Project Portable – Low Voltage Fault Passage Indicators (Portable – FPI) is an innovative project to develop portable fault passage indicators that can be used on the low voltage underground network. The equipment will be designed to be used by DNO operational staff to help locate faults on complex radial networks by measuring fault current flow in spurs.
This has the potential to enable more efficient fault locating activities and therefore provide better service for customers. This project will last fifteen months. A previous NIA project, Low Voltage – Underground Fault Location Technologies (LV-UFLT) NIA_SSEN_0037, proved the concept of this innovation.
Benefits
Base Cost - Method Costs over 5 years (Based on 15% Success Rate)
Benefits/Savings because of CI/CML benefits, reduced excavations leading to quicker repairs due to fault location improvements and avoided costs of LV repairs due to
Prevented faults: £1,060,762
Method Cost = £934,918
Base Case = £1,995,680
Base Cost (£1,995,680) – Method Cost (£934,918) = Total Saving of £1,060,762
Learnings
Outcomes
The project has successfully created a step-by-step workflow process for using Portable LV- FPI technologies which brings about improvements in finding the location of LV underground faults.
Positive engagement from operational teams was achieved as they were included in developing the fault-finding workflow process, using the two new types of technology, via hands-on experience on a test network where diverse types of underground LV faults could be created. The time spent with the diverse types of fault-finding technologies in a safe and controlled environment, allowed an understanding of the equipment and the best way it could be used.
Through the rigorous trialling within the test network and the subsequent field trials, FPI methods of LV underground fault finding has been very promising. The FPI technology has been successful in narrowing down the search area; if there are several network circuit spurs the FPI kit has the potential to identify the single circuit with the fault. Engineers trialling the FPI’s deemed this to be the best use case scenario.
Through field trials of the fault passage indicator’s fault location detection equipment, it has been possible to confirm that it is a suitable method for LV underground cable fault location. Previously, TDR’s (Time Domain Reflectometry) were used to locate faults on a network, however LV FPI fills a specific niche where it allows engineers to strategically manipulate fault locators in a reduced time.
Lessons Learnt
Spending quality time initially developing a step-by-step workflow process to investigate LV faults via both the acoustic and FPI technologies with the help of the Operational Teams in a workshop environment has had positive results. The early involvement of the Operational Teams and incorporating their suggestions, has made a significant difference to generating and then maintaining momentum for the onward field trial element.
Maintaining an elevated level of engagement with the Operational Teams when developing the step-by-step workflow process has meant continued feedback from fault investigations on the actual network. This has allowed us to ensure the process for using fault passage indicator technology to locate underground LV faults is suitable for a range of physical terrains and network configurations. The other benefit in this continued field interaction has been the ability to widen the types of faults that the equipment can be used to detect.
As the operational staff are field based, the fault-finding workflows and means by which to record comments have been made available on smartphones. Having the capability to capture data from the field trials has been crucial and allowed us to report back to all involved in the project, at all levels. This data will also support the final assessment of fault passage indicators for LV fault finding equipment used for the project.
