Drives & Starters

What are Drives & Starters?

download (2)A variable frequency drive (VFD) refers to AC drives only and a variable speed drive (VSD) refers to either AC Drives or DC Drives. VFDs vary the speed of an AC motor by varying the frequency to the motor. VSDs referring to DC motors vary the speed by varying the voltage to the motor.

A Soft Starter can do similar functions when it comes to ramp up or down a motor. The main difference between the two is that a VFD can vary the speed of a motor while a soft starter only controls the starting and stopping of that motor.

Drives and Starters dramatically reduce start up energy, whilst ensuring motor wear is significantly reduced. Predominately found in 3-phase applications, a drive or starter will significantly reduce your overall running costs.

Why Test Drives & Starters?

Without preventative maintenance, the probability of VFD/VSD failure increases drastically. The most common failures are due to component aging or operational conditions, such as varying ambient temperature, high humidity, excessive and heavy loads.

It is essential that these key basic maintenance steps are followed to ensure reliability and extended life, these include, but are not limited to:

  • Keeping the drive and its surrounds clean, and free of excessive dust
  • Keeping the drive cool, with sufficient cool airflow
  • Keeping the drive free of moisture, leading to corrosion and/or an unreliable system
  • Keeping the drives connections tight, commonly from vibration and heat


Testing and Inspections

img_01Preventative Electrical Services conducts a thorough inspection and maintenance procedure on all makes and models of drives and starters. A customer who understands the importance of a preventative maintenance plan will help increase the life of their equipment.

Some of the key maintenance tasks includes:

  • Visual inspection of the drive
  • Inspect the environmental conditions and surrounds
  • Inspection of fault log history
  • Electrostatic discharge protected cleaning
  • Inspection of fans and cooling systems
  • Retrieval and storage of parameters
  • Inspection of safety functions, interlocks and start-ups
  • Functional and basic measurement tests
  • Spare part checks