Magnetic field levels near underground distribution systems

This paper reports on measurements taken in and around installations forming part of underground distribution systems with the aim to identify nearby magnetic fields levels. In area accessible to the public, the highest magnetic field level measured is about12 µT on top of a single-phase transformer. For the utility workers, the maximum value recorded is around 80 µT measured inside a cable vault. Both these levels are significantly lower than ICNIRP recommended limits but they have not been measured at rated currents.