Symbol 5017 from IEC 60417 - Title/Meaning: Earth; ground Function/description: To identify an earth (ground) terminal in cases where neither the symbol 5018 nor 5019 is explicitly required.
Additional information: 
Title was editorially improved.
Own work using: iso.org/obp/graphics/grs/78f0d7db-9187-436b-885b-84c4d7451f44 200.png
Vectorization:  Mrmw