What is the function of a soft starter, and how does it differ from a variable-frequency drive?

• A. A soft starter gradually increases voltage to start a motor; a VFD varies frequency and voltage to control speed.
• B. A soft starter alters motor speed by changing frequency; a VFD only limits inrush.
• C. A soft starter blocks all voltage until full speed; a VFD provides continuous torque at all times.
• D. A soft starter converts DC to AC for controlled start; a VFD converts AC to DC.

Answer: (A)