Rotary Cam Switch - FAQ's

Rotary Cam Switch >> FAQ's

• What is a CAM Switch?

  • A CAM switch is one that employs the rotation of a CAM shaft to operate a number of switching elements simultaneously.

• What are the standards governing CAM Switches?

  • The standards governing CAM switches are :
    • IEC 947-3 and IEC 947-5-1 (Control application)
    • IS 13947
    • EN 60947

• What is a utilization category?

  • Utilization category defines the intended application of the switching device. Although the actual utilization differs for each type of switching device, they are all characterized by one or more of the following parameters:
    • Values of making and breaking currents expressed as multiples of the rated operational voltage
    • Values of the voltage as multiples of rated operational voltage
    • Values of power factor

• Name the utilization categories applicable to CAM switches?

  • Utilization categories applicable to CAM switches are:
    • AC-21A - purely resistively loads
    • AC-22A - combination of resistive and inductive loads
    • AC-23A - starting and switching off of inductive loads
    • AC-3 - starting and switching off during running of a Squirrel Cage Induction Motor (SCIM)

• Can customers get any additional features in GT?

  • Customer can ask for additional features like inclusion of auxiliary NO/NC, extended terminals, MS back plate etc.

• What is a make before break switch?

  • If in a pair of auxiliary contacts (1NO + 1NC), the normally open contact closes before the normally closed contact has opened; we refer to the pair as "make-before-break" contacts.

• Can GT CAM switches be used for DC applications?

  • Yes, GT CAM switches can be used for DC applications based on a rating chart which is available on request.

• How is the life of a CAM switch determined?

  • The life of a CAM switch is determined based on two parameters:
    • Mechanical life
    • Electrical life

    GT CAM switches possess a mechanical life of one million operations and an electrical life of a few thousand operations. To achieve the stipulated working limits, due diligence must be exercised in choosing an appropriate current rating based on the load conditions and other environmental factors.

• Does the smooth working of the knob determine the quality of a CAM switch?

  • No. In fact a slightly harder knob mechanism ensures proper opening and closing of contacts.

• What are the various mountings available in a CAM switch?

  • • Panel mounting without anchorage plate
    • Panel mounting with anchorage plate
    • Central fixing
    • Base mounting with direct handle
    • Base mounting with panel handle
    • Switch mounted inside an enclosure