Protective shroud for emergency-stops: Permitted or not? – standards, benefits and application

What are protective shrouds for emergency-stop buttons?

Protective shrouds are mechanical devices that prevent the unintentional activation of emergency-stop buttons.

Are protective shrouds on the emergency-stop permitted?

Yes – protective shrouds are permitted as long as they fulfil the requirements of DIN EN ISO 13850 and IEC 60204-1. 

The requirements for permissibility are:

• The function of the emergency-stop button may not be affected or impeded.
• Visibility and accessibility of the emergency-stop must be maintained.
• The installation must be done correctly.

The protective shroud for emergency-stop mushroom heads can be part of safety solution conforming to standard.

What do the applicable standards include?

The most important standards for protective shrouds and emergency-stop systems are:

• DIN EN ISO 13850: Functional safety of emergency-stop set-ups. This standard ensures that the emergency-stop function works reliably in a case of emergency and protect personnel from injuries. The Machinery Directive requires adherence to this norm to guarantee safety of machines.
• IEC 60204-1: Requirements for electrical equipment of machines.
• Machinery Directive 2006/42/EG: The legal basis for machine safety with mandatory compliance.

Manufacturer specifications, certificates and test certificates that should be consulted to prove the conformity to standards.

Benefits of using a protective shroud for emergency-stop buttons

• Prevents unintended activation, e.g. through tools, falling items or body contact
• Increases operational safety
• Can be retrofitted easily in most cases
• Maintains the functionality of the emergency-stop

Especially in production facilities and workshops, the use of a protective shroud proves to be a preventive safety measure.

What to consider during installation

Common mistakes are the use of an unsuitable protective shroud or an unintended activation of the emergency-stop button during installation.

Another important thing is the correct colour: For an emergency-stop, a red button on yellow background is compulsory according to the standard, thus the protective shroud has to be yellow as well. The emergency-stop button always has to be easily recognisable and accessible.

A final functional test after installation is mandatory. To avoid mistakes during the installation of a protective shroud, it is important to adhere to the manufacturer specifications.

SCHLEGEL protective shrouds: systematic safety

The SCHLEGEL protective shrouds are especially designed for industrial applications. They offer:

• A robust design
• Compatibility with SCHLEGEL’s emergency-stop series
• Modular expandability (e.g. with illumination)
• Easy installation 

Additional accessory

Apart from the actual protective shroud, there are many accessories that expand the functionality of the emergency-stop systems and devices. Those accessories contribute to adjust the emergency-stop buttons to the specific requirements of each machine.

Some examples for accessories are:

• Adapter rings to adjust to the various button sizes
• Sealing gaskets to protect against dust and humidity
• Labels to clearly marking the emergency-stop button
• Special covers to prevent unintended activation are also available as accessory
• Robust protective enclosure: to protect the emergency-stop button against mechanical damage
• LED illumination: to increase visibility of the emergency-stop mushroom head according to DIN EN ISO

Conclusion: permitted and useful addition

Protective shrouds are a permitted and useful addition for emergency-stop systems. They are an effective measure to improve machine safety, especially in environments with increased risk of unintended activation. With products like those of SCHLEGEL, safety requirements can be realised according to applicable standards and with practical orientation.