This Specification describes the functional and performance requirements for the protection of 400 kV, 275 kV and 132 kV oil-immersed series reactors constructed in accordance with IEC 76 or equivalent.

The detailed requirements for back-up protection for series reactors are specified in NGTS 3.6.7 Back-up Protection.

The requirements for devices for mechanical protection including gas and oil actuated relays, and winding temperature instruments are specified in NGTS 2.3 Transformers.

The requirements for the trip relay resetting scheme are specified in NGTS 3.6.15 Trip Relays and Trip Relay Resetting.