Functional block · HOS

Hydraulic operating-pressure supervision

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

Uses the selected hydraulic mechanism's pressure switch or sensor as a readiness input.

A simple example

In a switchgear panel, a charging motor replenishes the mechanism after an operation. Supervisory contacts let the controller report an incomplete charge or repeated charging demand before an operator requests another operation. For this reference, the drawing identifies “Hydraulic pressure condition” at the input and “Mechanism pressure status” at the output. Thresholds come from the selected operating mechanism.

Hydraulic pressure conditionHOSMechanism pressure status
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: Hydraulic pressure condition. Identify its source device or document and the state represented on the drawing. Follow the named output: Mechanism pressure status. Cross-reference its destination and separate the command from confirmation that the equipment responded.

Input
Hydraulic pressure condition
Output
Mechanism pressure status
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 · HOSHydraulic operating-pressure supervision: original educational illustration
Original educational illustrationSee source and graphic notes

What it represents

Uses the selected hydraulic mechanism's pressure switch or sensor as a readiness input. A stored-energy breaker mechanism has charging, release, indication and supervision functions. Motor supply, stored spring energy and the ability to complete an opening operation are separate drawing concerns.

In a switchgear panel, a charging motor replenishes the mechanism after an operation. Supervisory contacts let the controller report an incomplete charge or repeated charging demand before an operator requests another operation. For this reference, the drawing identifies “Hydraulic pressure condition” at the input and “Mechanism pressure status” at the output. Thresholds come from the selected operating mechanism.

Show the individual contacts and the relevant motor or release circuit. Supply voltage, charging time, operating duty and permissible alarms must follow the chosen mechanism documentation. 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: Hydraulic pressure condition. Identify its source device or document and the state represented on the drawing.
  • Follow the named output: Mechanism pressure status. Cross-reference its destination and separate the command from confirmation that the equipment responded.
  • Thresholds come from the selected operating mechanism.
  • Show the individual contacts and the relevant motor or release circuit. Supply voltage, charging time, operating duty and permissible alarms must follow the chosen mechanism documentation.

Information to show or reference

  • Label the source and connection reference for hydraulic pressure condition.
  • Identify the destination and defined state of mechanism pressure status.
  • Record the equipment or control-document revision supporting this functional block.
  • Check this application limit in the project design: Thresholds come from the selected operating mechanism.

A distinction that matters

Thresholds come from the selected operating mechanism. 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 stored-energy mechanism supervision. 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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