Earthing switch symbol
Also called Grounding switch, Earth switch
An earthing switch connects a de-energised circuit to earth so it is safe to work on.
What the earthing switch symbol means
An earthing switch connects a de-energised circuit to earth so it is safe to work on.
ANSI and IEC symbols
Where you see it
On cable feeders and busbars in medium voltage switchgear, interlocked with the breaker or disconnector.
What is written next to it
On a one-line, the earthing switch carries its tag and its ratings: short-time and making current rating.
What gets checked at commissioning
Before the earthing switch is energised, the test records usually cover: operation, interlocks with the breaker or disconnector, and continuity of the earth connection. 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 earthing switch:
- 57 grounding device
See the full list of ANSI device numbers with their IEC equivalents.
Related symbols
Frequently asked questions
What does the earthing switch symbol look like?
On ANSI drawings: A switch blade to the ground symbol. In IEC 60617: A disconnector connected to the earth symbol.
Is the earthing switch symbol the same in IEC and ANSI?
No. A disconnector connected to the earth symbol. The IEC 60617 number is S00288 + S00200.
Where is a earthing switch used?
On cable feeders and busbars in medium voltage switchgear, interlocked with the breaker or disconnector.
Which ANSI device numbers go with a earthing switch?
57 grounding device.
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