TON
On-delay timer relay
An on-delay timer postpones a specified output transition after its timing condition becomes active.
Schematic
IEC · ST
Time-delay push switch plan mark
Plan mark for a push switch that turns lights on for a set period, commonly used in stairwells and common corridors.
In plain English
What does Time-delay push switch plan mark mean?
A time-delay push switch, often wired to a staircase timer, turns lighting on when pressed and lets it switch off after a set interval. Plans draw a push-button mark at each push position with a small clock or t tag, and show the timer location in the board where one is used.
A simple example
Several push switches may be wired in parallel to one timer, so the switching line links them all to a common luminaire group. The electrician reads the plan to run a separate push conductor rather than switched-line wiring.
What the drawings help you do
The plan symbol does not set the delay period or state whether the timer is in the switch or at the board. The specification should give both.
This particular reference
Plan mark for a push switch that turns lights on for a set period, commonly used in stairwells and common corridors. A momentary bell push is not connected to lighting; a time-delay push switch starts a lighting timer.
- Terminal
- An identified point where a conductor connects.
- Schematic
- A drawing showing function and connections rather than physical appearance.
Read the source: IEC graphical symbols for diagrams · Elementary switching devices
IEC · Time-delay push switch
IEC 60617 installation-plan style (architectural and topographical installation symbols); independently drawn, not certified IEC geometry or a database identifier.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
GA · ST
What it represents
A time-delay push switch, often wired to a staircase timer, turns lighting on when pressed and lets it switch off after a set interval. Plans draw a push-button mark at each push position with a small clock or t tag, and show the timer location in the board where one is used.
Several push switches may be wired in parallel to one timer, so the switching line links them all to a common luminaire group. The electrician reads the plan to run a separate push conductor rather than switched-line wiring.
The plan symbol does not set the delay period or state whether the timer is in the switch or at the board. The specification should give both.
How to read it
- Look for the associated timer in the board schedule.
- Expect several pushes wired in parallel on one landing group.
Information to show or reference
- State delay time and adjustment range.
- Show the timer location.
- Link all pushes to the controlled group.
A distinction that matters
A momentary bell push is not connected to lighting; a time-delay push switch starts a lighting timer.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
IEC graphical symbols for diagrams
IEC graphical symbol context; independently drawn here.
Elementary switching devices
Context for functional control switching.
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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