# ANSI/IEEE Frequency monitoring relay form Canonical URL: https://eloragrid.ai/symbols/ansi-frequency-monitoring-relay Publisher: Elora Grid Updated: 2026-10-28 Lookup label: f MON Drawing use: SLD, Schematic Reference families: IEEE / ANSI, Manufacturer ## Symbol convention Convention: IEEE / ANSI Form: Frequency Relay Autodesk IEEE Symbol Preview: Miscellaneous Relays, block HCR1F40. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier. Related representation: [Frequency monitoring relay](https://eloragrid.ai/symbols/frequency-monitoring-relay) IEEE-library form of frequency monitoring relay: a frequency relay issues a documented output for a configured frequency condition. ## In plain English ### What does ANSI/IEEE Frequency monitoring relay form mean? This reference locates frequency monitoring relay in Autodesk's IEEE-oriented miscellaneous relays family. A frequency relay issues a documented output for a configured frequency condition. The schematic identifies its measurement input and links its thresholds to the settings record. The public library uses HCR1F40 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 Determine whether high frequency, low frequency or both are monitored. A frequency relay applies operating criteria; a frequency meter only indicates the measured value. 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 frequency monitoring relay: a frequency relay issues a documented output for a configured frequency condition. A frequency relay applies operating criteria; a frequency meter only indicates the measured value. ### Terms - 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. - Terminal: An identified point where a conductor connects. Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram. - [Autodesk IEEE Symbol Preview: Miscellaneous Relays](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-DA549E3E-4ABB-426E-9331-0226EF55EAA7.htm) ## What it represents This reference locates frequency monitoring relay in Autodesk's IEEE-oriented miscellaneous relays family. A frequency relay issues a documented output for a configured frequency condition. The schematic identifies its measurement input and links its thresholds to the settings record. The public library uses HCR1F40 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. Determine whether high frequency, low frequency or both are monitored. A frequency relay applies operating criteria; a frequency meter only indicates the measured value. 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 - Determine whether high frequency, low frequency or both are monitored. - 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 - Name measured bus - Reference thresholds and delay - Show output contacts ## Important distinction A frequency relay applies operating criteria; a frequency meter only indicates the measured value. ## Facts - Convention evidence: Autodesk IEEE Symbol Preview: Miscellaneous Relays; published form: Frequency Relay. - Public vendor block: HCR1F40. Vendor library token, not an IEEE symbol number. - Drawing role: Monitoring element - Identifier status: The short label is a functional lookup label, not an assigned IEC or IEEE symbol number. Any separately listed Autodesk code is a verified vendor block name. - Artwork scope: Original educational geometry. Exact standard graphics, product ratings and terminal pinouts are not certified. ## Public references - [Autodesk IEEE Symbol Preview: Miscellaneous Relays](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-DA549E3E-4ABB-426E-9331-0226EF55EAA7.htm) — Autodesk. Public IEEE-oriented Miscellaneous Relays table explicitly lists HCR1F40 as Frequency Relay. This supports the vendor convention context, not reproduction of the publisher graphic. ## Graphic scope Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.