The electricity supply to customers in the geographic area between Burwell and Bottisham has been very poor for some time. First of all, Eastern Electricity apologises to local residents for the inconvenience and distress resulting from the frequent supply interruptions. These have been due to faults on the 11,000 volt distribution circuit feeding a part of Burwell, Reach, Swaffham Prior, Swaffharn Bulbeck, Lode and Bottisham from a primary substation in Burwell. The supply network is duplicated at higher voltages, i.e. a single fault does not result in a loss of supply to customers. Although it is not possible to duplicate circuits at 11,000 volts, customers are switched on to alternative circuits once we have isolated the faulty section. The main causes of these faults have been weather related (lightning, gale, etc.) and the deterioration of various overhead line components.

Eastern Electricity will implement a programme to improve supply reliability to customers on this circuit. The 11,000 volt spur line to Reach was extensively rebuilt during the summer and we now plan to refurbish or rebuild the overhead circuit between Burwell and Bottisham, including the remaining spur connections. We also propose to establish connecting links with adjacent 11,000 volt circuits in Newmarket, Swaffham Prior, Lode and Quy. A contractor (ESB International) has been appointed to carry out the overhead line work during the first quarter of 1998. The circuit links involve negotiations with third parties but it is hoped to install most of them at the same time. The work will involve access to our existing high voltage poles and lines and vehicles moving around the area. Unfortunately, in order for the work to be carried out safely, there will need to be short supply interruptions to some customers while work is done. All the affected customers will be notified in writing a week before and we will ndeavour to reduce the periods without supply to the very minimum.

This work will greatly improve the supply reliability but customers may sometimes experience brief interruptions of supply due to the operation of automatic high voltage switches, preventing transient faults from causing a permanent loss of supply. Examples of this type of fault are wind borne debris (twigs, branches, straw, etc.), lightning, and impact by large birds (we install bird flight deflectors where geese and swans are known to take off and land).

In dealing with these incidents, the switch will open very quickly when a fault occurs, limiting damage, then reclose automatically after a brief period to restore supply. If the fault is still there, for example when a branch remains on the line, the switch will lock open and the fault will need to be located and repaired by our operational staff.