Six Ground Symbols and What Each One Promises

Full article on JLCPCB: https://jlcpcb.com/blog/ground-symbols-explained

Four ground marks are numbered in IEC 60417: 5017 earth, 5018 functional earth, 5019 protective earth, 5020 chassis. Only 5019, the earth mark inside a circle, may identify a protective earth terminal. Use 5018 there instead and you have not made a drafting slip, you have made a compliance failure.

Quick-reference chart of all six ground symbols with their standard numbers

The Six Marks

Six symbols cover almost every schematic and equipment label. Four are numbered by IEC 60417, which standardises markings placed on equipment; the other two come from IEEE 315, which standardises symbols drawn on diagrams.

· 5017, three shrinking bars — earth, general (IEEE 315 clause 3.9.1)

· 5018, earth mark under an arc — functional or noiseless earth (3.9.1.1)

· 5019, earth mark inside a circle — protective earth (3.9.1.2)

· 5020, bar with three angled strokes — chassis or frame (3.9.2)

· Triangle, solid or hollow — signal or common ground (clause 3.9.3)

· Triangle lettered AGND, DGND or PGND — one named 0 V return among several

IEC 60417 and IEEE 315 ground symbols compared side by side

Where the Stem Stops

One drawing detail separates a correct protective earth mark from the most widely copied error in the industry. In IEC 60417-5019 the vertical stem stops inside the circle and never touches it. The 2011 edition of NFPA 70, the US National Electrical Code, carried an informational note figure for an equipment grounding conductor termination point drawn with the bar touching the circle. Two further tells: the 5017 bars must shorten as they descend, and 5018 never substitutes for 5019.

The protective earth symbol, stem stopping short of the circle

Net Names Win

In every mainstream EDA tool the net name decides what connects, not the picture. Altium states it plainly: the net name determines which net a power port joins, not the style of the symbol. Three ports drawn as Earth, Bar and Signal Ground all land on GND if all three are named GND. To create a genuinely separate return, name it AGND everywhere it belongs, join it to GND at exactly one point with a 0 Ω link or net tie, then run ERC and confirm two nets joined once.

The full six-symbol chart, the IEC 60417 versus IEEE 315 mapping and the tool-by-tool net rules for KiCad, Altium and EasyEDA are in the complete guide: Read the full guide