Plan, maintain and test your back up power system

18 April 2011
Lessons from Losses 3/2011. The purpose of backup power systems is to safeguard power supply in the event of cuts or failures in the power supply network. Fortunately, power failures in Finland are not caused by earthquakes of magnitude 9.0, but by snow or storms, for example. Power cuts are common, and even short power failures can cause extended production stoppages, loss of profit and even hazardous circumstances, unless the company has a reliable backup power system.

According to Ekström Oy, a Finnish company that imports diesel generator sets for backup power systems, there are approximately 45 000 backup power units installed in Finland. Around half of these are located in industrial plants and the other half in public premises, such as central, regional and local government offices, hospitals, airports, commercial centres, hotels, financial institutions and data communication hubs.

“According to our experience, maintenance practices vary, and it is frightening to think what could happen if maintenance is neglected or the maintenance technicians do not know their job. What happens if the backup power machine doesn’t start up in an emergency?” asks Robbie Lindberg, Chairman of Ekström Oy’s Board of Directors.

Is your maintenance staff competent?

Todays back up power systems are technically advanced, individually tailored systems. As companies increasingly outsource their facilities maintenance to servicing and facility management companies, they should ensure that the service provider is sufficiently skilled with respect to backup power systems. The correct maintenance of backup power systems requires skilled professionals who are able to assess whether the backup power system operates as expected. A general maintenance technician can examine the equipment visually, that’s all. System manufacturers and importers provide up-to-date training for maintenance personnel.

“It is essential to understand that backup power system maintenance is much more than just engine servicing; rather, the maintenance team has to manage the various sub-areas of the system as a whole,” emphasises Jarmo Oksanen, Marketing Manager at Agco Sisu Power Oy, a company manufacturing backup power systems. In regards to maintenance, the correct operation of batteries, for example, must be verified through load tests. Furthermore, it must be ensured that the generator, network and backup power switches, as well as the various alarm systems, such as the oil pressure and engine cooling liquid temperature, are working correctly.

Do not wait until a failure

“Too often, companies do not contact us for assistance until a failure has occurred in their backup power system. In many cases, such failures could have been prevented altogether through professional preventive maintenance measures. However, it often turns out that neither the customer company nor their regular maintenance supplier knew what should have been done. By analysing the historical data recorded by the monitoring system, it is often possible to conclude which tests have been performed in connection with maintenance,” Mr Oksanen explains.

Naturally, a manufacturer’s guarantee is only valid if the maintenance has been handled by persons authorised by that manufacturer. However, companies may choose not to use qualified maintenance personnel in an attempt to save on cost. This could save a few hundred euros each year, but can those savings cover the loss or damage arising from the fact that the backup power system fails to start up in an emergency? And who will take responsibility for this? 

Testing at full load and regular maintenance are vital

Companies that have not experienced any power cuts or failures may completely forget to test and check their backup power systems. Risk engineer Ville Valta from If recalls an event in which a single defective battery of the fifty batteries in a backup power system crashed the entire system, resulting in significant expense for the company. It was later discovered that the backup power system had not been tested at all.

“Based on our experience, we want to emphasise that test start-ups and runs must be performed at full load and up to the normal running temperature. This enables us to see, for instance, whether the cooling system is working. The testing conditions must be as realistic as possible. It should also be noted that a small number of operational hours does not guarantee that the system will function properly when needed,” Mr Valta underlines.

Plan together with professionals

Currently, the world’s best known four diesel generator sets used for backup power supply are probably those at the Fukushima nuclear power plant in Japan, due to the earthquake and tsunami of 11 March 2011. According to STUK, the Radiation and Nuclear Safety Authority Finland, the diesel generators started up smoothly, when the earthquake disconnected the plant from the national power grid, and they ran for an hour before fate intervened.

According to the information provided by the Japanese, their risk planning had prepared for a tsunami of 10 metres in height, including a considerable safety margin. Even the most pessimistic assessments in the world would not have anticipated that a 14-metre tsunami would roll into the plant area, swamping and crashing the entire backup power system.

This case demonstrates the importance of good planning. Backup power systems must be able to function under exceptional conditions. Their planning and design require experts in various fields – from experts in electric and backup power systems to professionals specialising in risk management and loss scenarios. It is worthwhile hiring experts as early as the project planning stage. Every corporate environment is unique, requiring the careful planning of a suitable, correctly proportioned back up power system, including any possible auxiliaries.

Useful advice for planning is provided by system suppliers and experts at insurance companies. The day may come when the continuity of a company’s business and the jobs of its employees, even their lives, could depend on the correct functioning of a backup power system.

Backup power and insurance – the best form of risk management

If a device breaks down due to a power failure, the subsequent loss or damage could be compensable under an insurance policy, depending on the scope of the corresponding cover. However, if a company has to take time-consuming measures to shut down and restart its production activities because its backup power system did not work, the resulting loss of profit is normally not considered an indemnifiable consequence.

Therefore, the servicing and maintenance of the backup power system play a major role. If the company has responsibilities towards third parties requiring undisturbed operations, any interruption in production could give rise to liability for damages.

If you are responsible for the maintenance and testing of your company’s backup power system, make sure that:

  • those in charge of the system’s maintenance and test runs have been trained and authorised by the system’s manufacturer or importer;
  • monthly and annual maintenance has been duly performed in line with the manufacturer’s or importer’s instructions;
  • the maintenance programme includes a test run of the backup power machine, at full load and up to the machine’s normal running temperature, in accordance with the instructions;
  • the system’s maintenance programme includes the testing of its automation by simulating a real power cut, at least on an annual basis, if not more regularly;
  • possible malfunctions or defects, as well as their repair, are documented;
  • and all of the above measures are documented in a maintenance manual.

Anna-Maija Nordling