Y N
Star winding with accessible neutral
An accessible-neutral star winding brings the common star point to a documented terminal.
SLD / Schematic
Symbols · -
Direct neutral earthing connection
A transformer or generator star point connected straight to earth with no intentional impedance, as in a solidly earthed system.
In plain English
What does Direct neutral earthing connection mean?
This representation shows a star point connected directly to an earth symbol. It marks a solidly earthed system, which gives high earth fault current and allows ordinary overcurrent devices to clear earth faults quickly. It is standard on most low voltage distribution systems and common on transmission networks.
A simple example
The symbol does not tell you whether there are several earthing points on the network or the earth electrode arrangement. It also excludes resistance, reactance and resonant earthing, which are shown with impedance symbols between the star point and earth. Earth fault protection settings depend heavily on this choice.
What the drawings help you do
Confirm there is no earthing impedance between star point and earth. Check earth fault protection is suited to high fault current. A direct neutral earthing connection has no impedance; resistance earthing inserts a resistor to limit fault current.
This particular reference
A transformer or generator star point connected straight to earth with no intentional impedance, as in a solidly earthed system. A direct neutral earthing connection has no impedance; resistance earthing inserts a resistor to limit fault current.
- Terminal
- An identified point where a conductor connects.
- Rating
- A value stating the conditions for which equipment is specified.
- Schematic
- A drawing showing function and connections rather than physical appearance.
Read the source: Definition of standardised earthing schemes · AutoCAD Electrical: Earthing, sources and surge protection
SLD · -
What it represents
This representation shows a star point connected directly to an earth symbol. It marks a solidly earthed system, which gives high earth fault current and allows ordinary overcurrent devices to clear earth faults quickly. It is standard on most low voltage distribution systems and common on transmission networks.
The symbol does not tell you whether there are several earthing points on the network or the earth electrode arrangement. It also excludes resistance, reactance and resonant earthing, which are shown with impedance symbols between the star point and earth. Earth fault protection settings depend heavily on this choice.
How to read it
- Confirm there is no earthing impedance between star point and earth.
- Check earth fault protection is suited to high fault current.
Information to show or reference
- Show the star point and earth connection.
- State the earthing conductor size.
- Record the earthing arrangement in the system notes.
A distinction that matters
A direct neutral earthing connection has no impedance; resistance earthing inserts a resistor to limit fault current.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Definition of standardised earthing schemes
Public installation-guide definitions of system earthing arrangements.
AutoCAD Electrical: Earthing, sources and surge protection
Public IEC-oriented earth 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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