# Active-power transducer

Canonical URL: https://eloragrid.ai/symbols/active-power-transducer
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: P/I
Drawing use: Schematic, SLD
Reference families: IEC, Manufacturer

Measuring transducer that converts CT and VT inputs into a DC signal proportional to active power for SCADA or control.

## In plain English

### What does Active-power transducer mean?

An active-power device that turns a measured quantity into a signal takes current and voltage inputs and produces a DC current or voltage signal proportional to watts, often bipolar so that export and import give opposite signs. It is used where a governor, load controller or older SCADA needs an analogue power signal.

### A simple example

The output range, including how negative power is represented, must match the receiving input. The symbol shows the conversion but not the element configuration, response time or the scaling between rated power and output signal.

### What the drawings help you do

Check how reverse power is represented at the output. Confirm element configuration matches the system wiring. An active-power device that turns a measured quantity into a signal outputs a signal; an active power indicator displays the value.

### This particular reference

Measuring device that turns a measured quantity into a signal that converts CT and VT inputs into a DC signal proportional to active power for SCADA or control. An active-power device that turns a measured quantity into a signal outputs a signal; an active power indicator displays the value.

### Terms

- DC: Direct current: electricity flowing in one direction.
- Signal: Electrical information passed between devices, rather than necessarily the main power supply.
- 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.

- [Analog current signal isolation](https://www.phoenixcontact.com/en-us/products/signal-conditioner-mcr-c-i-i-0b-0b-dci-2810955)
- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/)


## What it represents

An active-power transducer takes current and voltage inputs and produces a DC current or voltage signal proportional to watts, often bipolar so that export and import give opposite signs. It is used where a governor, load controller or older SCADA needs an analogue power signal.
The output range, including how negative power is represented, must match the receiving input. The symbol shows the conversion but not the element configuration, response time or the scaling between rated power and output signal.

## How to read it

- Check how reverse power is represented at the output.
- Confirm element configuration matches the system wiring.

## Information to show or reference

- State full-scale power
- State output range
- Show CT and VT inputs

## Important distinction

An active-power transducer outputs a signal; an active power indicator displays the value.

## Facts

- Inputs: CT and VT secondaries
- Output: DC signal proportional to active power
- Preview: Independent educational concept; consult the applicable standard and project legend for the exact graphic

## Public references

- [Analog current signal isolation](https://www.phoenixcontact.com/en-us/products/signal-conditioner-mcr-c-i-i-0b-0b-dci-2810955) — Phoenix Contact. Public context for analogue measuring signals and their isolation.
- [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.