This standard applies to series-connected dry-type air-core single-phase and three-phase outdoor or indoor reactors of distribution and transmission voltage class that are connected in the power system to control power flow under steadystate conditions and/or limit fault current under short-circuit conditions. Dry-type air-core reactors covered by this standard are self-cooled by natural air convection.With some restrictions@ this standard is applicable to filter reactors@ shunt capacitor reactors (used with shunt capacitor banks)@ and discharge current-limiting reactors (used with series capacitor banks). Annexes A@ B@ and C are included to provide guidance.This standard does not apply to devices such asa) Shunt reactors (see IEEE Std C57.21-1990@ IEEE Standard Requirements@ Terminology@ and Test Code for Shunt Reactors Rated Over 500 kVA)@b) Arc suppression coils@c) Neutral grounding devices [see IEEE Std 32-1972 (Reaff 1990)@ IEEE Standard Requirements@ Terminology@ and Test Procedures for Neutral Grounding Devices]@d) Line resonant reactors@e) High-Voltage direct current (HVDC) smoothing reactors@f) Forced cooled reactors@ andg) Line traps and radio interference (RI) filter reactors (ANSI C93.3-1995).