BS EN IEC 60947-5-8:2021

What is BS EN IEC 60947-5-8 about? 

BS EN IEC 60947-5-8 specify the requirements for three-position enabling switches. These switches are used as components of enabling devices to provide signals that, when activated, allow machine operation to be initiated by a separate start control, and  when de-activated, initiate a stop function, and prevent initiation of machine operation. 

BS EN IEC 60947-5-8 does not deal with enabling device, these switches are intended to be connected to circuits which rated voltage does not exceed 250 V AC 50 Hz/60 Hz or 300 V DC. 

BS EN IEC 60947-5-8 does not apply to: 

• Three-position enabling switches for non-electrical control circuits, for example hydraulic, pneumatic; 
• Enabling switches without three-position mechanism; 
• Emergency stop devices 

Who is BS EN IEC 60947-5-8 for? 

BS EN IEC 60947-5-8 on three-position enabling switches is relevant to: 

• Manufactures of control circuit devices and switching elements such as three-position enabling switches 
• Companies dealing with setting up electrical power systems 
• Electrical design engineers 
• Test houses 
• Stockists 

Why should you use BS EN IEC 60947-5-8? 

Switchgear and control gear are widely used in electric utility transmission and distribution systems that are used to activate, de-energize, protect and assess defects in electrical equipment. In this regard, circuit control devices such as three-position enabling switches, are used to “turn on” and “turn off” current flow in an electrical circuit.  

BS EN IEC 60947-5-8 helps you manufacture the three position enabling switches for given voltages and switchgears to ensure an efficient electric system and safe usage across applications. 

BS EN IEC 60947-5-8 also provides you with additional protective measures to be taken with regards to moisture, corrosive atmosphere, UV radiation, which will help avoid and prevent damage to the three-position enabling switches. 

In the event a live circuit becomes hazardous, switching elements can arms operators with functional control to de-energize a part of the system or equipment.  

As a buyer of BS EN IEC 60947-5-8, you will be able to establish a safe and reliable electric supply system in commercial or industrial facilities of varied sizes. In industries such as robotics and automation that are heavily-dependent on efficient interaction between humans and machine, the three-position enabling switch can be vital in maintaining an advanced system for businesses. Efficient switching elements such as three-position enabling switches, will help eliminate damage to the equipment or personnel, especially when working in dangerous areas. Overall, adopting the global safety standards defined in BS EN IEC 60947-5-8, can instill credibility and acceptance for your business.  

What’s changed since the last update? 

BS EN IEC 60947-5-8:2021 supersedes BS EN 60947‑5‑8:2006, which is withdrawn. 

BS EN IEC 60947-5-8:2021 changes include: 

• Due to increasing range of useful applications of three-position enabling switches, note of scope, operational characteristics and tests are reviewed. 
• Figures for example of devices incorporating enabling switch are added in Annex A 
• New Annex B for procedure to determine reliability data for the switch used in functional safety applications is added