Feature

VSDs vs soft starters: A guide to choosing the right efficiency equipment

Approximately eight billion electric motors are in operation in Europe, consuming nearly half of all the continent’s electricity. Variable speed drives (VSDs) and soft starters provide ways to reduce the energy consumption of a motor, by providing operators with control over their power. But which is the most appropriate choice?

04/01/2022 17:00:46

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What’s a soft starter?

Solid-state soft starters use semiconductor devices to reduce temporarily the terminal voltage of the motor. This provides control of the
motor current, to reduce inrush and limit shaft torque. Soft starters allow the motor to start the load more gradually, by limiting the voltage to the
motor and providing a reduced torque.

In addition to reducing energy consumption, a reduced-voltage soft starter helps protect the motor and connected equipment from damage,
by controlling the terminal voltage. This limits the initial inrush of electrical current and reduces the mechanical shock associated with motor start-up. Soft starters are also
capable of providing a gradual ramp to stop, where a sudden halt may create problems in the connected equipment.

What’s a VSD?

Read the full article in DPA's January issue

Written By Sophia Bell

Sophia Bell is the Group Editor of DPA, Connectivity, and PBSI. She joined the team in 2020 as Assistant Editor after achieving a First-Class Honours BA in English Literature and Film Studies from the University of East Anglia. In her current role, she leads the editorial strategy, driving digital growth and ensuring each title continues to deliver trusted, relevant insight for engineering and manufacturing professionals.