A recent project planned to replace four of the seven generators which were beyond economical repair. UK based genset company International Power Generation Ltd (IPG) won the contract to supply the four replacement gensets and replace the controls on the remaining three sets.

Four previously used 1750kW sets with Detroit Diesel engines were obtained from a government building in Livingstone, Scotland. The sets had a history of low usage, with minimal hours on the clock, so they were ideal replacements for the Sierra Leone project.

The sets were serviced and refitted with new DSE synchronising & load sharing control modules.

The sets were configured and tested in the UK as a four-set, automatic, load sharing system with load demand scheme. The load demand scheme allows sets to come on line in a chosen sequence, when load demand reaches predetermined levels. For example, on starting up the system, all four generators will start, synchronise and take the load. Each controller is monitoring the Bus and a priority order has been set by the engineer. If the load is below the chosen level (this can be set to % of genset capacity), the last generator in the priority sequence will begin its shutdown procedure. If the load continues to drop, other gensets will shutdown in order of priority. Conversely, if the load increases, gensets will start, synchronise and share the load, again, according to the priority order.

This type of load demand scheme is used to ensure engines are not run to maximum capacity for long periods of time, reducing engine stress and leading to a longer engine life. Each controller can be set to whatever level is considered acceptable e.g. 50% – Once load on the generator reaches 50% of total capacity, the second generator will come on line and share the load etc. Changes to the load level settings can easily be made via PC and DSE user-friendly Windows® based software. Changes to the priority sequence and other parameter settings can also be made in the same way.

When the system was completed, it was fully tested with a load bank at the IPG workshop prior to shipping. The IPG engineers were delighted with its performance. The system was then delivered to Sierra Leone and installed with great success.