Overhead line fault current indicators-are they cost effective?

2.7 million customers in the UK are supplied from 11 kV overhead networks. On average, they lose their supply for about 4 hours each year compared with about 30 minutes for their counterparts in urban areas fed from underground cables. As these are average values, many customers living in rural areas will suffer from interruptions of much longer duration. Accurate and reliable indication of the fault position by fault current indicators will give quicker and simpler fault location, more rapid restoration of supply to affected customers, more efficient use of operational staff and reduced wear and tear on the system. The author looks at fault current indicators and also presents an economic assessment of their feasibility