Applies to the connection of data processing equipment to the electrical power installation of buildings, where the data processing equipment: - has earth leakage current exceeding the limit specified in IEC 60950 and complies with IEC 60083; - complies with the requirements of IEC 60950 which cover leakage current. May also be applied where installations, other than data processing, such as those for industrial control and telecommunication equipment carry high leakage current due to radio-frequency interference suppression filtering requirements.