If, like most of us, you use a diesel generator as a backup power source during electrical outages, you need to understand something about Data Center engines and how to keep them running sweetly, starting automatically and reliably. It is horribly career limiting to spend your shareholders money on some equipment that you only need once every couple of years and when you need it, it won’t start.

Lets start with the basic principles:

A Data Center engine is a pretty standard diesel engine, albeit one that is attached to a generator set and is designed to have a long and reliable life. Engines can last 20 or more years, giving reliable service if they are looked after properly.

It is important to know that they do not last forever and eventually need to be replaced. Diesel engines depend on having clean and functional lubrication for long and reliable life. The lubricating oil and filters must be replaced at regular intervals as specified in the manufacturers documentation.

The odds are high that your fuel that’s supposed to operate the engine fails to meet specifications because of water, sulphur and algae contamination. Diesel can be heavily contaminated by water from condensation or by particles from poor transportation and storage.

Poor diesel fuel quality is another problem driven by the success of diesel power and increased demand for the product. Refineries and fuel depots have reduced production to delivery cycle times so that fuel rarely remains in a refinery’s storage tanks long enough for water to naturally separate and settle. The impact is that we often receive fuel with significant quantities of water.

Why is water a problem? Diesel power is very different from petrol in that it is both a fuel and a lubricant and coolant. Water not only reduces the effectiveness of diesel but can cause problems of its own. Water can cause excess wear on injectors and in extreme circumstances can blast off the tip of the injector as it turns to steam in the extreme conditions in the combustion chamber.

So what can we do? As water is heavier than diesel, it will naturally separate over time, the water can be drawn off from our storage tanks at regular intervals to prevent ingress to the engines. Water can also cause corrosion and algae buildup by adding iron oxides to the nutrient rich nitrates, sulphates and water in the tank.

A real problem with standby use of engines is that fuel can be left for many years before being used. This allows contaminants to build up and sludge to form, that can contaminate engine lubricants. At BT we avoided this by coming off Grid at times of high electrical load, running on our standby generators and ensuring that the fuel was cycled. The added benefit was that the electricity companies charges us less for our power as we didn’t need them at times of highest network load.

Many data center operators run regular on load tests of their generator sets, often with dummy loads that just waste the energy. Why not come off grid and reduce your electricity costs during the engine test?