Isolator
Disconnector
A switching device providing an electrical isolation function.
SLD / Schematic
Symbols · LBS
Load-break switch
A switch with a specified capability to make and break normal load current.
SLD / Schematic · LBS
What it represents
A load-break switch operates a loaded circuit under the normal conditions covered by its rating. It should not be confused with a circuit breaker, whose specified duties can include interrupting fault current. Some products combine switching and isolation, and some are used with fuses for a protection arrangement.
The SLD shows where the switch connects the circuit. Its schedule or manufacturer reference establishes the duty and capabilities. The device name, qualifiers and associated protective equipment explain more than the generic mark alone.
How to read it
- Look for a separately identified fuse or breaker in the protection path.
- Check whether isolation is an additional specified function of the chosen product.
Information to show or reference
- Reference the load-switching capability.
- Identify any associated protection device.
- Record the product type and operating arrangement.
A distinction that matters
Fault-making, load-breaking and fault-breaking are different capabilities. Avoid using a single switch label as a substitute for the equipment specification.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Elementary switching devices
Public explanation of load-break switches and their relationship to protection.
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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