Functional block · SDR

Semi-pantograph disconnector reference

Functional block · Switchyards

An independently authored application reference. The drawing shows the named function or circuit relationship; use the project legend and selected equipment documentation for its drafting form and connections.

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In plain English

What this block does

Identifies the documented semi-pantograph construction at its assigned yard connection.

A simple example

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 “Bay primary terminal” at the input and “Semi-pantograph bus connection” at the output. Its operating envelope differs from other constructions.

Bay primary terminalSDRSemi-pantograph bus connection
A reading guide. The entry's original illustration and input/output facts describe this application.

What the drawings help you do

Start at the named input: Bay primary terminal. Identify its source device or document and the state represented on the drawing. Follow the named output: Semi-pantograph bus connection. Cross-reference its destination and separate the command from confirmation that the equipment responded.

Input
Bay primary terminal
Output
Semi-pantograph bus connection
Application reference
An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Read the source: Disconnectors and earthing switches

Schematic · SDRSemi-pantograph disconnector reference: original educational illustration
Original educational illustrationSee source and graphic notes

What it represents

Identifies the documented semi-pantograph construction at its assigned yard connection. 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 “Bay primary terminal” at the input and “Semi-pantograph bus connection” at the output. Its operating envelope differs from other constructions.

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: Bay primary terminal. Identify its source device or document and the state represented on the drawing.
  • Follow the named output: Semi-pantograph bus connection. Cross-reference its destination and separate the command from confirmation that the equipment responded.
  • Its operating envelope differs from other constructions.
  • 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 bay primary terminal.
  • Identify the destination and defined state of semi-pantograph bus connection.
  • Record the equipment or control-document revision supporting this functional block.
  • Check this application limit in the project design: Its operating envelope differs from other constructions.

A distinction that matters

Its operating envelope differs from other constructions. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.

Sources you can follow

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

Disconnectors and earthing switches

Public technical context for disconnector and earthing applications. Disconnector construction, earthing switches and operating mechanisms. The application text and educational graphic are independently authored; the publisher does not certify this representation.

Siemens Energy · Public reference checked 3 November 2026 · Link only

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.

Entry JSON · Entry Markdown · Last editorial update: 3 November 2026

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