IEEE C57.21:2021

Revision Standard - Active.
All liquid-immersed or dry-type, single-phase or three-phase, outdoor or indoor shunt reactors rated over 500 kVA are covered. Terminology and general requirements are stated, and the basis for rating shunt reactors is set forth. Routine, design, and other tests are described, and methods for performing them are given. Losses and impedance, temperature rise, dielectric tests, and insulation levels are covered. Construction requirements for liquid-immersed reactors and construction and installation requirements for dry-type reactors are presented. This standard also covers thyristor-controlled shunt reactors used in static var compensators.

This standard applies to all oil-immersed or dry-type, single-phase or three-phase, outdoor or indoor shunt reactors rated over 500 kVA. This standard also applies to thyristor-controlled shunt reactors used in static var compensators (SVCs). This standard does not apply to other devices such as the following: a) Shunt reactors, 500 kVA and smaller b) Current-limiting reactors (see IEEE Std C57.16(TM)-2011) c) Arc-suppression coils d) Neutral-grounding devices (see IEEE Std 32(TM)-1972) e) Saturable reactors f) Line-resonant reactors g) Filter reactors
This standard specifies the requirements, terminology, and test code for liquid-immersed and dry-type shunt reactors rated over 500 kVA and for thyristor-controlled shunt reactors used in SVCs.