HFSR & FCMA Starters

HFSR & FCMA are 2 different types of motor starters that are widely utilized in industrial applications.

HFSR (High Full-load Slip Ratio) starter

  • The HFSR (High Full-load Slip Ratio) starter is designed for starting high-inertia loads as fans, pumps, and compressors.
  • It is intended to compensate for the high starting torque needs of these loads by enabling the motor to operate at a slip speed greater than its synchronous speed throughout the starting phase.
  • The slip speed is difference between the motor rotor’s actual speed and the synchronous speed (the speed of the rotating magnetic field).
  • In an HFSR starter, the slip speed is specifically increased to generate the torque required to start the load.
  • HFSR starters often employ wound-rotor induction motors with the external resistors (or) additional rotor windings to obtain the appropriate slip speed during start-up.
  • These resistors (or) additional windings are progressively bypassed as motor accelerates, enabling it to reach full power.

FCMA (Flux Compensated Magnetic Amplifier) Starter

  • FCMA starter is a kind of motor starter that controls the starting and halting of induction motors.
  • It uses a flux compensated magnetic amplifier, that’s an electrical device that controls the magnetic field in the motor’s stator windings.
  • FCMA starters are well-known for their soft start and stop characteristics. They gently raise or reduce the voltage provided to the motor during start-up or shutdown, decreasing mechanical & electrical stress on the motor & the linked load.
  • FCMA starters’ steady voltage ramp-up and ramp-down help prevent excessive current surges & mechanical shocks caused by abrupt starts and stops.
  • FCMA starters are especially beneficial in applications that demand smooth acceleration and deceleration, such as conveyors, pumps, and motor-driven machinery.

Difference Between HFSR and FCMA Starters

The key difference between HFSR & FCMA starters is their working principles and the types of motors they are designed.

HFSR Starters FCMA Starters
HFSR starters are intended to manage high-inertia loads by allowing the motor to operate at a greater slip speed while starting. FCMA starters, on the other hand, use electronic control to give soft-start and soft-stop capabilities, resulting in smooth acceleration and deceleration for a wide range of motor applications.