# IEC timing-relay form: on/off delay Canonical URL: https://eloragrid.ai/symbols/iec-timing-relay-form-on-off-delay Publisher: Elora Grid Updated: 2026-10-28 Lookup label: KT Drawing use: Schematic Reference families: IEC, Manufacturer ## Symbol convention Convention: IEC Form: ON/OFF Delay Autodesk IEC-60617 Symbol Preview: Time Delay Relays, HCR1OOD / VCR1OOD. This identifies the publisher's library context; exact IEC graphics and database identities are not asserted. Timing-relay form form: ON/OFF Delay. ## In plain English ### What does IEC timing-relay form: on/off delay mean? A timing relay separates the initiating signal from the later change of an output contact. The contact state, delayed transition and reset condition are independent: a timer may have immediate contacts alongside delayed contacts under the same device tag. This entry identifies the on/off delay form in the publisher's IEC-context family. ### A simple example A control sequence may start an auxiliary before enabling the main load, or keep a fan running after a stop request. Trace supply, trigger and output separately, then draw a timing chart that includes what happens when the trigger ends before a delay has elapsed. Both operating and return transitions carry a delay. Show the two timing values and the condition that starts each interval. ### What the drawings help you do The symbol does not supply the time setting, retriggering rule or power-loss behaviour. A three-terminal timing form also needs its actual manufacturer terminal mapping; the vendor name alone does not define a universal pinout. ### This particular reference Timing-relay form form: ON/OFF Delay. This entry adds the on/off delay detail to the broader timing-relay form family. The symbol does not supply the time setting, retriggering rule or power-loss behaviour. A three-terminal timing form also needs its actual manufacturer terminal mapping; the vendor name alone does not define a universal pinout. ### 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. - [AutoCAD Electrical: Time-delay relays](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-DA927086-EEAF-48CB-B9B1-634A4B48C8C7.htm) ## What it represents A timing relay separates the initiating signal from the later change of an output contact. The contact state, delayed transition and reset condition are independent: a timer may have immediate contacts alongside delayed contacts under the same device tag. This entry identifies the on/off delay form in the publisher's IEC-context family. A control sequence may start an auxiliary before enabling the main load, or keep a fan running after a stop request. Trace supply, trigger and output separately, then draw a timing chart that includes what happens when the trigger ends before a delay has elapsed. Both operating and return transitions carry a delay. Show the two timing values and the condition that starts each interval. The symbol does not supply the time setting, retriggering rule or power-loss behaviour. A three-terminal timing form also needs its actual manufacturer terminal mapping; the vendor name alone does not define a universal pinout. ## How to read it - Both operating and return transitions carry a delay. Show the two timing values and the condition that starts each interval. - The symbol does not supply the time setting, retriggering rule or power-loss behaviour. A three-terminal timing form also needs its actual manufacturer terminal mapping; the vendor name alone does not define a universal pinout. ## Information to show or reference - Identify the initiating supply or control signal. - Label delayed and immediate output transitions separately. - Reference timing settings, reset conditions and the device timing chart. ## Important distinction This entry adds the on/off delay detail to the broader timing-relay form family. The symbol does not supply the time setting, retriggering rule or power-loss behaviour. A three-terminal timing form also needs its actual manufacturer terminal mapping; the vendor name alone does not define a universal pinout. ## Facts - Drawing form: ON/OFF Delay - Public vendor block names: HCR1OOD / VCR1OOD. Autodesk identifiers, not standards database IDs. - Drawing purpose: timing-relay form - Graphic scope: Independently authored educational illustration; not certified standard geometry, a terminal pinout or a product footprint. ## Public references - [AutoCAD Electrical: Time-delay relays](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-DA927086-EEAF-48CB-B9B1-634A4B48C8C7.htm) — Autodesk. Public Time Delay Relays table explicitly lists HCR1OOD / VCR1OOD with this operating or connection form. Vendor graphics are linked, not copied. ## 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.