TfGM - Floating Earth Package

The floating Earth package of works covers the City Centre (Metrolink 1CC) and the Bury and Altrincham lines. City Centre Metrolink 1CC was constructed in the early 1990s and the traction return system utilised a diode-earthed negative arrangement and stray current collector mats to collect and guide any stray current back to the traction substation negative busbar. The diodes also provided a low impedance return path for fault current to flow from the earth to negative and therefore operate the electrical protection should a fault occur between the OLE and earth. It was therefore not considered necessary to bond any metallic assets or structures at the time of construction. The purpose of…