GEN
Generator
An electrical generating source represented in a power-system drawing.
SLD / Schematic
Protection functions · 78
Phase-angle or out-of-step protection
Supervises the angular relationship or loss of synchronism of an electrical system or machine.
SLD / Schematic · 78
What it represents
Supervises the angular relationship or loss of synchronism of an electrical system or machine.
In a drafting package, connect this reference to the voltage/current measurement references and protected machine. The associated drawing should trace the out-of-step trip, separation or blocking outputs; the number identifies the role and does not specify the terminal arrangement, ratings or operating settings.
How to read it
- Identify the voltage/current measurement references and protected machine.
- Trace the out-of-step trip, separation or blocking outputs.
Information to show or reference
- Label the voltage/current measurement references and protected machine.
- Cross-reference the out-of-step trip, separation or blocking outputs.
- Identify the device tag, manual revision and logic drawing that define this implementation.
A distinction that matters
Out-of-step protection during operation is distinct from a 25 closing-permission synchronism check.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
ANSI device-number and suffix reference table
Public manufacturer number/name association. Drafting explanations are independently written.
IEEE C37.2-2022: power-system device function numbers
Normative device-number publication; exact edition wording and compliance require the licensed standard.
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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