# Tap-changer operation-complete feedback

Canonical URL: https://eloragrid.ai/symbols/tap-changer-operation-complete-feedback
Publisher: Elora Grid
Updated: 2026-11-03
Lookup label: TOF
Drawing use: Schematic
Reference families: Manufacturer

Representation: Functional block
Installation focus: substations
Input: Completed-position feedback
Output: Tap-change completion status

Confirms completion of the defined tap-changing operation at the regulator interface.

## In plain English

### What this block does

Confirms completion of the defined tap-changing operation at the regulator interface.

### A simple example

In a substation, a voltage regulator can request a tap change and check the resulting tap-position feedback. A separate controller stages cooling equipment according to the transformer manufacturer's defined conditions. For this reference, the drawing identifies “Completed-position feedback” at the input and “Tap-change completion status” at the output. Completion indication must use the actual mechanism signals.

### What the drawings help you do

Start at the named input: Completed-position feedback. Identify its source device or document and the state represented on the drawing. Follow the named output: Tap-change completion status. Cross-reference its destination and separate the command from confirmation that the equipment responded.

### Terms

- Input: Completed-position feedback
- Output: Tap-change completion status
- Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Concept diagram: Completed-position feedback → TOF → Tap-change completion status
A reading guide. The entry's original illustration and input/output facts describe this application.

- [SEL-2414 transformer monitor](https://selinc.com/products/2414/)


## What it represents

Confirms completion of the defined tap-changing operation at the regulator interface. Transformer regulation changes the selected winding connection to influence voltage, while cooling control manages the installed fans and pumps. Commands, mechanical position and measured results belong to different parts of the diagram.
In a substation, a voltage regulator can request a tap change and check the resulting tap-position feedback. A separate controller stages cooling equipment according to the transformer manufacturer's defined conditions. For this reference, the drawing identifies “Completed-position feedback” at the input and “Tap-change completion status” at the output. Completion indication must use the actual mechanism signals.
Keep tap-change permission, limit contacts, movement indication and measured voltage distinct. Actual tap positions, time delays, cooling ratings and allowable parallel operation require the selected transformer control design. 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: Completed-position feedback. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Tap-change completion status. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Completion indication must use the actual mechanism signals.
- Keep tap-change permission, limit contacts, movement indication and measured voltage distinct. Actual tap positions, time delays, cooling ratings and allowable parallel operation require the selected transformer control design.

## Information to show or reference

- Label the source and connection reference for completed-position feedback.
- Identify the destination and defined state of tap-change completion status.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: Completion indication must use the actual mechanism signals.

## Important distinction

Completion indication must use the actual mechanism signals. 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: Completed-position feedback
- Output / connection: Tap-change completion status
- Lookup label: TOF is a library lookup label, not a standard device designation.

## Public references

- [SEL-2414 transformer monitor](https://selinc.com/products/2414/) — SEL. Public technical context for transformer regulation and cooling control. Transformer temperature, cooling, tap changing and parallel operation. 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.