BAT
Battery
An electrochemical electrical source or storage element represented in a circuit.
SLD / Schematic
Symbols · GB ±
Centre-tapped battery bank
A battery bank with a mid-point connection that provides positive and negative rails about a common centre point.
In plain English
What does Centre-tapped battery bank mean?
A centre-tapped battery bank brings out a connection at the middle of the series chain, giving positive and negative rails referred to that point. It is used in some UPS rectifier-inverter designs, three-level converters and telecom or substation DC systems that need a symmetric supply or a defined midpoint for earth-fault detection.
A simple example
Drawings show the battery symbol split into two halves with a lead taken from the junction, often labelled N, M or 0 V. The midpoint may be earthed, earthed through a resistance or left floating with an insulation monitor, and the drawing should state which.
What the drawings help you do
The symbol does not show how the two halves are kept balanced. Unequal loading on the two rails discharges one half faster, and the midpoint earthing method changes how an earth fault on either rail behaves.
This particular reference
A battery bank with a mid-point connection that provides positive and negative rails about a common centre point. A centre-tapped bank has a usable midpoint; an ordinary battery string presents only positive and negative terminals.
- DC
- Direct current: electricity flowing in one direction.
- Terminal
- An identified point where a conductor connects.
- Schematic
- A drawing showing function and connections rather than physical appearance.
Read the source: IEC graphical symbols for diagrams · Multilevel NPC converter application context
SLD / Schematic · GB ±
What it represents
A centre-tapped battery bank brings out a connection at the middle of the series chain, giving positive and negative rails referred to that point. It is used in some UPS rectifier-inverter designs, three-level converters and telecom or substation DC systems that need a symmetric supply or a defined midpoint for earth-fault detection.
Drawings show the battery symbol split into two halves with a lead taken from the junction, often labelled N, M or 0 V. The midpoint may be earthed, earthed through a resistance or left floating with an insulation monitor, and the drawing should state which.
The symbol does not show how the two halves are kept balanced. Unequal loading on the two rails discharges one half faster, and the midpoint earthing method changes how an earth fault on either rail behaves.
How to read it
- Identify how the midpoint is earthed or monitored.
- Check whether loads draw from one half only.
Information to show or reference
- State voltage of each half and total.
- Show midpoint earthing or monitoring.
- Reference balancing and fault detection.
A distinction that matters
A centre-tapped bank has a usable midpoint; an ordinary battery string presents only positive and negative terminals.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
IEC graphical symbols for diagrams
IEC graphical symbol context for batteries.
Multilevel NPC converter application context
Public three-level converter context requiring a DC midpoint.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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