Functional block · UICI

Utility incomer connection 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

Identifies the utility-side incoming switching point and its bus interface.

A simple example

In a switchgear lineup with two incomers and a bus tie, the single-line arrangement helps the engineer identify normal supply paths and which loads change source during a transfer. For this reference, the drawing identifies “Utility feeder” at the input and “Utility-to-bus connection” at the output. Connection rules depend on the network agreement.

Utility feederUICIUtility-to-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: Utility feeder. Identify its source device or document and the state represented on the drawing. Follow the named output: Utility-to-bus connection. Cross-reference its destination and separate the command from confirmation that the equipment responded.

Input
Utility feeder
Output
Utility-to-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: SEL-451 protection, automation and bay control

Schematic · UICIUtility incomer connection interface: original educational illustration
Original educational illustrationSee source and graphic notes

What it represents

Identifies the utility-side incoming switching point and its bus interface. A source and bus arrangement shows how incoming supplies and outgoing circuits can be connected. Breaker and tie positions determine which sections are energized and whether sources can become electrically paralleled.

In a switchgear lineup with two incomers and a bus tie, the single-line arrangement helps the engineer identify normal supply paths and which loads change source during a transfer. For this reference, the drawing identifies “Utility feeder” at the input and “Utility-to-bus connection” at the output. Connection rules depend on the network agreement.

Keep normal positions, transfer limits, source independence and protection-zone boundaries visible. An arrangement drawing explains connectivity; the permitted switching sequence needs a separate approved 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: Utility feeder. Identify its source device or document and the state represented on the drawing.
  • Follow the named output: Utility-to-bus connection. Cross-reference its destination and separate the command from confirmation that the equipment responded.
  • Connection rules depend on the network agreement.
  • Keep normal positions, transfer limits, source independence and protection-zone boundaries visible. An arrangement drawing explains connectivity; the permitted switching sequence needs a separate approved scheme.

Information to show or reference

  • Label the source and connection reference for utility feeder.
  • Identify the destination and defined state of utility-to-bus connection.
  • Record the equipment or control-document revision supporting this functional block.
  • Check this application limit in the project design: Connection rules depend on the network agreement.

A distinction that matters

Connection rules depend on the network agreement. 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-451 protection, automation and bay control

Public technical context for switchboard source and bus interfaces. Bus arrangements, breaker control and bay-level coordination. 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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