Diesel Engine Buyers Guide to understand how a diesel engine functions. When the diesel engine is in operation, it will rotate the shaft of an alternator’s main rotor, which contains a magnetic field, and create an AC current (electricity). The AC current is directed through a series of cables which can be connected to the desired output source ready for general usage. The power and speed of the diesel engine will change the amount of power generated, the greater the horsepower and the faster the rotation = the greater the voltage generated.

Uses and Applications

The Diesel Generator is an extremely useful tool that can be used in a variety of different ways. Most often we will see their usage throughout construction or agricultural industries as industrial power sources for heavy duty equipment. Equally they can be seen as an emergency power source or a remote energy source where other options are not available. Other uses or applications could include:

  • People who live off-grid and need reliable power sources.
  • As a backup for on-the-grid or solar power systems.
  • For use at large-scale events such as concerts or sporting events.
  • As a continuous power source on remote mining, construction, or oil sites.

For crucial industries such as the production of food or medical services that require continuous operation and need an emergency power source in the case of power outages.

Important Considerations Before Buying Diesel Generators

Inspect the Oil of the Diesel Engine

Perhaps one of the most important steps to consider when viewing a used generator for sale is the condition of the diesel engine’s oil. Start by removing the dipstick (or ask the owner to send you a video/picture) to view the color and appearance of the oil. If there is white coloring in the oil or milky characteristic about the oil’s appearance, it can mean that there are internal problems with the engine, and it may need replacement.

Fuel Consumption

When considering the fuel consumption of a new or used diesel generator for sale, the result of efficient or inefficient fuel consumption will depend completely on the generator’s maintenance history and size of the generator (KW). Irregular maintenance results in inefficient fuel consumption as components can be forced to work harder or irregularly and the excess of kilowatts also corresponds to the same. For reference, with a half load capacity, an 8kw generator will consume approximately 1.3 liters of diesel per hour vs a 400kw generator which will consume an excess of 62.4 liters per hour of use. The conclusion is to purchase a generator with a reliable maintenance history and kilowatts to match your requirements of use.

Kilowatts

As mentioned, the available energy output should strictly match your requirements of usage. The chart below is an excellent resource to compare fuel consumption vs kilowatts of the generator. Also, for example and to assist with selecting the correct generator: an AC unit will require a generator of approximately 15 KW/h, a welder approximately 10 KW/h, a computer approximately .2 kw/h and a 1 horsepower air compressor approximately 3000kws. Surplus Record’s catalog contains new and used diesel generators for sale ranging from 2 kilowatts to 2000 kilowatts or more.

Control Systems

These can vary and should be investigated thoroughly before purchase. A generator control system can support a variety of features including system warnings, fuel and power consumption, notifications of performance and more. Request that your dealer provide a brief of the system capabilities of the used or new diesel generator for sale of your interest.

Surplus Record: Tips and Tricks

To assist you further when searching for used diesel generators for sale on our platform, we have attached five tips and tricks.

Diesel generator search
  1. Use the KW Filters at the top of the Diesel Generator category page! This allows you to instantly filter on a range for the Kilowatt size of the generator you need!
  1. Make use of our Location Settings: At the top of the page, when on the list for your desired piece of equipment/machinery, enter your desired location and you’ll be taken directly to what we have available in your area.
  2. Looking for an Auction? On the listing page, select the blue checkbox on your right which says “Auction” and you’ll be taken to our available products for sale via auction.
  3. On a Budget? Select the toggle “Sort by Relevance” and then click “Price low to high” to view our cheapest to most expensive products for sale.
  4. Don’t forget the Search Bar: Already know what you are looking for? Utilize our search tab at the top of your page to find specific listings out of hundreds available.

Quick Access: Diesel Generator Dealers

Quick Access: Dealers that Specialize in Diesel Generators

Quick Access: Diesel Generator Manufacturers

Our top manufactures available at Surplus Record for used diesel generators include: 

Need More Help? Or further information about Diesel Generators? Head on over to the “Wanteds” section of our website and select “Buy” at the top and “Generators & Engines” for the industry. Fill out the form and a dealer that specializes in generators will get back to you ASAP. It’s free to do, and our dealers are happy to help!

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