Power distribution companies rely on miles of aging underground cables to distribute electricity with no cost-effective way of telling which are in danger of failing. One of the problems that can arise in these cables is the failure of current carrying concentric neutrals that wrap around the central conductor. The goal of this project is to test for concentric neutral failure without having to power down the cable.
Un-damaged cables produce a radially symmetric magnetic field when fully powered. Asymmetry in the magnetic field is indicative of one or more failed concentric neutrals. This device is deployed onto a powered cable via hot-sticks, and clamps on for the duration of the test. Two carts move around the cable, and four anisotropic-magnetoresistive sensors on board the cart collect data on the magnetic field produced by the cable. The data is sent through radio to a host computer. This non-intrusive way of testing is a fast and safe alternative to current testing methods.