# Current unbalance / negative sequence

Canonical URL: https://eloragrid.ai/protection-functions/46-current-unbalance
Publisher: Elora Grid
Updated: 2026-10-13
Lookup label: 46
Drawing use: SLD, Schematic
Reference families: IEEE / ANSI

A current phase-balance or reverse-phase function used in documented protection applications.

## What it represents

Device function number 46 is associated with reverse-phase or phase-balance current protection. Manufacturer implementations often use negative-sequence or current-unbalance quantities. The implementation, measurement basis and protected equipment must be identified in the protection documentation.
On a power drawing, keep this function reference connected to the selected equipment and its complete designation. A multifunction relay can implement several numbered functions. This entry explains the reference; it supplies no settings or commissioning procedure.

## How to read it

- Identify the phase-current measurements used by the device.
- Confirm the manufacturer name and implementation rather than relying only on the number.

## Information to show or reference

- Reference phase-current inputs.
- Identify the protected machine or circuit.
- Link the selected relay function documentation.

## Important distinction

Current unbalance and voltage phase-sequence or balance functions use different measured quantities. Identify the element explicitly.

## Facts

- ANSI / IEEE function number: 46
- Equipment implementation: Consult the selected device manual
- Suffix interpretation: Application and manufacturer documentation

## Public references

- [Public reference table of ANSI device-function numbers](https://www.se.com/es/es/faqs/FA34639/) — Schneider Electric. Public manufacturer table used to check the base function-number name.
- [IEEE C37.2-2022: power-system device function numbers](https://ieeexplore.ieee.org/document/9984140) — IEEE. Normative publication reference for the device-function convention.
- [Relion 620: functions, codes and symbols](https://techdoc.relays.protection-control.abb/r/620-series-IEC-60870-5-103-Point-List-Manual/2.0-FP1-IEC/en-US/Functions-codes-and-symbols) — ABB. Public examples of manufacturer-specific function names and suffixes.

## 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.