Control and Signalling
The surface where the operator meets the machine: pushbuttons, pilot lights, emergency stops and crane pendants.
Pushbuttons, boxes, crane pendants
6sub-categories
For control devices, IP rating, contact configuration and the safety level required for emergency stops are decisive. Weiller pushbuttons and enclosures, Eurowest button ranges and Omron contact blocks cover both standard panel-front applications and harsh field conditions. For crane pendants we also assess suspension load and cable strain relief.
What this group covers
- Pushbuttons and pilot lights
- Emergency stop buttons
- Pushbutton enclosures
- Crane pendant controls
- Cam switches
- Contact blocks
How to choose the right product in this group
These are the same criteria we check when preparing a quotation. Send us your list and we run these checks on your behalf.
- 01
Protection class and environment
Panel-front devices and field pushbutton enclosures are not the same. Washdown, oil mist and impact risk determine the protection class.
- 02
Contact configuration
The number of NO/NC contacts must be fixed up front. Emergency stop applications require positively opening contacts.
- 03
Suspension load for crane pendants
The pendant's weight must not hang on the cable; a support cord and the cable's strain relief are calculated separately.
- 04
Head diameter and cut-out size
22 mm is the standard cut-out for industrial pushbuttons, with 16 and 30 mm bodies also in use. When adding to an existing panel, confirm the cut-out first: otherwise the door has to be re-drilled and the protection class drops.
The mistakes we meet most often on site
- Using a standard NC contact for emergency stop and never detecting a welded contact.
- Mounting a pushbutton enclosure outdoors without checking its protection class.
- Ordering pilot lights without confirming the voltage.
- Running a pendant cable with no support cord.
Terms you will meet in quotations and specifications
The concepts that come up most often in correspondence about this group, with short definitions.
- Positive opening
- A construction in which the contact is mechanically forced open. It is mandatory for emergency stop applications.
- NO / NC contact
- Normally open and normally closed contacts; the control logic is built from their combination.
- Contact block
- A module fitted behind the operator head to increase the number of contacts.
- Pendant speed stage
- A two-stage arrangement that selects speed according to how far the button is pressed.
Frequently asked about Control and Signalling
Which contact does an emergency stop need?
A positively opening NC contact is used, preferably wired dual-channel. Evaluation should be done by a safety relay or safety PLC.
Can I buy the pushbutton box pre-wired?
Yes. Send the layout of buttons, pilot lights and emergency stop and we can deliver the box drilled, assembled and terminated. Labelling is done on request.
How many buttons should a crane pendant have?
It follows the number of motions: four buttons usually suffice for a single-speed hoist, while double-speed overhead cranes use six to eight two-stage buttons. An emergency stop is always a separate element.
Should pilot lights be LED?
Yes, LED types last far longer and draw less current. On PLC outputs, though, leakage current can keep an LED faintly lit; a bleeder resistor solves it.
Where should the emergency stop be placed?
Where the operator can reach it easily in an emergency: unobstructed and visible. On large machines each operator station and access point needs its own emergency stop, all wired into the same safety circuit.
Explore the other groups
- SwitchgearProtection, switching and control
- Industrial AutomationPLC, drives, servo, robotics
- Cable and ConnectionPower, control, terminals, termination
- Enclosures and PanelsSheet-steel enclosures, busbars, climate control
- Cable ManagementTrunking, conduit, spiral wrap
- Tools and ConsumablesCrimping, cutting, marking
Have a project or a material list?
Send us your list; we return stock status, lead time and wholesale pricing the same day.