Functional block · VDRI

Variable-speed drive run-enable interface

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

Carries a permitted run command to the drive control interface.

A simple example

In a switchroom motor-control panel, a ventilation motor can receive an automatic start request while a local selector and the motor protection determine whether the feeder is available. For this reference, the drawing identifies “Run permission” at the input and “Drive enable signal” at the output. Run enable differs from a safety-rated torque-off function.

Run permissionVDRIDrive enable signal
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: Run permission. Identify its source device or document and the state represented on the drawing. Follow the named output: Drive enable signal. Cross-reference its destination and separate the command from confirmation that the equipment responded.

Input
Run permission
Output
Drive enable signal
Application reference
An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Read the source: SEL-710 motor protection and control

Schematic · VDRIVariable-speed drive run-enable interface: original educational illustration
Original educational illustrationSee source and graphic notes

What it represents

Carries a permitted run command to the drive control interface. A motor feeder combines switching, motor protection and an operating command. Starting permission, running feedback and protection trip are different signals even where one relay or controller processes all of them.

In a switchroom motor-control panel, a ventilation motor can receive an automatic start request while a local selector and the motor protection determine whether the feeder is available. For this reference, the drawing identifies “Run permission” at the input and “Drive enable signal” at the output. Run enable differs from a safety-rated torque-off function.

Link the motor tag to its contactor, protective device and process permissives. The control diagram must identify stop priority, feedback and restart philosophy without supplying unverified settings. 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: Run permission. Identify its source device or document and the state represented on the drawing.
  • Follow the named output: Drive enable signal. Cross-reference its destination and separate the command from confirmation that the equipment responded.
  • Run enable differs from a safety-rated torque-off function.
  • Link the motor tag to its contactor, protective device and process permissives. The control diagram must identify stop priority, feedback and restart philosophy without supplying unverified settings.

Information to show or reference

  • Label the source and connection reference for run permission.
  • Identify the destination and defined state of drive enable signal.
  • Record the equipment or control-document revision supporting this functional block.
  • Check this application limit in the project design: Run enable differs from a safety-rated torque-off function.

A distinction that matters

Run enable differs from a safety-rated torque-off function. 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.

SEL-710 motor protection and control

Public technical context for motor-feeder control interfaces. Motor feeder thermal, starting and control functions. The application text and educational graphic are independently authored; the publisher does not certify this representation.

SEL · 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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