Generator symbol
Also called Genset, Alternator
A generator converts mechanical power into electrical power. On a one-line it is a source, usually drawn at the top with its breaker below it.
What the generator symbol means
A generator converts mechanical power into electrical power. On a one-line it is a source, usually drawn at the top with its breaker below it.
ANSI and IEC symbols
A circle with a sine wave or the letter G, often with the rating written beside it.
ANSI SVGWhere you see it
Main and emergency power generation, gas turbine and diesel generators on offshore units, standby gensets.
What is written next to it
On a one-line, the generator carries its tag and its ratings: rating in kVA or MVA, voltage, power factor, speed and subtransient reactance, with the neutral earthing beside it.
What gets checked at commissioning
Before the generator is energised, the test records usually cover: insulation resistance and polarisation index, winding resistance, protection injection, synchronising checks and load tests. 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 generator:
- 32 reverse power
- 40 loss of field
- 46 negative sequence
- 87G generator differential
See the full list of ANSI device numbers with their IEC equivalents.
Related symbols
Frequently asked questions
What does the generator symbol look like?
On ANSI drawings: A circle with a sine wave or the letter G, often with the rating written beside it. In IEC 60617: The general machine symbol, a circle, with G for generator and a tilde for alternating current.
Is the generator symbol the same in IEC and ANSI?
No. The general machine symbol, a circle, with G for generator and a tilde for alternating current. The IEC 60617 number is S00819.
Where is a generator used?
Main and emergency power generation, gas turbine and diesel generators on offshore units, standby gensets.
Which ANSI device numbers go with a generator?
32 reverse power, 40 loss of field, 46 negative sequence, 87G generator differential.
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