PB NO
Normally open pushbutton
A pushbutton contact normally shown open before actuation.
Schematic
IEC · PB
IEC pushbutton contact: mushroom head normally open twist latch
Pushbutton contact form: Mushroom Head Normally Open Twist Latch.
In plain English
What does IEC pushbutton contact: mushroom head normally open twist latch mean?
A pushbutton translates a person pressing an operator into a change of electrical contact state. The operator form and the contact state are separate pieces of information, so a mushroom head can operate either a normally-open or a normally-closed contact. This entry identifies the mushroom head normally open twist latch form in the publisher's IEC-context family.
A simple example
On a machine control sheet, this form lets the reader distinguish the physical button action from the contact used by the controller. Link every contact block to the same operator tag, including a separate indication lamp when fitted. The normally-open designation starts with a non-conducting output or open contact in the documented reference condition; operation changes that state. The operator is mechanically retained and uses a twist-release action; clearing the mechanical latch and restarting the machine are separate actions.
What the drawings help you do
The head shape and contact drawing do not establish a safety category, contact rating or emergency-stop suitability. Direct opening, reset behaviour and the selected assembly must be confirmed from its documentation.
This particular reference
Pushbutton contact form: Mushroom Head Normally Open Twist Latch. This entry adds the mushroom head normally open twist latch detail to the broader pushbutton contact family. The head shape and contact drawing do not establish a safety category, contact rating or emergency-stop suitability. Direct opening, reset behaviour and the selected assembly must be confirmed from its documentation.
- Normally open / normally closed
- The contact state in the normal condition defined for the drawing.
- Signal
- Electrical information passed between devices, rather than necessarily the main power supply.
- Rating
- A value stating the conditions for which equipment is specified.
Read the source: Pushbutton contact and actuator variants
IEC · Mushroom Head Normally Open Twist Latch
Autodesk IEC-60617 Symbol Preview: Push Buttons, HPB11MTL / VPB11MTL. This identifies the publisher's library context; exact IEC graphics and database identities are not asserted.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
Schematic · PB
What it represents
A pushbutton translates a person pressing an operator into a change of electrical contact state. The operator form and the contact state are separate pieces of information, so a mushroom head can operate either a normally-open or a normally-closed contact. This entry identifies the mushroom head normally open twist latch form in the publisher's IEC-context family.
On a machine control sheet, this form lets the reader distinguish the physical button action from the contact used by the controller. Link every contact block to the same operator tag, including a separate indication lamp when fitted. The normally-open designation starts with a non-conducting output or open contact in the documented reference condition; operation changes that state. The operator is mechanically retained and uses a twist-release action; clearing the mechanical latch and restarting the machine are separate actions.
The head shape and contact drawing do not establish a safety category, contact rating or emergency-stop suitability. Direct opening, reset behaviour and the selected assembly must be confirmed from its documentation.
How to read it
- The normally-open designation starts with a non-conducting output or open contact in the documented reference condition; operation changes that state.
- The operator is mechanically retained and uses a twist-release action; clearing the mechanical latch and restarting the machine are separate actions.
- The head shape and contact drawing do not establish a safety category, contact rating or emergency-stop suitability. Direct opening, reset behaviour and the selected assembly must be confirmed from its documentation.
Information to show or reference
- Identify the operator and each associated contact block.
- State the contact state before the operator is pressed.
- Show the release or return action and any independent lamp supply.
A distinction that matters
This entry adds the mushroom head normally open twist latch detail to the broader pushbutton contact family. The head shape and contact drawing do not establish a safety category, contact rating or emergency-stop suitability. Direct opening, reset behaviour and the selected assembly must be confirmed from its documentation.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Pushbutton contact and actuator variants
Public Push Buttons table explicitly lists HPB11MTL / VPB11MTL with this operating or connection form. Vendor graphics are linked, not copied.
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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