Motor Circuits & Invertors

Electrical Multiskill E5: This module introduces candidates to motor starter circuits where soft starting devices are used, and systems where motor speed is controlled and varied using an Inverter. On successful completion of this module candidates will be able to:

  • understand the principles of two speed motors and star-delta motor starting techniques
  • use the correct methods for connecting Inverters or Soft Starters into circuits and to install them in control panels
  • recognise the devices as Inverters or Soft Starters, understand their operation and recognise normal operation and fault conditions
  • use the correct test equipment to diagnose faults on circuits with such equipment connected
  • gain further experience in fault diagnosis particularly on power circuit devices

What you'll learn

The following topics:

  • Two speed motors and motor starting techniques
  • Function and operation of soft starters and invertors
  • The correct methods for connecting invertors or soft starters into circuits
  • How they should be installed in control panels
  • Recognising the devices as invertors or soft starters
  • Understanding their normal operation
  • Recognise abnormal operation and fault conditions
  • Understand the dangers of using a Megger to diagnose faults on circuits
  • Further experience in fault diagnosis, particularly with power electronic devices


Course Objective

On successful completion of this module, trainees will be able to recognise a motor starter and Invertor variable speed drive or soft start configuration and know the correct approach to take in identifying and rectifying faults. They will be able to follow power and control circuit drawings by identifying components and their connection within circuits.

Time frame

3 day course.


Map of IPS Rochester IPS International Northbank House Sir Thomas Longley Road Rochester Kent ME2 4DU

additional information

These modules and bespoke modules may be delivered on site at IPS or at customer premises.

These modules can be used in conjunction with an NVQ programme to support and supplement the practical skills requirements.