Quick Links
Choosing The Right Push button & Pilot Light Colours For Your Equipment Interface
As a business owner, you might be more comfortable in a boardroom analysing your company's performance. But place yourself in front of one of an industrial machine, and you will probably find everything disconcerting. Given the different HMI screens, push buttons of all colours, and the various indicator lights flashing across the control panel, the interface can seem like a Christmas tree.
So imagine the task of selecting the most suitable explosion-proof push button switches and indicator lights (pilot lights) for your machinery falling into your laps; it can be a real headache. You would probably be thinking, “Am I selecting the correct colours for the appropriate functions?”. Fortunately, you do not have to go at this alone. Let us help simplify the selection process by sharing how you can choose the correct push button switch and light indicator colours for your machine interfaces.
Understanding the colour coding for push button switches and indicator (pilot) lights
While the various colours can seem overwhelming initially, everything is relatively straightforward once you understand the logic behind the colour coding for your explosion-proof push button switches and indicator lights. The colours and the way the switches are displayed are actually homogeneous, and they must adhere to the IEC 60073 standard, which defines the coding principles for indicators and control elements.
The IEC 60073 standard deals only with the following colours: red, yellow, green, blue, white, grey, and black. And these colours are primarily used to indicate the action, whereas the flashes are meant to attract the user’s attention. Therefore, they must be used consistently to prevent any confusion. Keep this in mind, and the selection process becomes much more manageable. So without further ado, here are the main functions to consider:
- Emergency actuators
Emergency stop/off actuators must be identified with the colour red. Exceptions may be allowed if the colour is unavailable. But in such instances, there must be another reliable way for workers to identify the emergency push button. The same holds true if the switch is being used for both emergency and normal stop/off operations.
- Stop/off actuators
White, grey, and black are often the reference colours for stop/off push buttons. The general preference is usually black, and red is also allowed. However, avoid green, as it is forbidden.
- Start/on actuators
Source: https://thepihut.com/products/16mm-illuminated-pushbutton-green-momentary
White, grey, and black are the preferred colours for start/on actuators, similar to stop/off actuators. However, there is a preference for white for this explosion-proof push button switch. Green is also permitted. Meanwhile, never use red. When white and black are used for both start/on and stop/off pushbutton switches, white must be used for start/on actuators, and black must be used for the stop/off switches.
- Reset actuators
Reset actuators, which are used with protection relays usually, must be either blue, white, grey, or black. However, if the reset push button is also serving as the stop/off switch, it must be white, grey, or black.
- Indicator lights
When selecting the correct colours for your explosion-proof indicator lights, you can follow the same colour code, as it is identical to that of explosion-proof push button switches. Generally, neutral white is used when there are difficulties in assigning an appropriate colour. Crucially, the colour red used in emergency stop/off applications must be assigned to the actuator itself and not to its lighting.
We hope what we shared has provided you with a better understanding of the appropriate push button switch and indicator light colours for specific functions of your machine interfaces. Alternatively, please speak to our experts at Supermec if you require further assistance with the selection process.
At Supermec, we offer a wide range of explosion-proof light switches, push button switches, and indicator lights tailored for any business need. Do not hesitate to contact us, and our team will be glad to assist you.
Learn More: What is Explosion Proof (Ex-Proof)?
Back