G 3PH SYNC
Three-phase synchronous generator
A three-phase synchronous generator supplies a documented AC source associated with its mechanical prime mover and excitation system.
SLD / Schematic
Symbols · HG
Hydro turbine generator
A water turbine driving a generator, used for mini and micro hydro sources within microgrids and remote supplies.
In plain English
What does Hydro turbine generator mean?
A hydro turbine generator converts water flow and head into electrical power through a Pelton, Francis, Kaplan or crossflow turbine driving a synchronous or induction generator. In microgrids, small hydro is valuable because it is dispatchable within the limits of the water available and supplies real rotating inertia.
A simple example
Drawings show a turbine element on the shaft line to the generator circle, sometimes with a governor or a dump-load controller attached. Very small run-of-river units often regulate frequency by diverting surplus power to a ballast load rather than adjusting water flow, so the dump load may appear beside the generator.
What the drawings help you do
The symbol does not state head, flow, runaway speed or whether the unit can operate isolated. Penstock and water-hammer constraints limit how quickly load can change, which is not visible on the electrical drawing.
This particular reference
A water turbine driving a generator, used for mini and micro hydro sources within microgrids and remote supplies. A hydro unit is driven by water; its control differs from a thermal genset because load changes are limited by penstock dynamics.
- Schematic
- A drawing showing function and connections rather than physical appearance.
Read the source: AutoCAD Electrical: Power station and substation concepts · IEEE/ANSI 315-1975: graphic symbols for electrical and electronics diagrams
SLD · HG
What it represents
A hydro turbine generator converts water flow and head into electrical power through a Pelton, Francis, Kaplan or crossflow turbine driving a synchronous or induction generator. In microgrids, small hydro is valuable because it is dispatchable within the limits of the water available and supplies real rotating inertia.
Drawings show a turbine element on the shaft line to the generator circle, sometimes with a governor or a dump-load controller attached. Very small run-of-river units often regulate frequency by diverting surplus power to a ballast load rather than adjusting water flow, so the dump load may appear beside the generator.
The symbol does not state head, flow, runaway speed or whether the unit can operate isolated. Penstock and water-hammer constraints limit how quickly load can change, which is not visible on the electrical drawing.
How to read it
- A ballast or dump load beside a small hydro set indicates electronic load control instead of a mechanical governor.
- Check whether the generator is synchronous or induction.
Information to show or reference
- State turbine type, head and flow.
- Show governor or load controller.
- Reference generator type and protection.
A distinction that matters
A hydro unit is driven by water; its control differs from a thermal genset because load changes are limited by penstock dynamics.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
AutoCAD Electrical: Power station and substation concepts
Public power station representation used as site-level context.
IEEE/ANSI 315-1975: graphic symbols for electrical and electronics diagrams
Graphic-symbol standards context for rotating machines.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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