N
Neutral link, open
A neutral link drawn removed or open, showing the neutral conductor disconnected at that point.
IEC
IEEE / ANSI · N
ANSI/IEEE Neutral link, open form
IEEE-library form of neutral link, open: a neutral link drawn removed or open, showing the neutral conductor disconnected at that point.
In plain English
What does ANSI/IEEE Neutral link, open form mean?
This reference locates neutral link, open in Autodesk's IEEE-oriented fuses family. The open neutral link shows the link withdrawn so that the neutral is disconnected. Drawings use it where a circuit is normally run with the neutral open, for example to isolate a spare or to segregate a neutral during a changeover, and on test procedures that show the link removed. The public library uses HFU1NLO for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number.
A simple example
Use the surrounding circuit labels and the project legend to identify the intended operating condition and connection. Carry the same device reference into the schedule or equipment document so the symbol can be reconciled with its real terminals, function and operating limits.
What the drawings help you do
An open neutral on a live four-wire circuit can cause severe overvoltage on single-phase loads, so an open link in normal service needs a clear reason on the drawing. The symbol says nothing about the phase conductors, which may still be supplied with operating power. Ask why the neutral is shown open in service. An open neutral link is disconnected; the closed form shows normal continuity. 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 neutral link, open: a neutral link drawn removed or open, showing the neutral conductor disconnected at that point. An open neutral link is disconnected; the closed form shows normal continuity.
- 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.
Read the source: Autodesk IEEE Symbol Preview — Fuses · Definition of standardised earthing schemes
IEEE / ANSI · Neutral Link - Open
Autodesk IEEE Symbol Preview: Fuses, block HFU1NLO. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
SLD / Schematic · N
What it represents
This reference locates neutral link, open in Autodesk's IEEE-oriented fuses family. The open neutral link shows the link withdrawn so that the neutral is disconnected. Drawings use it where a circuit is normally run with the neutral open, for example to isolate a spare or to segregate a neutral during a changeover, and on test procedures that show the link removed. The public library uses HFU1NLO for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number.
Use the surrounding circuit labels and the project legend to identify the intended operating condition and connection. Carry the same device reference into the schedule or equipment document so the symbol can be reconciled with its real terminals, function and operating limits.
An open neutral on a live four-wire circuit can cause severe overvoltage on single-phase loads, so an open link in normal service needs a clear reason on the drawing. The symbol says nothing about the phase conductors, which may still be energised. Ask why the neutral is shown open in service. An open neutral link is disconnected; the closed form shows normal continuity. 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
- Ask why the neutral is shown open in service.
- Check that phases are also isolated before working.
Information to show or reference
- Note the reason the link is open.
- Show phase isolation state alongside.
- Label the link with its circuit number.
A distinction that matters
An open neutral link is disconnected; the closed form shows normal continuity.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Autodesk IEEE Symbol Preview — Fuses
Public IEEE-oriented Fuses table explicitly lists HFU1NLO as Neutral Link - Open. This supports the vendor convention context, not reproduction of the publisher graphic.
Definition of standardised earthing schemes
Public installation-guide definitions of the neutral's role in earthing schemes.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
Explore related references
N
Neutral link, closed
A removable link in the neutral conductor shown in its closed position, allowing the neutral to be opened for testing.
IEC
N
Neutral conductor mark
A mark on a single-line conductor group identifying which conductor is the neutral, often drawn as a small circle on a stroke.
IEC
TB DISC
Disconnect terminal block
A disconnect terminal includes a documented separable path for circuit isolation or testing at the wiring level.
Schematic
Put the reference into a drawing workflow.
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