Generator Reviews, News, Specifications and Tips

Generator Reviews, News, Specifications and Tips

Tips on Buying a Used Generator


There are many great benefits to purchasing a pre-owned or low-hour used generator. Companies that are both large and small routinely purchase generators that are pre-owned units because it is often the most cost-effective way to buy high-quality industrial assets and/or heavy equipment. However, there are also a number of factors and considerations that must be taken into account before making the actual purchase, which is of course the main purpose of this article.

To begin, it all starts with choosing the right generator for your specific power requirements. For more information on that, see our other article on determining the size of generator. Once you have determined the size you will need, then it's time to start looking at a number of other factors.

Some of the key factors to consider when buying a used generator of any type (diesel, natural gas, electric, propane, gas, etc.):
  • Age, Hours, and Usage
  • Manufacturer history and reputation
  • How well it has been maintained
  • Physical wear and tear on the unit
  • How it performs in a Load Test
  • Who you are purchasing it from (broker vs distributor)

Age, Hours, and Usage:


When shopping for a reliable used generator to buy, one of the first things you can try to check is the hours, age and history of the generator set. First, find out how many hours it has on it, generator engines are usually just like a car and have an odometer reading. It may also be helpful to know what it was used for, and whether it was for the ongoing generation of electric power (prime/continuous), or if it was it a standby machine. A generator that has been used as a standby or backup power source will typically be better maintained and have much less wear than one used as a prime power source. However, be aware that there are many times when the age and usage information is simply not available. Dealers typically acquire generators from things like foreclosures, auctions, and so forth, and they often have no idea where it came from or what it was used for in the past. In those cases, the reputation and technical expertise of the seller is often much more important anyway, since they will (hopefully) be the ones who inspect, tune, rebuild, test, and fix anything that might be wrong before reselling it.


Manufacturer History and Reputation:


While the make and model are not always that critical, the generator manufacturer's history and reputation should definitely play a role when your company is choosing to rely on used machinery. Since you are purchasing a product that you will most likely come to rely on for electric power at some point (whether you are buying a prime or emergency standby generator), now is not really the time to be cutting corners or taking big chances on unknown brands. It's always a good idea to go with a trusted manufacturer who has a reputation for producing equipment that can stand the stress and test of time, and so you can find parts and service that's readily available if necessary. Industry veterans like Caterpillar, Cummins, Detroit Diesel, Onan, Kohler, John Deere, and a handful of others all have a long history of producing high quality equipment that will last for years and years when properly maintained. for years and years when properly maintained.

How Well has it been Maintained?


This is another area where you might not be able to get much historical information, but you can and should check the seller's current level of knowledge on maintaining and repairing diesel engines, power units, transfer switches, and generator ends. You can gauge the seller's current knowledge and expertise in regards to that type of maintenance by simply asking about the procedures they use; if they install and de-install, have dyno-testing equipment on site, have a certified staff of technicians in-house, electricians on staff, and so forth. This is important, since a well-maintained and/or rebuilt generator set will have a much longer life than one that is simply changing hands from a broker to end-user, or end-user to end-user.

Physical Wear and Tear:

  • Visual Inspection

Your next action should be a visual inspection. A generator, like any mechanical device, suffers wear and tear during operation. Check all mechanical components for wear or fatigue. See if any of the mechanical parts have any cracks or corrosion built up. If any part is found to be questionable, it should be replaced, ideally with components recommended by the manufacturer. Every now and then you might run across a generator set that has a different manufacturer's engine and/or end than it originally came with. While that is a sign that something was replaced and it was obviously worked on at some point, it doesn't necessarily have to be a deal breaker as long as the individual components were installed by a certified technician, tested extensively, and it stills come with some type of guarantee from the dealer.

  • Replace bearings and bushings

If this hasn't already been done by the dealer, the bearings and bushings should all be replaced, regardless of their function or condition. This is to ensure that these parts do not cause any damage due to their failure while running the generator set. The bearings and bushings are subject to stress during the generator operation and it is very difficult to test these parts for any stress they have been subjected to during the operation of the generator. Therefore, from a safety point of view, the replacement of bearings and bushings is the best course of action. The same goes for bolts and fasteners.

  • Integrity check wiring and welds

Check the welds for integrity. Also inspect electrical components and windings for integrity. Test wire insulations for breakdown. Any part not up to the mark should be replaced.

  • Load Test

This is a standard test most respectable dealers should have already run, but you should still ask to make sure. A load test helps to determine the overall efficiency in electric power generation. How well the generator responds to varying loads is usually a good indicator of its efficiency under the specified load limits. The kind of electric power output the generator gives will also provide some indication of the general state and well-being of the generator set. The test should check for proper output and frequency. The test may need to be repeated up to three times for added precaution to ensure there are no unexpected power breakdowns.


  • Who you are purchasing it from (broker vs. dealer/distributor)

While anyone on the street can put a generator up for sale in the classifieds, on eBay, and so forth, that's clearly not an ideal situation for a buyer. Industrial diesel generators are complex, finely tuned pieces of machinery that clearly needs to be properly maintained and tested by certified technicians in order for them to operate at optimum efficiency and be there when you need them most. They aren't called emergency standby generators for nothing! And, since most generators come with a substantial price tag, all the more reason to make sure you have professionals and an organization you can trust. Specialized brokers are sometimes an option when you can't find what you need, but be aware that you will be paying a substantial commission on any deal they broker between you and the seller, and that most of them do not have a full machine shop, technicians on staff, or the appropriate testing equipment. Therefore, to eliminate any risks, of course we recommend always going with a professional organization backed by years of industry experience, just like we offer here at Diesel Service & Supply - over 20 years in the business and still going strong!

There are obviously numerous factors and considerations to take into account when buying a used generator, but hopefully this article has helped to at least shed some light on many of the critical components.

If you have any questions or would like assistance in selecting a generator that will meet your specific requirements, you can browse our In-Stock Inventory, search by generator/engine manufacturer, call us toll-free at 855-407-0135, or contact us online and we'll be more than happy to assist.

Used Generators & Engines vs. New What's Right for You?

A wide range of new and used generators and engines are available to potential buyers in the market today. The buying cycle typically starts out with identifying a need (i.e. to power heavy equipment, provide emergency backup, prime or standby power, etc.), then performing research and analysis to determine what your specifications and requirements are. After that, you are usually faced with the all-important decision of whether to go with a new or used engine and/or generator. In order to reach an educated decision and an answer to that, a number of factors must be taken into account, many of which are listed throughout this article.


New Generators

Just as it is when purchasing a new car, the number one reason for buying a new generator is the fact that it comes with a standard manufacturer's warranty. The length and terms of each warranty varies greatly but is typically between one and two years, depending on the intended usage of the generator and/or engine. However, as it is with cars as well, those warranties do not come without a substantial increase in cost. And, depending on the size, make and manufacturer, there may be a long wait time or limited availability so extra time is often required to account for that, especially on the larger generators. For companies who have the time to wait and really want the security a warranty offers for a year or two, new generators can be the best way to go. As it is with any heavy equipment, you simply need to weigh all the pros and cons of your particular situation to determine what the best option is for your needs.

Used Generators

While they do not usually come with a warranty, it is often extremely advantageous to buy rebuilt diesel engines and used electric power generators for a number of reasons. A key one is of course that used generators with low hours on the engines are often available at very attractive prices, and are substantially below the high retail prices of new units. It's even possible to save up to 50% or more by getting a low-hour used generator instead of a new one.

Another key benefit to purchasing a used genset is the fact that they are readily available and can be bought and installed very quickly. There is no waiting because of limited availability and factory lead times, you simply buy it and have it shipped right then and there. Many sellers will even include shipping in the cost of the unit.


Also, because most name brand manufacturers build industrial strength equipment, the risk is negligible. Power generators are built to last and work whenever necessary, as that is their true function in most cases, to always be there when you need them most (as in an outage). And, depending on the age of the unit, it may even still come with a warranty, or at least a guarantee of some type from the dealer. Whenever possible, finding a generator that was previously only used for emergency backup or standby power is the way to go. Backup generators are only run when the prime power goes down so many of these are hardly used at all and have a long maintenance free life ahead of them still.

The only real disadvantage of purchasing a used generator is just that, it was owned and used by someone else. Therefore, you most likely have to go on the word of the seller as to the previous usage, history, and current condition the generator and engine are in. This is why it's important you always consider purchasing from a reputable company who has the technical expertise and infrastructure to properly test, repair and/or rebuild these large industrial machines. Most established sellers will test all their used generators for various loads, but many small brokers and individuals simply do not have the appropriate resources at their disposal. Testing and servicing are both obviously critical. Most tests often come with a verification certificate that details each units functioning. Low-hour used diesel generators ranging in size from 35 kW to 2 MW are often readily available. Low-hour indicates that the generator has been in operation for a reasonably low number of hours. Prices obviously vary greatly based on the kW, HP, hours, manufacturer, KVA, etc., and range anywhere from, $16,000 to $800,000 or more.

Surplus Generators

Surplus machinery is basically new equipment that has been in inventory for a long time or exceeds the original requirement of the purchaser and is not being utilized. Pre-owned surplus generators are sometimes sold by individual companies, auctions, distributors, dealers, and even the military. Companies often sell the surplus to liquidate their excess and/or unused inventory and turn the assets back into cash. As an example, if a company receives fifteen 200kW generators in a bulk deal, and the requirement was only for ten generators, then the five surplus units are most likely going to be sold since they do not need the extra units. If you can obtain a surplus generator at a reasonable price, they are often one of the best and smartest buys you can make. The only downside to purchasing surplus equipment is that sometimes the price is still very close to the original new list price, and if money is a key issue, you could probably save even more by going with a standard low-hour used genset instead.

Generator Ends

Generator ends are the points which determine the smoothness of the voltage that is available from the generator. These are basically the end points of the generator. The ends play the most important role in voltage regulation. The effectiveness of generator ends becomes more important in cases where sensitive electronic equipment is used, such as computers. Used generator ends are available for all specifications. As usual, you can lower your costs by choosing used generator ends over new ones. For reference, the diesel engine and generator ends make up what is referred to as the generator set.

Rebuilt Diesel Engines



Yet another option to consider when buying an industrial engine or generator set is whether or not to consider a rebuilt diesel engine. Rebuilt engines go through a rigorous process that ultimately produces a like-new product in most instances and can be one of the most cost-effective ways of saving money on your investment. To give you an idea of what rebuilding routinely entails, some key steps are listed below:

While rebuilding engines, engine cores are completely disassembled and all parts are cleaned in a chemical vat. Engine parts are sent out for testing, inspection and rebuilding. This whole procedure is extremely elaborate and involved.

Cylinder blocks are also checked for surface cracks. Cylinder bores, counter bores and crank bores are checked and repaired if needed. Water passages of the cylinder blocks are pressure tested. These crankshafts are then are measured and polished or machine ground to standard manufacturer specifications.

Connecting rods and blowers are replaced or remanufactured. Water pumps and fuel pumps are remanufactured using new bearings, seals and shafts. Other subassemblies and parts are also remanufactured to strict factory standards and specifications. Prior to the release, fuel pumps are also bench tested.

The engines are reassembled using all new bearings, seals, gaskets and numerous new consumable parts. Complete engines are tested for various loads on an advanced dynamometer. Horsepower output, rpm, oil pressure, crankcase pressure and air box pressures are recorded along with engine specifications and supplied with a startup inspection report. Engines are then rust proofed and weatherproofed with a red oxide layer or with enamel paint.

Complete care is taken to ensure that the rebuilt engine is literally almost as good as new when the process is finished. This is why it is often a great idea to seriously consider purchasing a rebuilt diesel engine for most applications. The only real downside to the process is that you need to make sure the seller is a trustworthy and professional source who has the technical expertise and personnel to properly perform this process and handle all the meticulous details. Of course, here at Diesel Service and Supply we have some of the industry's top diesel technicians and have been rebuilding diesel engines for over 23 years.

New vs. Used - Summary

In summary, as you can see, it is obvious that a used, rebuilt, or surplus generator and/or engine can typically provide much more value for your money and should therefore always be a consideration. However, as it is with any large industrial/commercial purchase, there are a number of factors to consider and weigh before making your final choice.

Caterpillar Diesel Generators: World Class Commercial Power


Caterpillar Diesel Generators: World Class Commercial Power


For generations, Caterpillar has been the brand of generators you can trust. Known worldwide for their high quality heavy equipment, machinery, and generators, Caterpillar offers customers many years of reliable safety and outstanding service. Their line of commercial generators provide thousands of hours of use before any maintenance is even required, making them a wise choice for people in the market for everything from small to large scale generators. Caterpillar offers a wide variety of large and small generator sets as well, with power ranges from 7 kW all the way to 16,200 kW, giving them a serious edge in the generator market. 

Their generators are easy to specify, and easy to purchase. With fuel costs becoming a major decision factor, Caterpillar has you covered with world-class fuel efficiency, saving you money on high refill costs. In addition, all of Caterpillar’s generator sets have plenty of options to choose from including a wide range of various attachments.

When you need a strong backup power generator that can provide solutions for your business, go with Caterpillar. Not only are their generators world class, but the components included are top quality as well. Batteries, fuel tank bases, security casings, air cleaners, electronic governors, and much more are all available from the Caterpillar line to help make your generator run even more efficiently. 

With a great track record, a huge customer base with lots of satisfaction, and reliable service, Caterpillar generators are an excellent choice when it comes to your backup power needs. Whether you own a small business or are in charge of a large corporation, Caterpillar has generators to suit your own personal needs. Diesel Service & Supply is a generator reseller and distributor who carries both new and used Caterpillar generators, so be sure to ask us about purchase options today.

For years, Caterpillar has been a worldwide recognized brand name. Their line of generators provides reliable service for your prime and backup power needs. Whether you own a small business or a large one, you can count on Caterpillar generators to give you the security of a constant power supply. Buying a used Caterpillar generator is not only cost effective, but it can give you hours of power with little to no maintenance.

The Caterpillar brand assures you that you’ll get the service you’ve come to expect. Look for additional Caterpillar used parts and accessories as well such as switches, casings, and cooling systems, just to name a few. Hospitals, data centers, mining facilities, and more have come to rely on the Caterpillar line of generators, both new and used. A rebuilt Caterpillar generator provides the same excellent service that the new ones do, while saving your company a lot of money.

Many companies have chosen used Caterpillar generator sets to provide them with the power they need to continue functioning in times of power loss. Their generators run clean, saving you money on fuel costs, and also providing a clean environment as well. In times of emergency, rely on Caterpillar used generators to give you the edge in your business. 

The name Caterpillar is synonymous with strength, quality, and reliability. By purchasing a used Caterpillar generator from Diesel Service & Supply, you can be sure you’ll get the service you need for all kinds of applications. From industrial use to home use, Caterpillar has been a household name for many generations. Talk to one of our knowledgeable sales staff about purchasing a used Caterpillar generator, and be prepared to have peace of mind knowing you’ve chosen a quality brand.

Top 10 Industries that would be Affected Most by a Power Outage

Data on electricity consumption in the U.S. by various sectors, as provided by the Energy Information Administration (EIA), reveals that residential usage tops the list with 36 percent, followed by 32 percent utilization by the commercial sector, 29 percent by the industrial sector and the remaining is attributed to miscellaneous usages. In an age where functioning of businesses in inconceivable in the absence of electrical power, even a brief power outage can cause tremendous losses of productivity, material and revenues. The degree of impact caused by a power failure to an individual company varies by industry and the nature of applications. It can range from being disruptive to life threatening.

Here’s a quick look at industries and business functions that are severely hampered by power failures:


1. Manufacturing Industries


Power outages bring production lines to an abrupt halt. This may translate into loss of material, breakdown of machinery, and loss of productive time. This may also cause supply chains to shut down altogether. Visit this article, Diesel Generators Keep Business Operational, for further details on how power outages can affect the manufacturing industry.

2. Financial Corporations

It is not difficult to imagine the chaos a power outage can cause to the stock market. In an industry where millions of dollars can be made in profit within a fraction of a second, power outages render financial corporations unable to carry out crucial transactions on time. This is synonymous with millions of unrecoverable dollars per minute of downtime followed by several additional hours of recovery time.

3. Consulting and Information Technology (IT) Services


Consulting services firms and software development facilities house hundreds of highly paid professionals. Even a brief period of downtime leaves them stranded and results in loss of billable hours. In an age where IT operations are an organization’s window to the rest of the world, power outages result in crashed computer systems, lost data and abrupt termination of communications with clients. This is often followed by several weeks of effort spent in recreating hundreds of man-hours of work. Programs and data may get corrupted resulting in software recovery operations that may not be resolved for weeks.

4. Data Centers


Data centers form the backbone of operations for several organizations such as financial services firms, insurance companies, and IT services firms among many others. Power failures here can cause an irrecoverable loss of thousands of records stored over the years and disrupt ongoing transactions as well.


5. Perishable Items


Pharmaceutical industries, petrochemical industries and food processing plants rely heavily on uninterrupted availability of power for storage and preservation of perishables that have extremely limited life spans. Power outages can cause in-process products worth several millions of dollars to be discarded due to damage, spoilage or contamination.

6. Control Centers


Traffic signal operations, public transport systems like the railways, control centers for air traffic management, telecommunications and utilities, all rely heavily on continuous power supply for smooth functioning. Disruption in such critical operations can jeopardize the safety and security of millions of unsuspecting consumers in an instant.

7. Medical Facilities


In hospitals, patients’ lives are delicately supported by health monitoring systems. The following article, Role of Diesel Generators in the Healthcare Industry, provides a more in depth look at the negative effects of power interruptions in the healthcare industry. Any discontinuity in the normal functioning of medical equipment can directly translate into loss of many lives.

8. Military Operations


Power outages render valuable equipment, weaponry and even personnel, defenseless, and hence, exposing them to the risk of attack.


9. Entertainment Venues


Cancellation of money-spinning events even for brief periods of time equates to huge losses of revenue for entertainment facilities. For instance, an extended power outage in a casino can translate into losses of more than US$ 1mn per day. In addition to resulting in forced losses of revenues, abrupt termination of routine operations can also become hazardous to visitors and operating personnel as well.

10. Safety and Security


In addition to causing inconvenience, power outages can endanger the safety of the common man. People trapped in or out of buildings with automated access control systems, elevators that come to a sudden halt and are plunged into darkness, fire alarms and water sprinklers that cease to function, inability to communicate via phone or email with emergency services – these are just a few examples of power outages becoming more than just a nuisance factor and threatening to endanger the safety and lives of millions of people simultaneously.

Electrical power outages, surges and spikes bring about more than $150 billion in annual damages to the U.S. economy. Every year, an estimated $104 billion to $164 billion goes down the drain due to power interruptions, while another $15 billion to $24 billion is lost on account of poor power quality such as voltage fluctuations, power surges and spikes. Specifically, industrial and digital business firms suffer losses amounting to $45 billion annually. Some industries, such as manufacturing, can lose as much as $6.45 million per hour of downtime. The benefits of investments made in necessary power backup arrangements far outweigh the shocking costs related to irreparable damages and irretrievable loss of revenues caused by downtimes.

Why Buy a Generator: Standby / Emergency, Prime, or Continuous Power Supply

There are numerous reasons for individuals or businesses to own their own backup/standby, prime, or continuous power supply generator set(s). Generators provide an added level of insurance to your daily routine or business operations ensuring uninterrupted power supply (UPS). The inconvenience of a power outage is rarely noticed until you are the victim of an untimely power loss or disruption.

Back-up Power for Individual Residences

Individuals can avoid the inconvenience of power outages by purchasing a small backup generator. Electricity is essential to maintain properly functioning lighting, electronic entertainment equipment, household appliances, HVAC, and security systems. The inconvenience of losing power may not be realized in your pocket book but rather in the safety and well-being of your family.

Houses and small residences only require a small amount of backup power, typically in the neighborhood of 5-10 kW. These gensets can typically be purchased for less than $6,000. Obviously large residences (> 6,000 sq. ft.) may require a bit more power, which will increase the cost slightly, but still is highly affordable considering the benefits of owning your own power supply.

Emergency/Standby Power for Businesses

As a business owner, an emergency standby generator provides an added level of insurance to keep your operation running smoothly without interruption. Luckily, the decision to purchase a generator is easily made by performing some basic financial calculations:
  • First, you must determine how much money your business generates on a daily basis. Only consider the revenue that is strictly dependent on power supply (i.e. phones, computers, process equipment, etc.).
  • Next, factor in any capital equipment or assets that depend on a power supply in order to maintain its value (i.e. perishable goods, etc.) You must also consider costs that are associated with a start-up or shut-down of a process or manufacturing line. Costly startups and shutdowns due to power outages can prove to be very costly.
  • Finally, add up all of these costs and multiply it by the number of power outages you have each year. This will give you your yearly operating losses due to power disruptions. Dividing the cost of the generator by these potential losses will determine how many years it would take for the generator to essentially pay for itself.

Costs alone should not be the driving factor in purchasing an electric power genset. Another advantage to having a localized backup power supply is to provide a consistent power supply to your business. Generators can provide protection against voltage fluctuations in the power grid can protect sensitive computer and other capital equipment from unexpected failure. These expensive company assets require consistent power quality in order to function properly. Generators also allow for end users, not the power companies, to control and provide a consistent power supply to their equipment.

End users also benefit from the ability to hedge against highly volatile market conditions. When operating in a time-of-use based pricing situation this could prove to be a huge competitive advantage. During times of high power pricing, end users can switch the power source to their standby diesel or natural gas generator for more economical power.

Prime and Continuous Power Supplies

Other individual and business facilities require continual or constant power supply for long periods of time in remote locations. This is where generators are depended on to provide necessary prime or continuous power in many applications. Prime and continuous power supplies are often used in remote or developing areas of the world where there is no utility service, where available service is very expensive or unreliable, or where customers just simply choose to self-generate their primary power supply.

Prime power is defined as a power supply that supplies power for 8-12 hours a day. This is typical for businesses such as remote mining operations that require a remote power supply during shifts. Continuous power supply refers to power that must be continually supplied throughout a 24 hour day. An example of this would be a desolate city in the remote parts of a country or continent that is not connected to an available power grid. Remote islands in the Pacific Ocean are a prime example of where power generators are used to provide continuous power for the residents of an island.

Electric power generators have a wide variety of uses throughout the world for individuals and businesses. They can provide many functions beyond just supplying backup power in case of emergencies. Prime and continuous power supplies are needed in remote areas of the world where the power grid does not extend to or where power from the grid is unreliable. Browse our inventory of gensets today and find the right type of generator for you!
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