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Neutral-to-earth link
The single link bonding the neutral bar to the earth bar at the point where a TN-C-S supply splits into N and PE.
IEC
IEEE / ANSI · MBJ
ANSI/IEEE main bonding jumper symbol
US-practice bonding jumper between the grounded neutral and the equipment grounding system at the service.
In plain English
What does ANSI/IEEE main bonding jumper mean?
In North American practice the main bonding jumper connects the grounded conductor, the neutral, to the equipment grounding conductor and enclosure at the service equipment. Its function corresponds to the neutral-to-earth link in TN-C-S systems. Single-line diagrams show it at the service disconnect, and separately derived systems have a corresponding system bonding jumper.
A simple example
This illustration is an independent explanation and not an IEEE graphic. Only one bond should exist per service or separately derived system. Sizing rules come from the applicable electrical code, and the drawing should state the conductor or strap size.
What the drawings help you do
Locate the bond at the service or derived system source only. Check for unwanted downstream neutral to ground bonds. A main bonding jumper bonds neutral and ground at the service; an equipment bonding jumper bonds metal parts together.
This particular reference
US-practice bonding jumper between the grounded neutral and the equipment grounding system at the service. A main bonding jumper bonds neutral and ground at the service; an equipment bonding jumper bonds metal parts together.
- Schematic
- A drawing showing function and connections rather than physical appearance.
Read the source: IEEE/ANSI 315-1975: graphic symbols for electrical and electronics diagrams · Autodesk IEEE Symbol Preview — Miscellaneous
IEEE / ANSI · Main bonding jumper form
Independent illustration in IEEE drafting context; no equivalence of every detailed standard graphic is asserted.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
SLD / Schematic · MBJ
What it represents
In North American practice the main bonding jumper connects the grounded conductor, the neutral, to the equipment grounding conductor and enclosure at the service equipment. Its function corresponds to the neutral-to-earth link in TN-C-S systems. Single-line diagrams show it at the service disconnect, and separately derived systems have a corresponding system bonding jumper.
This illustration is an independent explanation and not an IEEE graphic. Only one bond should exist per service or separately derived system. Sizing rules come from the applicable electrical code, and the drawing should state the conductor or strap size.
How to read it
- Locate the bond at the service or derived system source only.
- Check for unwanted downstream neutral to ground bonds.
Information to show or reference
- Show the jumper at the service equipment.
- State jumper size.
- Show system bonding jumpers on separately derived systems.
A distinction that matters
A main bonding jumper bonds neutral and ground at the service; an equipment bonding jumper bonds metal parts together.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
IEEE/ANSI 315-1975: graphic symbols for electrical and electronics diagrams
Graphic-symbol standards context and official status; not a source of reproduced artwork.
Autodesk IEEE Symbol Preview — Miscellaneous
Public IEEE-oriented earth and bonding forms.
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.
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