K
Neutral-current measuring relay
Measuring relay fed from a CT in a neutral conductor or star-point connection, responding to neutral current.
Schematic / SLD
IEEE / ANSI · K
ANSI/IEEE Neutral-current measuring relay form
IEEE-library form of neutral-current measuring relay: measuring relay fed from a CT in a neutral conductor or star-point connection, responding to neutral current.
In plain English
What does ANSI/IEEE Neutral-current measuring relay form mean?
This reference locates neutral-current measuring relay in Autodesk's IEEE-oriented current protection relays family. This relay form is used where a CT is installed in a neutral conductor or in the earthing connection of a transformer or generator star point. Current there indicates earth faults or, in four-wire systems, heavy unbalance and triplen harmonic loading, depending on where the CT sits. The public library uses HCR1F32 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number.
A simple example
Trace the measured quantity or initiating control signal separately from the output contacts. The device tag links the sensing or operating element to the controlled circuit; settings, reset behaviour and the actual terminal arrangement belong in the selected equipment documentation.
What the drawings help you do
The symbol identifies the measured conductor but not the purpose. A neutral CT in the star-point earth lead gives standby earth-fault protection, while one in the four-wire neutral of a feeder sees load unbalance as well, so settings and grading differ greatly. Confirm whether the CT is in the neutral conductor or the earthing lead. A neutral-current relay measures one neutral path; a residual connection sums the three phase CTs to derive the same quantity. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted.
This particular reference
IEEE-library form of neutral-current measuring relay: measuring relay fed from a CT in a neutral conductor or star-point connection, responding to neutral current. A neutral-current relay measures one neutral path; a residual connection sums the three phase CTs to derive the same quantity.
- Winding
- A coil of conductor inside an electrical machine or transformer.
- Normally open / normally closed
- The contact state in the normal condition defined for the drawing.
- Coil
- A wound conductor that can produce a magnetic field when energised.
Read the source: Autodesk IEEE Symbol Preview: Current Protection Relays · IEC graphical symbols for diagrams
IEEE / ANSI · In Neutral
Autodesk IEEE Symbol Preview: Current Protection Relays, block HCR1F32. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
Schematic / SLD · K
What it represents
This reference locates neutral-current measuring relay in Autodesk's IEEE-oriented current protection relays family. This relay form is used where a CT is installed in a neutral conductor or in the earthing connection of a transformer or generator star point. Current there indicates earth faults or, in four-wire systems, heavy unbalance and triplen harmonic loading, depending on where the CT sits. The public library uses HCR1F32 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number.
Trace the measured quantity or initiating control signal separately from the output contacts. The device tag links the sensing or operating element to the controlled circuit; settings, reset behaviour and the actual terminal arrangement belong in the selected equipment documentation.
The symbol identifies the measured conductor but not the purpose. A neutral CT in the star-point earth lead gives standby earth-fault protection, while one in the four-wire neutral of a feeder sees load unbalance as well, so settings and grading differ greatly. Confirm whether the CT is in the neutral conductor or the earthing lead. A neutral-current relay measures one neutral path; a residual connection sums the three phase CTs to derive the same quantity. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted.
How to read it
- Confirm whether the CT is in the neutral conductor or the earthing lead.
- Check grading against downstream earth-fault devices.
Information to show or reference
- Show neutral CT location
- State setting and delay
- Reference grading study
A distinction that matters
A neutral-current relay measures one neutral path; a residual connection sums the three phase CTs to derive the same quantity.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Autodesk IEEE Symbol Preview: Current Protection Relays
Public IEEE-oriented Current Protection Relays table explicitly lists HCR1F32 as In Neutral. This supports the vendor convention context, not reproduction of the publisher graphic.
IEC graphical symbols for diagrams
IEC context for graphical symbols used in diagrams; no IEC graphic is reproduced.
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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