Using a series reactor is one method that can help to lower the current when starting up a motor. Either iron or air core reactors can be used during startup. If an air core is used for the series reactor, then a very efficient and reliable soft starter can be designed, which is more suitable for high MW ratings of synchronous/induction motors at MV levels. All of our reactors are designed with taps.

Using a reactor during startup always reduces motor accelerating torque. Unlike with an autotransformer, voltage reduction in the reactor is not fixed, but rather varies with the current. Since this current is determined by total circuit impedance, motor voltage during acceleration depends upon the relative reactor and motor impedances.

General Options for RVMS Panels

• Instead of an incoming vacuum contactor (IVC), a vacuum circuit breaker (CB) can be used
• If a vacuum CB is used, no need to use MV fuses
• Power factor correction capacitors
• Incoming / outgoing surge arresters
• Voltage transformers