# Microgrid utility-return qualification Canonical URL: https://eloragrid.ai/symbols/microgrid-utility-return-qualification Publisher: Elora Grid Updated: 2026-11-03 Lookup label: MUQ Drawing use: Schematic Reference families: Manufacturer Representation: Functional block Installation focus: microgrids Input: Utility voltage and health Output: Qualified utility-available state Qualifies the utility restoration condition before enabling the assigned reconnect process. ## In plain English ### What this block does Qualifies the utility restoration condition before enabling the assigned reconnect process. ### A simple example In a microgrid serving a switchroom and industrial loads, the controller can move between grid-connected and islanded operating states only through its defined transition logic. Each state needs identifiable source roles and feedback. For this reference, the drawing identifies “Utility voltage and health” at the input and “Qualified utility-available state” at the output. Availability is distinct from synchronism. ### What the drawings help you do Start at the named input: Utility voltage and health. Identify its source device or document and the state represented on the drawing. Follow the named output: Qualified utility-available state. Cross-reference its destination and separate the command from confirmation that the equipment responded. ### Terms - Input: Utility voltage and health - Output: Qualified utility-available state - Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections. Concept diagram: Utility voltage and health → MUQ → Qualified utility-available state A reading guide. The entry's original illustration and input/output facts describe this application. - [Microgrid operating modes and transitions management](https://productinfo.se.com/emol_functional_specifications/doca0371_emol_functionalspecifications/EN/DOCA0371_EMOL_Functional_Specifications_DD00894746.xml/%24/EMOL_OperatingModesandTransitionsManagement_DD00895904) ## What it represents Qualifies the utility restoration condition before enabling the assigned reconnect process. A microgrid operating-mode function coordinates how local sources and loads relate to the utility connection. The selected mode, the measured electrical condition and the actual switching configuration can differ during a transition. In a microgrid serving a switchroom and industrial loads, the controller can move between grid-connected and islanded operating states only through its defined transition logic. Each state needs identifiable source roles and feedback. For this reference, the drawing identifies “Utility voltage and health” at the input and “Qualified utility-available state” at the output. Availability is distinct from synchronism. Show the requested mode, entry conditions, completion feedback and failure indication. These functional blocks explain control responsibilities and do not specify a ready-to-use operating sequence or grid-connection approval. 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 voltage and health. Identify its source device or document and the state represented on the drawing. - Follow the named output: Qualified utility-available state. Cross-reference its destination and separate the command from confirmation that the equipment responded. - Availability is distinct from synchronism. - Show the requested mode, entry conditions, completion feedback and failure indication. These functional blocks explain control responsibilities and do not specify a ready-to-use operating sequence or grid-connection approval. ## Information to show or reference - Label the source and connection reference for utility voltage and health. - Identify the destination and defined state of qualified utility-available state. - Record the equipment or control-document revision supporting this functional block. - Check this application limit in the project design: Availability is distinct from synchronism. ## Important distinction Availability is distinct from synchronism. 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: Microgrids - Input / boundary: Utility voltage and health - Output / connection: Qualified utility-available state - Lookup label: MUQ is a library lookup label, not a standard device designation. ## Public references - [Microgrid operating modes and transitions management](https://productinfo.se.com/emol_functional_specifications/doca0371_emol_functionalspecifications/EN/DOCA0371_EMOL_Functional_Specifications_DD00894746.xml/%24/EMOL_OperatingModesandTransitionsManagement_DD00895904) — Schneider Electric. Public technical context for microgrid operating-mode controls. Grid-connected and island modes, transitions, topology and authority. 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.