# Microgrid multiple-PCC synchronising selection

Canonical URL: https://eloragrid.ai/symbols/microgrid-multiple-pcc-synchronising-selection
Publisher: Elora Grid
Updated: 2026-11-03
Lookup label: MMSS
Drawing use: Schematic
Reference families: Manufacturer

Representation: Functional block
Installation focus: microgrids
Input: PCC selection and topology
Output: Selected synchronising interface

Selects the named interconnection point and voltage references for the assigned synchronising transaction.

## In plain English

### What this block does

Selects the named interconnection point and voltage references for the assigned synchronising transaction.

### A simple example

In a microgrid reconnecting at its point of common coupling, a synchroniser can adjust the island reference while a separate permissive confirms the permitted relationship across the open breaker. For this reference, the drawing identifies “PCC selection and circuit arrangement” at the input and “Selected synchronising interface” at the output. The other interconnection paths must be considered.

### What the drawings help you do

Start at the named input: PCC selection and circuit arrangement. Identify its source device or document and the state represented on the drawing. Follow the named output: Selected synchronising interface. Cross-reference its destination and separate the command from confirmation that the equipment responded.

### Terms

- Input: PCC selection and topology
- Output: Selected synchronising interface
- Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Concept diagram: PCC selection and topology → MMSS → Selected synchronising interface
A reading guide. The entry's original illustration and input/output facts describe this application.

- [Microgrid Flex components and control design](https://productinfo.se.com/microgrid_guide/0100db2503_ecostruxure-microgrid-flex_design-guide_iec/English/0100DB2503-Microgrid%20Flex%20Design%20Guide-IEC-Optimize%20%28bookmap%29_DD00654397.XML.xml/%24/MicrogridFlexComponents-3A7DD96C)


## What it represents

Selects the named interconnection point and voltage references for the assigned synchronising transaction. Synchronising control compares two AC systems before their assigned connecting breaker closes. Voltage magnitude, frequency, phase relationship, breaker readiness and command authority are separate inputs to the closing decision.
In a microgrid reconnecting at its point of common coupling, a synchroniser can adjust the island reference while a separate permissive confirms the permitted relationship across the open breaker. For this reference, the drawing identifies “PCC selection and topology” at the input and “Selected synchronising interface” at the output. The other interconnection paths must be considered.
Identify the two measurement sides and the equipment receiving any adjustment request. Closing limits, breaker timing and loss-of-measurement behavior require the approved synchronising design. 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: PCC selection and topology. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Selected synchronising interface. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- The other interconnection paths must be considered.
- Identify the two measurement sides and the equipment receiving any adjustment request. Closing limits, breaker timing and loss-of-measurement behavior require the approved synchronising design.

## Information to show or reference

- Label the source and connection reference for pcc selection and topology.
- Identify the destination and defined state of selected synchronising interface.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: The other interconnection paths must be considered.

## Important distinction

The other interconnection paths must be considered. 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: PCC selection and topology
- Output / connection: Selected synchronising interface
- Lookup label: MMSS is a library lookup label, not a standard device designation.

## Public references

- [Microgrid Flex components and control design](https://productinfo.se.com/microgrid_guide/0100db2503_ecostruxure-microgrid-flex_design-guide_iec/English/0100DB2503-Microgrid%20Flex%20Design%20Guide-IEC-Optimize%20%28bookmap%29_DD00654397.XML.xml/%24/MicrogridFlexComponents-3A7DD96C) — Schneider Electric. Public technical context for microgrid synchronising interfaces. Microgrid power and control interfaces, synchronisation and source coordination. 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.