CT
Current transformer
A current-measurement transformer used with metering and protection equipment.
SLD / Schematic
Symbols · I DIFF
Differential-current measuring relay
A differential-current relay responds to the relationship between specified current inputs.
SLD / Schematic · I DIFF
What it represents
A differential-current relay responds to the relationship between specified current inputs. The schematic must identify input directions, ratio matching and the protected or monitored zone.
How to read it
- Follow polarity and reference directions on all compared current circuits.
- The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation.
Information to show or reference
- Identify compared inputs
- Show polarity references
- Link setting and zone documentation
A distinction that matters
Differential measurement is not simply a single high-current threshold.
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: Current monitoring relays
Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic.
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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