Modular power tile and method of operating a power distribution system

A modular power tile 50, 54 includes a power input 99, a set of power outputs to loads 90 via solid state power controllers 72, 74, 76 and conducting wires 86, each having an impedance 88. A controller module 92 uses time domain reflectometry to inject a predetermined identifying pattern onto a voltage at the power input 99 and determine impedance characteristics 88 from the reflected incident signal. This operation is performed during routine power supplying operations of the power distribution system and does not inhibit normal operation of the loads 90. The determined impedance characteristics may be transmitted to a maintenance system 60 via a communication interface 106. The maintenance system 60 may determine a present or predicted fault on the conductor 88 and may schedule a maintenance task. The system may be configured for spread spectrum time domain reflectometry. The impedance characteristics may include scattering parameters.