FAQs

Why use an adjustable speed drive?

An adjustable speed drive (ASD) regulates motor speed to match actual load requirements, which can lead to substantial energy savings, often up to 70% in variable torque applications such as fans and pumps.

Beyond energy efficiency, ASDs provide improved process control, motor overload protection, unlimited starting capability, and reduced mechanical and electrical stress. These benefits can help extend motor life and lower maintenance requirements in AC motor systems.

What is an adjustable speed drive?

An adjustable speed drive (ASD), also referred to as a variable speed drive (VSD) or variable frequency drive (VFD), is an electronic device that controls the speed and torque of an AC motor by varying the frequency and voltage of the electrical power supplied to it. This enables precise motor control, improved process performance, and potential energy savings in a wide range of industrial applications.

An ASD converts incoming AC power to DC through rectification, then inverts it back to a controlled three-phase AC output at variable frequency and voltage. This output allows the connected motor to operate at the desired speed. Adjustable speed drives are commonly applied in pumps, fans, compressors, conveyors, and other variable-torque systems.

Where is the AS3 manufactured?

Manufacturing locations vary by voltage rating, frame size, and configuration:

  • 230 V:
    • Frames 2004–2037: Indonesia
    • All other sizes: China
  • 460 V:
    • Frames 4004–4075: Indonesia
    • All other sizes: India
  • 600 V: India
  • IP55 versions: China
  • AS3P: United States (Houston, Texas)

Does the AS3 work on single-phase power?

Yes. The AS3 can operate on single-phase input power; however, the drive must be de-rated. As a general rule of thumb, select a drive with approximately double the motor horsepower rating. When operating on single-phase power, the RF/EMI filter must also be removed.

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