In EPN there far fewer ASLs installed than in SPN. Therefore there is an opportunity to install the Fuse Savers on a “clean” feeder that does not have reclosers and ASLs on it already. Through the process described above a particular feeder was identified.

Feeder Shepherd and Dog T off Langham Primary suffered 26 faults last year and 12 short interruptions. 74% of CIs and 90% of CMLs on the feeder were caused by wind & gale, lightning, and trees. The feeder also has 14 spurs with 404 customers on these spurs. The feeder has 1161 customers in total. Last year the feeder had 0.16 CIs and 0.56 CMLs. The feeder has a total of 35km of overhead line. 18km (52%) of the feeder’s overhead line is on spurs.

The feeder also has 147 worst served customers and currently there are no ASLs on the entire feeder.

SPN Analysis

SPN already has a high penetration of ASLs on the network which have been installed over many years. The trial objective here is to install Fuse Savers in a “busy” environment to see how the devices perform alongside a number of different types of reclosers and several ASLs. It is also important to see if the devices can operate in an identical fashion to the existing ASL as well how the devices grade with the existing protection schemes on the feeders.

In SPN, Cranleigh Primary has been selected to implement a number of Fuse Savers in a variety of conditions. Placing Fuse Savers on more than one feeder on one primary, to see how the Fuse Savers work with ASLs and reclosers and the device performs on two phase spurs.

Cranleigh Primary currently has 4 feeders in the worst 20 performing feeders. The primary also has 177 worst served customers. The primary also had 134 short interruptions in the last 5 years (3rd worst in SPN) and 216 faults (2nd worst in SPN) in the last 5 years.

The trial on Cranleigh Primary will be to replace 18 ASLs due for replacement on several feeders off Cranleigh Primary. The benefit of the process is to test whether the devices can fit where ASLs have been installed and therefore be a like-for-like replacement. The customer benefit of installing the Fuse Saver is that the customers on the feeder will retain the current level of protection but without the irritation of short interruptions that occur due to reclosers operating to activate the ASL.

Cranleigh Primary currently has 4 feeders in the worst 20 performing feeders. The primary also has 177 worst served customers. The primary also had 134 short interruptions in the last 5 years (3rd worst in SPN) and 216 faults (2nd worst in SPN) in the last 5 years.

The trial on Cranleigh Primary will be to replace 18 ASLs due for replacement on several feeders off Cranleigh Primary. The benefit of the process is to test whether the devices can fit where ASLs have been installed and therefore be a like-for-like replacement. The customer benefit of installing the Fuse Saver is that the customers on the feeder will retain the current level of protection but without the irritation of short interruptions that occur due to reclosers operating to activate the ASL.

Benefits