Diesel Generator FAQ: 1500rpm and 3000rpm Differences

In the first of our diesel generator FAQ series, we address the big questions that many customers have about the differences between 1500rpm and 3000rpm diesel generators. 

When purchasing a diesel generator for the first time, it's important to know exactly the differences between these two types of generators mean for you, and how they impact the performance and durability overall.

Let's start with the most obvious question first... 

What Is The Difference Between 1500rpm and 3000rpm Diesel Generators? 

The rpm figure is related to the revolutions per minute that a diesel engine experiences.

A 3000rpm diesel generator will have twice as many revolutions per minute as a 1500rpm diesel generator. 

The main consideration when choosing between a 3000rpm and 1500rpm diesel generator is the amount of time you need your generator powered for, and the overall life expectancy you’d like to get out of your generator. 

Think of it this way: if two identical cars were both driven at 70mph on the motorway in 3rd and 5th gear respectively, which engine would you expect to be in better condition by the end of the year? Unsurprisingly, it would be the car that was constantly in a higher gear which produced less revs and stressed the engine less. This applies to generators, too. 

A 3000rpm generator is ideal for regular standby/backup power, as well for agricultural applications such as mobile field repairs. On average, a well maintained 3000rpm generator should last for 2,000 - 3,000 hours

Because 1500rpm diesel generators have slower running engines, which are less-stressed than the smaller models, they’re suitable for static installation for daily prime power, as well as for standby use. The lifespan of one of these generators can last for 10,000+ hours

Does That Mean 1500rpm Diesel Generators Are Always Better?

No, it will depend on your requirements. 

A 1500rpm generator will cost significantly more than a 3000rpm generator and usually produce much more power.

If your power requirements aren't too high, and you don't require a constant supply, a 3000rpm is the more cost-effective and sensible option.

In fact, under-loading a generator is just as problematic as overloading one, so it's important to get the right size generator for you. 

Are There Any Size Differences Between 1500rpm and 3000rpm Diesel Generators?

Yes, 3000rpm generators are much smaller than 1500rpm models. This makes them more appropriate for small homes or businesses where space is limited.

3000rpm generators are also often fitted with handles and wheels, making them relatively portable compared to the larger, static 1500rpm generators. 

Are 3000rpm Diesel Generators Louder Than 1500rpm Diesel Generators? 

Generally, not much. 

Although you would think an engine which was revving twice as much would be much louder, high quality diesel generators are fitted with sound attenuated panels. 

These diesel generators are referred to as 'silenced' with noise reducing canopies that dramatically reduce the noise levels of the units. 

Are Running Costs Different Between 3000rpm and 1500rpm Generators? 

Running costs will vary depending on the power output of the generator and the loads which are applied to them when running. 

The lower the load, the less stressed the engine and the more economic the running will be. 

Both types are also capable of running on red diesel, which is significantly cheaper than road diesel. 

What Is The Right Diesel Generator For Me?

Hopefully now you understand the difference between 1500rpm and 3000rpm diesel generators, but if you’re still not sure which one is right for you then don’t worry. Give us a call on 01437 700123, email us at info@thepowersite.co.uk or use the live chat in the bottom right corner to have a chat with us. We’ll take your requirements into consideration and help you find the perfect diesel generator for your needs! 

You can browse our full range of diesel generators here.