HG
Hydro turbine generator
A water turbine driving a generator, used for mini and micro hydro sources within microgrids and remote supplies.
SLD
Symbols · DLC
Dump load controller
A controller that diverts surplus generation into a resistive dump load to hold frequency or voltage in a small isolated system.
In plain English
What does Dump load controller mean?
A dump load controller keeps a small isolated system in balance by diverting surplus power into a resistive load, usually water or air heaters. In micro hydro systems it holds frequency constant by keeping total generator load fixed, and in small wind or battery systems it protects the battery from overcharge by dumping excess energy.
A simple example
Drawings show a controller block, often with a thyristor or transistor switch symbol, connected between the bus and a resistor bank labelled dump or ballast load. A frequency or voltage sensing connection to the bus is included.
What the drawings help you do
The dump load must be rated to absorb the full generator output if all consumer loads disconnect. The symbol does not show that rating or the heat rejection arrangement, both important for safety.
This particular reference
A controller that diverts surplus generation into a resistive dump load to hold frequency or voltage in a small isolated system. A dump load controller diverts surplus energy continuously; a load bank is a test load used temporarily.
- Terminal
- An identified point where a conductor connects.
- Signal
- Electrical information passed between devices, rather than necessarily the main power supply.
- Rating
- A value stating the conditions for which equipment is specified.
Read the source: Resistors and heater-element symbols · AutoCAD Electrical: Semiconductor components
SLD / Schematic · DLC
What it represents
A dump load controller keeps a small isolated system in balance by diverting surplus power into a resistive load, usually water or air heaters. In micro hydro systems it holds frequency constant by keeping total generator load fixed, and in small wind or battery systems it protects the battery from overcharge by dumping excess energy.
Drawings show a controller block, often with a thyristor or transistor switch symbol, connected between the bus and a resistor bank labelled dump or ballast load. A frequency or voltage sensing connection to the bus is included.
The dump load must be rated to absorb the full generator output if all consumer loads disconnect. The symbol does not show that rating or the heat rejection arrangement, both important for safety.
How to read it
- The resistor bank is a control element, not a consumer load.
- Check the sensing quantity: frequency for hydro, voltage for battery systems.
Information to show or reference
- State dump load rating against generator rating.
- Show sensing and switching element.
- Reference heat rejection.
A distinction that matters
A dump load controller diverts surplus energy continuously; a load bank is a test load used temporarily.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Resistors and heater-element symbols
Public resistor and heater-element symbol context.
AutoCAD Electrical: Semiconductor components
Public semiconductor switch symbol context.
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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