Advantech Europe

The risks of not testing your diesel generator

Author : Andrew Keith, Power Prove

22 February 2024

For many facilities, reliability and resilience are safeguarded by diesel generators, which ensure continuous power supply when the grid falters. Here, Andrew Keith, Director of load bank manufacturer Power Prove, outlines some of the main risks that arise if generators aren’t regularly tested.

These dependable back-up power supplies have become indispensable for a wide array of applications, including critical infrastructure and hospitals. But, there’s a silent threat that many overlook – the risks of not testing your diesel generator. 

With extreme weather and supply concerns, last winter the NHS advised hospitals to ready themselves for increased demand, which included preparing for power outages. The continued risk of heavy storms and volatile energy supply mean that service providers across all industries should have a reliable standby power option available, to remain operational.

Fortunately, back-up generators provide a vital solution during power failures. Equipped with an automatic transfer switch that identifies outages within seconds, these generators handle the electrical load, to assure the power supply until grid power is restored. 

However, as these back-up generators are not frequently used, their maintenance is often neglected. This can cause generators to fail, resulting in disruption to critical environments, as they aren’t there to be used when needed. Recently, a Los Angeles hospital experienced an outage where its back-up generator also failed, resulting in patients being transferred to alternative providers by stairs, when lifts and other equipment were unusable. 

Irregular usage and unreliability

Although the exact reason for the LA hospital failure is unknown, there are several potential causes. One of the key reasons behind unreliable back-up generators is when they are frequently run on a low load, or no load at all, without being tested. 

This particularly affects diesel generators, which are available in power configurations designed only for standby use. Although this makes them a popular choice for back-up power, it can also cause problems. Since diesel generators convert the mechanical energy into electrical energy, they are similar to internal combustion engines in that they require a certain load attached to operate effectively. 

This issue can be tackled by routine load bank testing of diesel generators, where the engine, alternator and radiator are run to higher loads. However, as back-up systems are rarely used, testing them is often de-prioritised, reducing reliability and increasing maintenance costs. 

A prevalent risk for diesel generators that are not tested regularly is carbon build-up. When generators are run at low or no load, they cannot produce sufficient temperatures to combust properly, when required. Incomplete combustion results in carbon build-up, a black soot that collects on the generator’s internal components, reducing its working life and increasing pollution. 

Additionally, these carbon deposits can damage the generator’s oil honing grooves, which results in contamination of lubricating oil. As this oil is used to reduce the friction between the generator’s mechanical components, this corrodes and decreases the lifespan of these parts. 

Without regular load bank testing, where the generator is run for many hours, it is very difficult to remove these carbon deposits, resulting in decreased performance and reliability.

Regularity increases reliability

Regular testing limits these risks, and ensures that the generator will perform as expected, when required. A common misconception is that turning a generator on with little to no load is an effective way of testing its performance. However, not only does low loading fail to comply with maintenance standards, but it also often leads to generator ‘wet stacking’. This refers to a condition where unburnt fuel collects in the diesel engine exhaust system, reducing the generator’s integrity and lifespan. 

For compliant, rigorous generator testing, Power Prove designs and manufactures a range of off-the-shelf load bank solutions. For compact applications where accessibility is limited, for example, like a generator situated on the roof of a building, the AC100-CPT’s 30kg weight and pull-handle case make it an easily-manoeuvrable solution for load capacities up to 100kW. 

For more comprehensive testing, the AC300 load bank with the advanced DIGILOAD digital interface provides detailed insights into how the generator responds to load changes up to 300kW. This data can be downloaded to a USB, enabling straightforward analysis of the generator’s performance. 

Summary

In critical environments, be it a hospital, manufacturing plant, or any facility where electricity supply is essential, power failures can have grave consequences. Not regularly using a back-up generator does not mean that its maintenance should be neglected. Assuring the power supply through regular back-up diesel generator testing with a load bank ensures that critical infrastructure remains functional, even during outages.   

For more information on Power Prove’s load bank solutions, please visit the website.


Contact Details and Archive...

Print this page | E-mail this page


Optimal Drive Technology

This website uses cookies primarily for visitor analytics. Certain pages will ask you to fill in contact details to receive additional information. On these pages you have the option of having the site log your details for future visits. Indicating you want the site to remember your details will place a cookie on your device. To view our full cookie policy, please click here. You can also view it at any time by going to our Contact Us page.