Electrical Construction – What you need to know
Electrical units of measurement
What are the electrical units of measurement associated with in-service inspection and testing of electrical equipment?
Equipment Construction Classes and Methods of Protection
In the UK, equipment construction classes and methods of protection are governed by standards such as BS EN 60079 and the Electrical Equipment (Safety) Regulations 2016. These define how electrical equipment is designed to ensure safety, especially in hazardous environments.
Equipment Construction Classes
Classes define how electrical equipment is constructed to protect users from electric shock, the graphics below provide examples of the protection offered by each class ad examples of what each may be.
Class I Equipment
Class II Equipment
Class III Equipment
Methods of Protection in Hazardous Areas (ATEX/UKEX)
The methods of protection are detailed in BS EN 60079 Parts 0–20, which cover general requirements, specific protection types, and area classifications.
In potentially explosive atmospheres (e.g., oil refineries, flour mills), the UK follows BS EN 60079 series standards, aligned with ATEX and UKEX regulations:
The UK Regulatory Framework
Electrical Equipment (Safety) Regulations 2016
- Applies to all electrical equipment sold in Great Britain
- Requires CE or UKCA marking and conformity with essential safety requirements
- Covers voltage ranges: 50–1000V AC and 75–1500V DC
HSE Guidance
- The Health and Safety Executive (HSE) provides detailed guidance on selecting and maintaining equipment in explosive atmospheres
- Emphasises compliance with UKEX (post-Brexit equivalent of ATEX) and BS EN 60079 standards