K
Neutral-unbalance relay between two polyphase systems
Relay form measuring current in a link joining the star points of two polyphase systems, such as split capacitor banks.
Schematic / SLD
IEEE / ANSI · K
ANSI/IEEE Neutral-unbalance relay between two polyphase systems form
IEEE-library reference for neutral-unbalance relay between two polyphase systems, with its operating meaning, connection notes and public vendor block identity.
In plain English
What does ANSI/IEEE Neutral-unbalance relay between two polyphase systems form mean?
This reference locates neutral-unbalance relay between two polyphase systems in Autodesk's IEEE-oriented current protection relays family. This form shows a current relay in the conductor that joins the neutral points of two star-connected polyphase systems. A familiar application is the double-star capacitor bank, where a CT in the link between the two star points detects unbalance caused by failed capacitor units. The public library uses HCR1F33 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
In a healthy balanced arrangement the link carries little current, so the relay setting is a small fraction of phase current and must allow for natural unbalance. The symbol does not tell you the alarm and trip stages or the compensation for inherent unbalance; those are in the bank protection settings. Identify the two star points joined by the measured link. This relay measures the link between two star points; a neutral-current relay measures one neutral path to earth or to the supply. 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 reference for neutral-unbalance relay between two polyphase systems, with its operating meaning, connection notes and public vendor block identity. This relay measures the link between two star points; a neutral-current relay measures one neutral path to earth or to the supply.
- 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.
- Phase
- One of the related AC waveforms in a power system.
Read the source: Autodesk IEEE Symbol Preview: Current Protection Relays · IEC graphical symbols for diagrams
IEEE / ANSI · In Neutral between 2 Multi-Phase Systems
Autodesk IEEE Symbol Preview: Current Protection Relays, block HCR1F33. 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-unbalance relay between two polyphase systems in Autodesk's IEEE-oriented current protection relays family. This form shows a current relay in the conductor that joins the neutral points of two star-connected polyphase systems. A familiar application is the double-star capacitor bank, where a CT in the link between the two star points detects unbalance caused by failed capacitor units. The public library uses HCR1F33 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.
In a healthy balanced arrangement the link carries little current, so the relay setting is a small fraction of phase current and must allow for natural unbalance. The symbol does not tell you the alarm and trip stages or the compensation for inherent unbalance; those are in the bank protection settings. Identify the two star points joined by the measured link. This relay measures the link between two star points; a neutral-current relay measures one neutral path to earth or to the supply. 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
- Identify the two star points joined by the measured link.
- Look for separate alarm and trip stages.
Information to show or reference
- Show the interconnecting link and CT
- State alarm and trip settings
- Note inherent unbalance compensation
A distinction that matters
This relay measures the link between two star points; a neutral-current relay measures one neutral path to earth or to the supply.
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 HCR1F33 as In Neutral between 2 Multi-Phase Systems. 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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