K
Earth-fault voltage relay
Relay form that operates on a voltage appearing because of an earth fault, such as between a frame and earth.
Schematic / SLD
IEEE / ANSI · K
ANSI/IEEE Earth-fault voltage relay form
IEEE-library form of earth-fault voltage relay: relay form that operates on a voltage appearing because of an earth fault, such as between a frame and earth.
In plain English
What does ANSI/IEEE Earth-fault voltage relay form mean?
This reference locates earth-fault voltage relay in Autodesk's IEEE-oriented voltage protection relays family. This relay measures a voltage that appears only when there is an earth fault, for example between exposed metalwork and a reference earth, or across a neutral earthing impedance. It is useful where earth-fault current is limited and a voltage is easier to detect than a current. The public library uses HCR1F31 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 does not say where the voltage is measured. A relay across a neutral earthing resistor and one connected between frame and auxiliary earth electrode have very different settings, so the measurement points must be drawn and labelled. Trace both measurement connections of the relay. An earth-fault voltage relay measures fault-related voltage; a residual voltage relay measures zero-sequence voltage from VT windings. 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 earth-fault voltage relay: relay form that operates on a voltage appearing because of an earth fault, such as between a frame and earth. An earth-fault voltage relay measures fault-related voltage; a residual voltage relay measures zero-sequence voltage from VT windings.
- 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: Voltage Protection Relays
IEEE / ANSI · Ground Failure Voltage Protection
Autodesk IEEE Symbol Preview: Voltage Protection Relays, block HCR1F31. 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 earth-fault voltage relay in Autodesk's IEEE-oriented voltage protection relays family. This relay measures a voltage that appears only when there is an earth fault, for example between exposed metalwork and a reference earth, or across a neutral earthing impedance. It is useful where earth-fault current is limited and a voltage is easier to detect than a current. The public library uses HCR1F31 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 does not say where the voltage is measured. A relay across a neutral earthing resistor and one connected between frame and auxiliary earth electrode have very different settings, so the measurement points must be drawn and labelled. Trace both measurement connections of the relay. An earth-fault voltage relay measures fault-related voltage; a residual voltage relay measures zero-sequence voltage from VT windings. 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
- Trace both measurement connections of the relay.
- Check the reference earth used by the relay.
Information to show or reference
- Show measurement points
- State threshold and delay
- Reference earthing arrangement
A distinction that matters
An earth-fault voltage relay measures fault-related voltage; a residual voltage relay measures zero-sequence voltage from VT windings.
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: Voltage Protection Relays
Public IEEE-oriented Voltage Protection Relays table explicitly lists HCR1F31 as Ground Failure Voltage Protection. This supports the vendor convention context, not reproduction of the publisher 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.
Explore related references
U RES
Residual-voltage monitoring relay
A residual-voltage relay responds to the specified residual-voltage measurement.
SLD / Schematic
K
Earth-fault current relay
Measuring relay form that operates on current flowing to earth, fed from a residual connection or core-balance CT.
Schematic / SLD
64
Ground detector protection
Identifies an earth or ground fault using the circuit arrangement specified for the device.
Protection functions
Put the reference into a drawing workflow.
Elora Grid helps electrical teams work with drawings, specifications and equipment information. Explore the drafting workflow or join the early-access waitlist.