R
Resistor
A resistive component with its value and purpose documented separately.
Schematic
Protection functions · 73
Load-resistor contactor
Switches a resistor used to impose, remove or change electrical load in a machine arrangement.
SLD / Schematic · 73
What it represents
Switches a resistor used to impose, remove or change electrical load in a machine arrangement.
In a drafting package, connect this reference to the load resistor and switched power connection. The associated drawing should trace the contactor control and resistor duty references; the number identifies the role and does not specify the terminal arrangement, ratings or operating settings.
This designation is useful when reading machine and legacy control drawings. Retain the documented function on an existing drawing and consult the original equipment manual before assigning it to a new design.
How to read it
- Identify the load resistor and switched power connection.
- Trace the contactor control and resistor duty references.
Information to show or reference
- Label the load resistor and switched power connection.
- Cross-reference the contactor control and resistor duty references.
- Identify the device tag, manual revision and logic drawing that define this implementation.
A distinction that matters
A load-resistor contactor switches the resistor circuit; the resistor's rating and ventilation remain separate design data.
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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