Functional block · TIR

Trip-output interposing relay

Functional block · Switchgear

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

Transfers a protective-relay output to an opening circuit with a different electrical duty.

A simple example

In a switchgear incomer panel, a protection relay requests opening and an auxiliary contact reports the resulting breaker position. A second trip path can have its own supply and wiring so that a single wiring fault does not remove both paths. For this reference, the drawing identifies “Relay trip output” at the input and “Interposing contact” at the output. Contact duty is distinct from relay logic.

Relay trip outputTIRInterposing contact
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: Relay trip output. Identify its source device or document and the state represented on the drawing. Follow the named output: Interposing contact. Cross-reference its destination and separate the command from confirmation that the equipment responded.

Input
Relay trip output
Output
Interposing contact
Application reference
An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Read the source: Masterclad medium-voltage switchgear: circuit-breaker section interlocks

Schematic · TIRTrip-output interposing relay: original educational illustration
Original educational illustrationSee source and graphic notes

What it represents

Transfers a protective-relay output to an opening circuit with a different electrical duty. A trip circuit carries an opening request from a control or protection device to the breaker operating mechanism. The opening command, the coil supply and the evidence that the breaker opened are separate parts of the drawing.

In a switchgear incomer panel, a protection relay requests opening and an auxiliary contact reports the resulting breaker position. A second trip path can have its own supply and wiring so that a single wiring fault does not remove both paths. For this reference, the drawing identifies “Relay trip output” at the input and “Interposing contact” at the output. Contact duty is distinct from relay logic.

Trace the initiating contact, protective fuse, trip coil, return conductor and feedback independently. Identify which elements are shared between redundant paths. The diagram explains the intended command path; coil ratings and terminal numbers come from the selected breaker. 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: Relay trip output. Identify its source device or document and the state represented on the drawing.
  • Follow the named output: Interposing contact. Cross-reference its destination and separate the command from confirmation that the equipment responded.
  • Contact duty is distinct from relay logic.
  • Trace the initiating contact, protective fuse, trip coil, return conductor and feedback independently. Identify which elements are shared between redundant paths. The diagram explains the intended command path; coil ratings and terminal numbers come from the selected breaker.

Information to show or reference

  • Label the source and connection reference for relay trip output.
  • Identify the destination and defined state of interposing contact.
  • Record the equipment or control-document revision supporting this functional block.
  • Check this application limit in the project design: Contact duty is distinct from relay logic.

A distinction that matters

Contact duty is distinct from relay logic. 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.

Masterclad medium-voltage switchgear: circuit-breaker section interlocks

Public technical context for breaker trip circuits. Breaker control, mechanism, position contacts, racking interlocks and test interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation.

Schneider Electric · 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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