BS EN 60079-17:2007 Explosive atmospheres. Electrical installations inspection and maintenance
Electrical installations in hazardous areas possess features specially designed to render them suitable for operations in such atmospheres. It is essential for reasons of safety in those areas that, throughout the life of such installations, the integrity of those special features is preserved; they therefore require initial inspection and either:
• Regular periodic inspections
• Continuous supervision by skilled personnel in accordance with this standard and, when necessary, maintenance.
Correct functional operation of hazardous area installations does not mean, and should not be interpreted as meaning, that the integrity of the special features referred to above is preserved.
BS EN 60079:17 applies to users and covers factors directly related to the inspection and maintenance of electrical installations within hazardous areas only, where the hazard may be caused by flammable gases, vapours, mists, dusts, fibres or flyings.
BSEN60079 Part 17 does not include:
• Other fundamental installation and inspection requirements for electrical installations
• The verification of electrical equipment
• The repair and reclamation of explosion protected equipment.
This standard supplements the requirements of IEC 60364-6.
In the case of dusts, fibres or flyings the level of housekeeping may influence the inspection and maintenance requirements.
BS EN 60079-17 is intended to be applied where there can be a risk due to the presence of explosive gas or dust mixtures with air or combustible dust layers under normal atmospheric conditions. It does not apply to:
• Underground mining areas
• Areas where a risk can arise due to the presence of hybrid mixtures
• Dusts of explosives that do not require atmospheric oxygen for combustion
• Pyrophoric substances.
The contents of BS EN 60079-17 includes:
• Normative references
• Terms and definitions
• General requirements
• Qualification of personnel
• Grades of inspection
• Types of inspection
• Periodic inspections
• Fixed installations
• Moveable equipment
• Continuous supervision by skilled personnel
• Frequency of inspection
• Maintenance requirements
• Remedial measures and alterations to equipment
• Maintenance of flexible cables
• Withdrawal from service
• Fastenings and tools
• Environmental conditions
• Isolation of equipment
• Installations other than intrinsically safe circuits
• Intrinsically safe installations
• Earthing and equipotential bonding
• Specific conditions of use
• Movable equipment and its connections
• Inspection schedules
• Equipment is appropriate to the EPL/zone requirements of the
• Equipment group is correct
• Equipment maximum surface temperature is correct
• Equipment circuit identification
• Cable gland
• Type of cable is appropriate
• Fault loop impedance or earthing resistance
• Insulation resistance
• Overload protection
• Additional inspection schedule requirements
• Type of protection "d" – Flameproof enclosure
• Flameproof joints
• Type of protection "e" – Increased safety
• Type of protection "i" and "iD" – Intrinsic safety
• Unauthorized modifications
• Associated apparatus (safety interface) between intrinsically safe and non-intrinsically safe circuits
• Cable screens
• Point-to-point connections
• Earth continuity of non-galvanically isolated circuits
• Earth connections to maintain the integrity of the intrinsic safety
• Intrinsically safe circuit earthing and/or insulation
• Separation between intrinsically safe and non-intrinsically safe
• Type of protection "p" and "pD" – Pressurized enclosure
• Type of protection "n"
• Restricted breathing enclosures
• Type of protection "tD" – Protection by enclosure
• Types of protection "m" and "mD" (encapsulation), "o" (oil-immersion) and "q" (powder-filling)
• Inspection schedules
• Typical inspection procedure for periodic inspections
• Knowledge, skills and competencies of "responsible persons", "technical persons with executive function" and "operatives"
• Introduction of an alternative risk assessment method
• encompassing “equipment protection levels” for Ex equipment
• Inspection schedule for Ex "d", Ex "e" and Ex "n" installations (D = Detailed, C = Close, V = Visual)
• Inspection schedule for Ex "i", "iD" and "nL" installations
• Inspection schedule for Ex "p" and "pD" installations
• Inspection schedule for Ex "tD" installations
• Traditional relationship of EPLs to zones (no additional risk assessment)
• Description of risk of ignition protection provided
• Normative references to international publications with their corresponding European publications
BS EN 60079-17:2007 replaces BS EN 60079-17:2003 and BS EN 61241-17:2005 which remain current.