# Volt-squared-hour meter

Canonical URL: https://eloragrid.ai/symbols/volt-squared-hour-meter
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: V²h
Drawing use: Schematic
Reference families: IEC

Integrating meter that totalises the square of voltage over time, used to assess voltage-dependent losses and stress.

## In plain English

### What does Volt-squared-hour meter mean?

A volt-squared-hour meter integrates the square of voltage over time. Quantities such as iron losses in transformers and the stress on some insulation vary roughly with voltage squared, so the register gives a measure of exposure that a simple time-at-voltage record would not.

### A simple example

It is uncommon on modern drawings and is often provided as a calculated register inside a multifunction meter. The symbol does not tell you the reference voltage or whether the value is per phase or combined, so the meter documentation is needed to use the reading.

### What the drawings help you do

Check whether the value is per phase or combined. Confirm whether this is a separate meter or a calculated register. A V²h meter integrates voltage squared; a kWh meter integrates power.

### This particular reference

Integrating meter that totalises the square of voltage over time, used to assess voltage-dependent losses and stress. A V²h meter integrates voltage squared; a kWh meter integrates power.

### Terms

- Winding: A coil of conductor inside an electrical machine or transformer.
- Phase: One of the related AC waveforms in a power system.
- Rating: A value stating the conditions for which equipment is specified.

Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference
A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/)


## What it represents

A volt-squared-hour meter integrates the square of voltage over time. Quantities such as iron losses in transformers and the stress on some insulation vary roughly with voltage squared, so the register gives a measure of exposure that a simple time-at-voltage record would not.
It is uncommon on modern drawings and is often provided as a calculated register inside a multifunction meter. The symbol does not tell you the reference voltage or whether the value is per phase or combined, so the meter documentation is needed to use the reading.

## How to read it

- Check whether the value is per phase or combined.
- Confirm whether this is a separate meter or a calculated register.

## Information to show or reference

- Show VT source
- State reference voltage
- Reference meter documentation

## Important distinction

A V²h meter integrates voltage squared; a kWh meter integrates power.

## Facts

- Integrated quantity: Voltage squared over time
- Typical use: Loss and stress assessment
- Preview: Independent educational concept; consult the applicable standard and project legend for the exact graphic

## Public references

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/) — IEC. IEC context for graphical symbols used in diagrams; no IEC graphic is reproduced.

## 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.