Earthing-switch position discrepancy interface

What it represents

Reports a defined conflict or missing completion in earthing-switch position feedback. Disconnector and earthing references identify different mechanical constructions and connection duties within a yard. The primary diagram shows which conductors are joined or earthed; the equipment drawing explains how its contacts and supports move.

In a switchyard bay, a bus selector can use a different physical construction from a line disconnector. Each device still needs an identified operating mechanism, position indication and interlocking interface. For this reference, the drawing identifies “Earthing position contacts” at the input and “Position discrepancy alarm” at the output. Invalid status must remain distinguishable from open status.

The construction name does not establish load-breaking capability, short-circuit making duty or operating permission. Verify these properties in the selected equipment data and the station interlocking scheme. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation.

How to read it

• Start at the named input: Earthing position contacts. Identify its source device or document and the state represented on the drawing.
• Follow the named output: Position discrepancy alarm. Cross-reference its destination and separate the command from confirmation that the equipment responded.
• Invalid status must remain distinguishable from open status.
• The construction name does not establish load-breaking capability, short-circuit making duty or operating permission. Verify these properties in the selected equipment data and the station interlocking scheme.

Information to show or reference

• Label the source and connection reference for earthing position contacts.
• Identify the destination and defined state of position discrepancy alarm.
• Record the equipment or control-document revision supporting this functional block.
• Check this application limit in the project design: Invalid status must remain distinguishable from open status.

Sources you can follow

These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.

About this graphic

This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.

SVG and DXF downloads contain this original artwork. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.