# Microgrid unintentional-island response coordinator Canonical URL: https://eloragrid.ai/symbols/microgrid-unintentional-island-response-coordinator Publisher: Elora Grid Updated: 2026-11-03 Lookup label: MURC Drawing use: Schematic Reference families: Manufacturer Representation: Functional block Installation focus: microgrids Input: Utility-loss and topology states Output: Assigned island response Applies the documented control response to an externally initiated loss of utility connection. ## In plain English ### What this block does Applies the documented control response to an externally initiated loss of utility connection. ### 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-loss and circuit arrangement states” at the input and “Assigned island response” at the output. Protection and controller responses require coordination. ### What the drawings help you do Start at the named input: Utility-loss and circuit arrangement states. Identify its source device or document and the state represented on the drawing. Follow the named output: Assigned island response. Cross-reference its destination and separate the command from confirmation that the equipment responded. ### Terms - Input: Utility-loss and topology states - Output: Assigned island response - Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections. Concept diagram: Utility-loss and topology states → MURC → Assigned island response 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 Applies the documented control response to an externally initiated loss of utility connection. 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-loss and topology states” at the input and “Assigned island response” at the output. Protection and controller responses require coordination. 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-loss and topology states. Identify its source device or document and the state represented on the drawing. - Follow the named output: Assigned island response. Cross-reference its destination and separate the command from confirmation that the equipment responded. - Protection and controller responses require coordination. - 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-loss and topology states. - Identify the destination and defined state of assigned island response. - Record the equipment or control-document revision supporting this functional block. - Check this application limit in the project design: Protection and controller responses require coordination. ## Important distinction Protection and controller responses require coordination. 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-loss and topology states - Output / connection: Assigned island response - Lookup label: MURC 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.