# ANSI/IEEE Phase-to-neutral voltmeter selector form

Canonical URL: https://eloragrid.ai/symbols/ansi-phase-to-neutral-voltmeter-selector
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: HSW1S91
Drawing use: Schematic
Reference families: IEEE / ANSI, Manufacturer

## Symbol convention

Convention: IEEE / ANSI
Form: 3 Voltage Phase-to-Neutral Switch
Autodesk IEEE Symbol Preview: Miscellaneous Switches, block HSW1S91. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier.
Related representation: [Phase-to-neutral voltmeter selector](https://eloragrid.ai/symbols/iec-phase-to-neutral-voltmeter-selector)

IEEE-library form of phase-to-neutral voltmeter selector: this representation identifies selection among phase-to-neutral voltage measurement connections.

## In plain English

### What does ANSI/IEEE Phase-to-neutral voltmeter selector form mean?

This reference locates phase-to-neutral voltmeter selector in Autodesk's IEEE-oriented miscellaneous switches family. This representation identifies selection among phase-to-neutral voltage measurement connections. The meter is connected to the selected phase relative to the documented neutral or reference point. That connection differs from measuring between two phase conductors. The public library uses HSW1S91 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number.

### A simple example

Read the operating mechanism and the contact reference state together. Cross-reference every associated contact to the same device and show which movement, signal or reset changes its condition; the symbol alone does not establish the complete switching sequence.

### What the drawings help you do

Show the reference terminal and each selectable measurement path. The position table should make clear which reading the operator receives at each position. Show the neutral/reference connection and each selected phase in the position table. Phase-to-neutral and phase-to-phase measurements have different connection paths. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted.

### This particular reference

IEEE-library form of phase-to-neutral voltmeter selector: this representation identifies selection among phase-to-neutral voltage measurement connections. Phase-to-neutral and phase-to-phase measurements have different connection paths.

### Terms

- Normally open / normally closed: The contact state in the normal condition defined for the drawing.
- Phase: One of the related AC waveforms in a power system.
- Terminal: An identified point where a conductor connects.

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.

- [Autodesk IEEE Symbol Preview — Miscellaneous Switches](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-278F6C21-B1A6-4EA1-A535-E78D53BBD10D.htm)


## What it represents

This reference locates phase-to-neutral voltmeter selector in Autodesk's IEEE-oriented miscellaneous switches family. This representation identifies selection among phase-to-neutral voltage measurement connections. The meter is connected to the selected phase relative to the documented neutral or reference point. That connection differs from measuring between two phase conductors. The public library uses HSW1S91 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number.
Read the operating mechanism and the contact reference state together. Cross-reference every associated contact to the same device and show which movement, signal or reset changes its condition; the symbol alone does not establish the complete switching sequence.
Show the reference terminal and each selectable measurement path. The position table should make clear which reading the operator receives at each position. Show the neutral/reference connection and each selected phase in the position table. Phase-to-neutral and phase-to-phase measurements have different connection paths. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted.

## How to read it

- Show the neutral/reference connection and each selected phase in the position table.
- Phase-to-neutral and phase-to-phase measurements have different connection paths.

## Information to show or reference

- Identify the associated device, circuit or diagram boundary.
- Show the neutral/reference connection and each selected phase in the position table.
- Cross-reference the equipment data, terminal mapping or operating-state legend needed to interpret the form.

## Important distinction

Phase-to-neutral and phase-to-phase measurements have different connection paths.

## Facts

- Convention evidence: Autodesk IEEE Symbol Preview: Miscellaneous Switches; published form: 3 Voltage Phase-to-Neutral Switch.
- Public vendor block: HSW1S91. Vendor library token, not an IEEE symbol number.
- Information added: Show the neutral/reference connection and each selected phase in the position table.
- Preview: Independent educational concept; consult the publisher and applicable standard for the exact graphic
- Artwork scope: Original educational geometry. Exact standard graphics, product ratings and terminal pinouts are not certified.

## Public references

- [Autodesk IEEE Symbol Preview — Miscellaneous Switches](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-278F6C21-B1A6-4EA1-A535-E78D53BBD10D.htm) — Autodesk. Public IEEE-oriented Miscellaneous Switches table explicitly lists HSW1S91 as 3 Voltage Phase-to-Neutral Switch. This supports the vendor convention context, not reproduction of the publisher graphic.

## 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.
