NR NR/SP/ELP/21014 ISSUE 2 PDF

This specification applies to the major items of electrical distribution equipment (switchgear, transformers and cables) in the range 3.3 kV to 66 kV, 50 Hz on A.C. and D.C. Electrified Lines.

This specification does not apply in cases where equipment is removed from site for major refurbishment, modification or repair.

Purpose

This specification states the requirements for on-site voltage testing (pressure testing) of major items of electrical distribution equipment, including cables, in the range 3.3 kV to 66 kV, 50 Hz, on A.C. and D.C. Electrified Lines when the performance of insulation has been affected by refurbishment, modification, repair or relocation. The specification provides guidance on the selection of test voltage values and durations applicable to the equipment as it ages.

The voltage testing is to establish whether the electrical insulation properties of the equipment are acceptable for return to service.