Project background

Pharos Generator Services (PGS) was tasked with the overhaul of two Dorman SET 12 engine generators for the UK’s largest telecoms company. The upcycling and recommissioning of older equipment, instead of buying new, generated both financial and environmental savings for BT and EE.


Project summary

PGS has extensive experience of the overhaul of generators. The project assigned by BT/EE included a full top- and bottom-end overhaul of previously installed Dorman SET 12 engine generators that were manufactured in 1989. During the rebuild, we had to reconstruct each unit from scratch to enable a full investigation of parts that were 10–15 years old. The process included the procurement of parts, salvaging and reverse engineering where needed.

Once the rebuild was complete, PGS engineers carried out a factory acceptance test and load banking up to the required spec requested by BT/EE. Once passed, each unit was recommissioned and returned to service.


Meeting challenges

The initial challenge faced was the overhaul of units that were between 10 and 15 years old. Some units required a full rebuild from scratch, which involved the procurement of parts that were difficult to source. It was necessary to purchase some parts off-the-shelf and the salvaging of others was carried out by our engineers. Some timescale restraints were in place due to the client requiring the units earlier than initially expected. The units also required load banking up to a specification requested by the client.



The benefits of this project were very clear – not only were there environmental savings to be made through the recommissioning of units 10–15 years old but there was an estimated cost saving of around £100,000 per unit for BT/EE. As the assets were in good condition overall, the additional benefits of a full top- and bottom-end overhaul will see them last another 20 years.


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Close up of investigation into 10-15 year old parts
Completed rebuild of the 2x dorman SET 12 engine generator
Internal unit of 2x Dorman SET 12 engine generator