Ground symbol
Also called Earth, Earthing
The ground or earth symbol shows a connection to the earthing system, for example a solidly earthed transformer neutral.
What the ground symbol means
The ground or earth symbol shows a connection to the earthing system, for example a solidly earthed transformer neutral.
ANSI and IEC symbols
Where you see it
Transformer and generator neutrals, surge arresters, earthing switches and capacitor banks.
What is written next to it
On a one-line, the ground carries its tag and its ratings: the earthing arrangement, such as solid or resistance earthed.
What gets checked at commissioning
Before the ground is energised, the test records usually cover: earth electrode resistance and continuity of the bonding. Each check is recorded against the tag, so the system can be handed over with its evidence. See commissioning software.
ANSI device numbers
Protective functions you will often find with a ground:
- 51G ground overcurrent
- 64 ground detector
See the full list of ANSI device numbers with their IEC equivalents.
Related symbols
Frequently asked questions
What does the ground symbol look like?
On ANSI drawings: Three lines getting shorter. In IEC 60617: Drawn the same way. Protective earth adds a circle around it (S00202).
Is the ground symbol the same in IEC and ANSI?
Yes, it is drawn the same way in most legends.
Where is a ground used?
Transformer and generator neutrals, surge arresters, earthing switches and capacitor banks.
Which ANSI device numbers go with a ground?
51G ground overcurrent, 64 ground detector.
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