# Neutral conductor mark

Canonical URL: https://eloragrid.ai/symbols/iec-neutral-conductor-mark
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: N
Drawing use: SLD, Schematic
Reference families: IEC

## Symbol convention

Convention: IEC
Form: Neutral conductor identification on a conductor group
Independent IEC-context illustration; not certified IEC geometry.

A mark on a single-line conductor group identifying which conductor is the neutral, often drawn as a small circle on a stroke.

## In plain English

### What does Neutral conductor mark mean?

When a single line represents a group of conductors, one of them can be identified as the neutral with a distinct mark on its stroke, together with the letter N where clarity requires. This lets a single-line diagram tell a three-phase three-wire feeder from a three-phase four-wire feeder without expanding to multi-line form.

### A simple example

The mark identifies the neutral but does not say whether the neutral is fully rated, reduced or oversized for harmonic loading. It also does not show where the neutral is earthed. System earthing is a separate decision shown at the source, for example a star point to earth connection or a neutral earthing resistor.

### What the drawings help you do

Check whether the feeder carries a neutral before assuming four-wire loads are supported. Look at the source to see how the neutral is earthed. A neutral mark identifies the N conductor; a PEN mark identifies a combined neutral and protective conductor with different switching rules.

### This particular reference

A mark on a single-line conductor group identifying which conductor is the neutral, often drawn as a small circle on a stroke. A neutral mark identifies the N conductor; a PEN mark identifies a combined neutral and protective conductor with different switching rules.

### Terms

- Phase: One of the related AC waveforms in a power system.
- Terminal: An identified point where a conductor connects.
- 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.

- [Definition of standardised earthing schemes](https://www.electrical-installation.org/enwiki/Definition_of_standardised_earthing_schemes)
- [IEC-60617 symbol preview directory](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-7871E6EF-24D5-467E-9B74-321FEDC9DFDA.htm)


## What it represents

When a single line represents a group of conductors, one of them can be identified as the neutral with a distinct mark on its stroke, together with the letter N where clarity requires. This lets a single-line diagram tell a three-phase three-wire feeder from a three-phase four-wire feeder without expanding to multi-line form.
The mark identifies the neutral but does not say whether the neutral is fully rated, reduced or oversized for harmonic loading. It also does not show where the neutral is earthed. System earthing is a separate decision shown at the source, for example a star point to earth connection or a neutral earthing resistor.

## How to read it

- Check whether the feeder carries a neutral before assuming four-wire loads are supported.
- Look at the source to see how the neutral is earthed.

## Information to show or reference

- Mark the neutral on each four-wire feeder.
- State neutral sizing where it differs from phase conductors.
- Show neutral switching or links where the scheme requires them.

## Important distinction

A neutral mark identifies the N conductor; a PEN mark identifies a combined neutral and protective conductor with different switching rules.

## Facts

- Graphic cue: Distinct tick or small circle on one stroke of a conductor group
- Letter code: N
- Preview: Original educational illustration; consult the publisher and applicable standard for the exact graphic

## Public references

- [Definition of standardised earthing schemes](https://www.electrical-installation.org/enwiki/Definition_of_standardised_earthing_schemes) — Schneider Electric, Electrical Installation Guide. Public installation-guide definitions of earthing schemes and the role of the neutral conductor.
- [IEC-60617 symbol preview directory](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-7871E6EF-24D5-467E-9B74-321FEDC9DFDA.htm) — Autodesk. Public directory of IEC-oriented symbol families.

## 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.