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Diesel Generator Questions and Answers


Why buy a Diesel Generator?
Diesel generators are more reliable. The easiest way for me to explain it is this. Diesel fuel is basically a light-grade oil. Inside any internal combustion engine, there are many moving parts that create friction. Gasoline and propane are solvent-based fuels which promote friction and wear. Diesel, being a lubricant, reduces friction and wear. If you ever need to do work on a Diesel engine, they are simple. All you need to make a Diesel run is air-compression and fuel. Diesels don’t need sophisticated (and failure-prone) ignition systems; no spark plugs, no points and no carburetor!


How long will a Diesel generator last?
With proper maintenance, a high-quality Diesel generator will last indefinitely. It is important to change the oil regularly and keep the air filter clean. Clean fuel is extremely important.


What about the generator end. How long will it last?
Although it is often referred to as a generator, we only use brushless alternators. The beauty of a brushless alternator is that it only has one wear item – a sealed ball-bearing that is rated for 100,000 hours.


What about 3600 RPM Diesel generators. Why are they cheaper?
3600 RPM Diesel generators are sometimes referred to as portable or throw-away Diesel generators. They get their power from speed rather than displacement. For that reason, they weigh less than half of an 1800 RPM Diesel Engine. The alternator on a 3600 RPM Diesel generator spins twice as fast so it can get by with less than half of the copper of an 1800 RPM alternator.  Due to the higher engine speed, these 3600 RPM generators wear out much sooner.


Can I run my Diesel generator on Bio Diesel or other alternative fuels?
Yes, a Diesel generator will run on almost any type of oil. They will run on anything from used motor oil, vegetable oil, refined bio Diesel, you name it. Now, should you run your Diesel Generator on any oil-based substance it will run on? If it’s an emergency, yes. However, make sure it is clean. If it is not an emergency, select your Diesel fuel alternatives carefully.


Why should I buy my Diesel generator from Hardy Diesel?
We have been selling quality Diesel Generators wholesale direct since 1977. We have learned a lot during this period of time. Some things can be learned in books. Competing successfully in the wholesale generator business is not one of those things.  During the last 31 years, we have seen a lot of mail-order Diesel generator companies come and go, and when they fail, they leave a trail of unhappy customers in their wake.  What differentiates Hardy Diesel from our competitors is that we provide well-engineered, high-quality systems at a reasonable price.  


How do we manage to provide superior products at such affordable prices?
Hardy Diesel is family owned and operated and we continue to do business from our 26 acre ranch 20 miles east of San Diego CA . We have no fancy showroom and pay no rent. We welcome all customers to come by and visit us. Another advantage: no one here has ever figured out how to wear more than one pair of pants at a time! Low overhead is the key.


Does Hardy Diesel sell gen sets made with engines or generators from China or India ?
No, although we have nothing against these countries or the people who live and work there, we do not use their products in our systems. Trust me, we have tried all of them and there are many problems associated with Diesel engines and generator sets from those nations. Sure, the price is attractive and they’ve found ways to skirt around  U.S. environmental laws, but in the final analysis, it’s just not worth the risk to your family, live-stock, home or business. Do yourself a favor and don’t support the companies who pedal this gear; they care so little about the safety and satisfaction of their customers and they give our industry a bad name!


Why do some companies advertise slow Diesels generators with 3600 RPM alternators on them?

3600 RPM alternators are very cheap to buy. With belt-drive, you can slow an engine down below 1800 RPM and speed up a generator to 3600 RPM and still get 60Hz. We don’t resort to short-cuts like this. Belt-drive, in itself, is okay if properly tensioned, however we would never couple a slow Diesel to a 3600 RPM alternator because they are capacitor-regulated and often fail. Two-pole or 3600 RPM alternators are sometimes referred to as “throw-aways” because when they fail, they are simply not worth rebuilding. Capacitor-regulated alternators also have a very low motor-starting ability. We recommend you avoid these types of Diesel generator sets and the companies who sell them.


Diesel Generator kW (General Info)


Diesel generator kW (k=1000 W= Watt) is typically produced at lower RPMs. Example 8kW =8000 Watts. It takes 1.5 horsepower to make one kW. Turning at a slow 1800 RPM a Diesel generator kW requires large displacement. Most gas and even some Diesel generators run at 3600 RPM. This is considered high speed throw away generators. Initial cost on these is low however they ware out quick and are not worth fixing. We only sell Diesel generators that run at 1800 RPM. Diesel generator kW produced from 1800 RPM engines and generators last almost indefinitely. That is why they are sometimes referred to as investment grade.


Wire sizing chart


I live in another country will your Diesel generators work in my country?

Yes, click here for world voltage frequency chart by country we can configure your unit for any voltage and frequency needed anywhere in the world. In most cases however, 50 Hz will reduce output by 15 % due to decreased engine speed.