Functional block · LMEI

Lightning mast earth-grid interface

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 earthing connection associated with the selected lightning-protection mast.

A simple example

In a switchyard arrangement, the earthing references help connect each primary equipment structure and surge-protection device to the correct earth-grid interface. Separate details show actual joints, sizes and installation routes. For this reference, the drawing identifies “Lightning mast earth connection” at the input and “Station earth grid” at the output. Mast location and protection coverage need separate design.

Lightning mast earth connectionLMEIStation earth grid
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: Lightning mast earth connection. Identify its source device or document and the state represented on the drawing. Follow the named output: Station earth grid. Cross-reference its destination and separate the command from confirmation that the equipment responded.

Input
Lightning mast earth connection
Output
Station earth grid
Application reference
An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Read the source: Earthing connections

Schematic · LMEILightning mast earth-grid interface: original educational illustration
Original educational illustrationSee source and graphic notes

What it represents

Identifies the earthing connection associated with the selected lightning-protection mast. Earthing and lightning interfaces identify the connections between equipment metalwork, primary protection devices and the station earthing network. Their electrical purpose differs from their physical conductor route or electrode geometry.

In a switchyard arrangement, the earthing references help connect each primary equipment structure and surge-protection device to the correct earth-grid interface. Separate details show actual joints, sizes and installation routes. For this reference, the drawing identifies “Lightning mast earth connection” at the input and “Station earth grid” at the output. Mast location and protection coverage need separate design.

Name every connected item and the earthing design reference. The illustrative connection does not establish touch or step voltages, conductor sizing, lightning coverage or safe working conditions. 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: Lightning mast earth connection. Identify its source device or document and the state represented on the drawing.
  • Follow the named output: Station earth grid. Cross-reference its destination and separate the command from confirmation that the equipment responded.
  • Mast location and protection coverage need separate design.
  • Name every connected item and the earthing design reference. The illustrative connection does not establish touch or step voltages, conductor sizing, lightning coverage or safe working conditions.

Information to show or reference

  • Label the source and connection reference for lightning mast earth connection.
  • Identify the destination and defined state of station earth grid.
  • Record the equipment or control-document revision supporting this functional block.
  • Check this application limit in the project design: Mast location and protection coverage need separate design.

A distinction that matters

Mast location and protection coverage need separate design. 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.

Earthing connections

Public technical context for switchyard earthing and lightning interfaces. Protective earthing, bonding and earth-electrode interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation.

Schneider Electric, Electrical Installation Guide · Public reference checked 28 October 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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