# Station battery low-voltage alarm block

Canonical URL: https://eloragrid.ai/symbols/station-battery-low-voltage-alarm-block
Publisher: Elora Grid
Updated: 2026-11-03
Lookup label: SBLAB
Drawing use: Schematic
Reference families: Manufacturer

Representation: Functional block
Installation focus: substations
Input: Battery-bus voltage
Output: Low-voltage alarm state

Applies the documented battery-bus low-voltage supervision to its assigned alarm output.

## In plain English

### What this block does

Applies the documented battery-bus low-voltage supervision to its assigned alarm output.

### 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 “Battery-bus voltage” at the input and “Low-voltage alarm state” at the output. Voltage is not a direct measure of usable capacity.

### What the drawings help you do

Start at the named input: Battery-bus voltage. Identify its source device or document and the state represented on the drawing. Follow the named output: Low-voltage alarm state. Cross-reference its destination and separate the command from confirmation that the equipment responded.

### Terms

- Input: Battery-bus voltage
- Output: Low-voltage alarm state
- Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Concept diagram: Battery-bus voltage → SBLAB → Low-voltage alarm state
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

Applies the documented battery-bus low-voltage supervision to its assigned alarm output. 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 “Battery-bus voltage” at the input and “Low-voltage alarm state” at the output. Voltage is not a direct measure of usable capacity.
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: Battery-bus voltage. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Low-voltage alarm state. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Voltage is not a direct measure of usable capacity.
- 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 battery-bus voltage.
- Identify the destination and defined state of low-voltage alarm state.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: Voltage is not a direct measure of usable capacity.

## Important distinction

Voltage is not a direct measure of usable capacity. 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: Battery-bus voltage
- Output / connection: Low-voltage alarm state
- Lookup label: SBLAB 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.