# Mechanism pump-start control Canonical URL: https://eloragrid.ai/symbols/mechanism-pump-start-control Publisher: Elora Grid Updated: 2026-11-03 Lookup label: MPC Drawing use: Schematic Reference families: Manufacturer Representation: Functional block Installation focus: switchgear Input: Pressure-maintenance demand Output: Pump start request Requests operation of the mechanism's pressure-maintaining pump according to its defined demand contact. ## In plain English ### What this block does Requests operation of the mechanism's pressure-maintaining pump according to its defined demand contact. ### 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 “Pressure-maintenance demand” at the input and “Pump start request” at the output. The hydraulic circuit is documented separately. ### What the drawings help you do Start at the named input: Pressure-maintenance demand. Identify its source device or document and the state represented on the drawing. Follow the named output: Pump start request. Cross-reference its destination and separate the command from confirmation that the equipment responded. ### Terms - Input: Pressure-maintenance demand - Output: Pump start request - Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections. Concept diagram: Pressure-maintenance demand → MPC → Pump start request A reading guide. The entry's original illustration and input/output facts describe this application. - [Masterclad medium-voltage switchgear: circuit-breaker section interlocks](https://productinfo.se.com/masterclad_mv_switchgear_ib/6055-30-masterclad-15kv-mv-switchgear-ib/English/6055-30%20Masterclad%20MV%20Switchgear%20Indoor%20%28bookmap%29_DD00646805.xml/%24/Section6-CircuitBreakerSectionInter-58DD6EC7) ## What it represents Requests operation of the mechanism's pressure-maintaining pump according to its defined demand contact. 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 “Pressure-maintenance demand” at the input and “Pump start request” at the output. The hydraulic circuit is documented separately. 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: Pressure-maintenance demand. Identify its source device or document and the state represented on the drawing. - Follow the named output: Pump start request. Cross-reference its destination and separate the command from confirmation that the equipment responded. - The hydraulic circuit is documented separately. - 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 pressure-maintenance demand. - Identify the destination and defined state of pump start request. - Record the equipment or control-document revision supporting this functional block. - Check this application limit in the project design: The hydraulic circuit is documented separately. ## Important distinction The hydraulic circuit is documented separately. 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. ## Facts - Representation: Functional block - Installation focus: Switchgear - Input / boundary: Pressure-maintenance demand - Output / connection: Pump start request - Lookup label: MPC is a library lookup label, not a standard device designation. ## Public references - [Masterclad medium-voltage switchgear: circuit-breaker section interlocks](https://productinfo.se.com/masterclad_mv_switchgear_ib/6055-30-masterclad-15kv-mv-switchgear-ib/English/6055-30%20Masterclad%20MV%20Switchgear%20Indoor%20%28bookmap%29_DD00646805.xml/%24/Section6-CircuitBreakerSectionInter-58DD6EC7) — Schneider Electric. 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. ## Graphic scope Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.