Shunt reactors are intended for parallel connection in a system to compensate for capacitive current, as generated by long, lightly loaded transmission lines or underground cables.

With regard to installation, these devices may be identified as:

• Single phase or three phase
• Cast resin dry type, conventional dry type or oil immersed
• With or without magnetic shield
• For indoor or outdoor installation
• With or without enclosure
• With fixed or variable reactance
• With or without additional loading winding

The absorbed reactive power can be fixed or may be varied by the use of additional devices such as:

• Winding tappings using on load or off load tapchangers or links
• Phase controlled thyristors in Static VAR systems
• Direct current magnetisation of the core.