# Station DC dual-bus segregation

Canonical URL: https://eloragrid.ai/symbols/station-dc-dual-bus-segregation
Publisher: Elora Grid
Updated: 2026-11-03
Lookup label: SDDS
Drawing use: Schematic
Reference families: Manufacturer

Representation: Functional block
Installation focus: substations
Input: Two DC bus systems
Output: Segregated outgoing supplies

Keeps two separately assigned station DC distribution buses identifiable across their outgoing circuits.

## In plain English

### What this block does

Keeps two separately assigned station DC distribution buses identifiable across their outgoing circuits.

### A simple example

In a substation control building, the battery can support breaker trip circuits while the charger AC supply is unavailable. Supervision must identify whether the charger, battery or a downstream feeder is affected. For this reference, the drawing identifies “Two DC bus systems” at the input and “Segregated outgoing supplies” at the output. Shared battery or charger dependencies must be shown.

### What the drawings help you do

Start at the named input: Two DC bus systems. Identify its source device or document and the state represented on the drawing. Follow the named output: Segregated outgoing supplies. Cross-reference its destination and separate the command from confirmation that the equipment responded.

### Terms

- Input: Two DC bus systems
- Output: Segregated outgoing supplies
- Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Concept diagram: Two DC bus systems → SDDS → Segregated outgoing supplies
A reading guide. The entry's original illustration and input/output facts describe this application.

- [MicroGenius S2/S4 battery charger technical manual](https://www.sens-usa.com/hubfs/Controlled%20Files/Manuals/101330_MGS_User_Manual.pdf)


## What it represents

Keeps two separately assigned station DC distribution buses identifiable across their outgoing circuits. A station battery system supplies protection, control and other assigned DC loads through a documented charger and distribution arrangement. Charger output, battery contribution and load distribution are related but separately monitored paths.
In a substation control building, the battery can support breaker trip circuits while the charger AC supply is unavailable. Supervision must identify whether the charger, battery or a downstream feeder is affected. For this reference, the drawing identifies “Two DC bus systems” at the input and “Segregated outgoing supplies” at the output. Shared battery or charger dependencies must be shown.
Identify every source, protective device, isolation boundary and return. Battery capacity, DC fault duty, charging settings and ventilation require the selected battery-system design; illustrative circuits do not establish autonomy. 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: Two DC bus systems. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Segregated outgoing supplies. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Shared battery or charger dependencies must be shown.
- Identify every source, protective device, isolation boundary and return. Battery capacity, DC fault duty, charging settings and ventilation require the selected battery-system design; illustrative circuits do not establish autonomy.

## Information to show or reference

- Label the source and connection reference for two dc bus systems.
- Identify the destination and defined state of segregated outgoing supplies.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: Shared battery or charger dependencies must be shown.

## Important distinction

Shared battery or charger dependencies must be shown. 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: Substations
- Input / boundary: Two DC bus systems
- Output / connection: Segregated outgoing supplies
- Lookup label: SDDS is a library lookup label, not a standard device designation.

## Public references

- [MicroGenius S2/S4 battery charger technical manual](https://www.sens-usa.com/hubfs/Controlled%20Files/Manuals/101330_MGS_User_Manual.pdf) — SENS. Public technical context for station battery and charger distribution. Battery charging modes, DC distribution interfaces and charger alarms. 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.