# Time switch plan mark

Canonical URL: https://eloragrid.ai/symbols/iec-time-switch-plan-mark
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: TSW
Drawing use: GA
Reference families: IEC

## Symbol convention

Convention: IEC
Form: Time switch
IEC 60617 installation-plan style (architectural and topographical installation symbols); independently drawn, not certified IEC geometry or a database identifier.

Plan mark for a clock-operated time switch that switches a circuit on a programmed schedule.

## In plain English

### What does Time switch plan mark mean?

A time switch operates a contact according to a daily, weekly or astronomical program. Plans draw a clock face, a circle with hands, combined with a switch stroke or placed in the board, and link it to the controlled circuit such as external lighting or a water heater.

### A simple example

Time switches are often mounted in the distribution board on a DIN rail; in that case the plan mark may appear in the board schedule rather than on the floor plan. Where local, it is drawn at the wall. The mark does not state the program, the number of channels or the reserve battery. Those are specified.

### What the drawings help you do

Check whether it is board-mounted or local. Look for an associated photocell. A time-delay push switch runs for a fixed period after a press; a time switch follows a clock schedule.

### This particular reference

Plan mark for a clock-operated time switch that switches a circuit on a programmed schedule. A time-delay push switch runs for a fixed period after a press; a time switch follows a clock schedule.

### Terms

- Normally open / normally closed: The contact state in the normal condition defined for the drawing.
- Schematic: A drawing showing function and connections rather than physical appearance.

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.

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/)
- [AutoCAD Electrical: Instrumentation and sensors](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-773A36C3-44C6-43EB-9BD0-E0297816B9B2.htm)


## What it represents

A time switch operates a contact according to a daily, weekly or astronomical program. Plans draw a clock face, a circle with hands, combined with a switch stroke or placed in the board, and link it to the controlled circuit such as external lighting or a water heater.
Time switches are often mounted in the distribution board on a DIN rail; in that case the plan mark may appear in the board schedule rather than on the floor plan. Where local, it is drawn at the wall. The mark does not state the program, the number of channels or the reserve battery. Those are specified.

## How to read it

- Check whether it is board-mounted or local.
- Look for an associated photocell.

## Information to show or reference

- State channels and program type.
- Link to controlled circuits.
- Note contactor if load is large.

## Important distinction

A time-delay push switch runs for a fixed period after a press; a time switch follows a clock schedule.

## Facts

- Graphic cue: Clock face with switch stroke
- Program types: Daily, weekly or astronomical
- Exact standard graphic: Not reproduced here; confirm the form against IEC 60617 and the project legend

## Public references

- [IEC graphical symbols for diagrams](https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/) — IEC. IEC graphical symbol context; independently drawn here.
- [AutoCAD Electrical: Instrumentation and sensors](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-773A36C3-44C6-43EB-9BD0-E0297816B9B2.htm) — Autodesk. Public IEC-oriented family that includes a clock indication form.

## 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.