The utilization category specifies the nominal electrical performance of the contactor referred to a specific type of load. In the IEC / EN60947-4-1 standard, for each utilization category, the test conditions to which the contactor must be subjected to verify its operational effectiveness are prescribed. The most common utilisation categories for contactors are:

  • AC-1 Non-inductive or slightly inductive loads (in practice resistance control)
  • AC-3 Motor control

See the complete list at the bottom.

For example, if a manufacturer declares that a contactor has an AC-3 rated current of 9A at 400V means that this contactor can control motors with a
maximum rated current of 9A at 400V. The standard requires a long series of tests to confirm the conformity of the product to the control of such motors.

  • AC-1 Non-inductive or slightly inductive loads; resistance furnaces
  • AC-2 Slip-ring motors: starting, switching off
  • AC-3 Squirrel-cage motors: starting, switching off motors during running
  • AC-4 Squirrel-cage motors: starting, plugging, inching
  • AC-5a Switching of electric discharge lamp controls
  • AC-5b Switching of incandescent lamps
  • AC-6a Switching of transformers
  • AC-6b Switching of capacitor banks
  • AC-8a Hermetic refrigerant compresso motor control with manual resetting of overload releases
  • AC-8b Hermetic refrigerant compressor motor control with automatic resetting of overload releases


Other information on this topic

Visit the website page dedicated to contactors.

Check out our video tutorials BF series contactors accessories.