Safe Handling, Operation and Maintenance of Electrical Equipment in Hazardous Areas and Classification

Introduction

Preventing the unintentional ignition of explosive atmospheres is a critical safety and economic aspect of all petroleum and chemical plant operations.

This course is intended to give:

• An in-depth understanding of hazardous areas from the initial nature of the problem
• Some case studies of industrial accidents, through the identification and classification of the hazard, selection, and use of protected equipment
• The administration of hazardous areas in terms of record-keeping and certificates

Objectives

By the end of this course participants will be able to:

• Provide a clear understanding of hazardous area current custom and practice with particular respect to the following:
• Define the hazard, classifying hazard materials, understanding the nature of the risk and the necessity to eliminate sources of ignition
• Identify and quantify the hazardous areas
• Select appropriate electrical equipment and instruments for those areas
• Recognize the different methods of protection Ex d Ex I etc. and how they work
• Install, inspect and maintain the certified equipment
• Understand the need for, and typical approach to, electrical equipment inspection

Target Audience

This course is a single and comprehensive training package which involves a combination of formal lectures, practical exercises, demonstrations, and written exercises.

It is primarily aimed at:

• Safety, electrical, instrumentation, and engineers or technicians

Occupational Health and Safety Outline

The course covers the following topics:

Introduction and History

• A brief history of Industrial fires and explosions
• Materials
• Understanding the important characteristics of hazardous materials and how they behave when they are ignited.
• Looking at the data tables and seeing how, Flashpoint, boiling point, etc. influence our approach to the materials.
• Area Classification
• A look at the techniques and the procedures that result in the formal allocations of zones zero, one and two
• Sources of Hazard, duration of release, the extent of zones, calculations, nature of the hazard and release characteristics

Area Classification

• Apparatus Groups and Temperature Classes
• How apparatus and hazard materials are matched together in terms of ignition energies, flame transmission characteristics and ignition temperatures.
• Source of Ignition
• A look at some of the possible sources of ignition, e.g. static electricity, light metal thermite reactions, friction, etc., which can occur in hazardous areas. Also consider some of the steps which can be taken to eliminate them
• Methods of Protection
• Considering the recognized methods of protection. The fundamental concept in each case and the zones in which they may be employed
• Flameproof
• Intrinsic Safety
• Increased Safety
• Pressurized 
• A written exercise in which the relationship between zones, Apparatus groups, temperature classes and certifies electrical equipment is examined
• Flameproof
• Considering in depth the concept of Flameproof protection, how it works, how it must be installed, how it must be inspected and maintained. Looking at weatherproofing, corrosion, gaps, fasteners, etc

Equipment Inspection

• Examining samples and answering questions about them
• Intrinsic Safety
• As for flameproof, an in-depth look at the subject considering minimum ignition energies, associated apparatus, and systems, simple apparatus, IS clean earth, floating systems, system matching, etc
• Intrinsic Safety Installation
• Segregation of cables, screens, and armor, earthing and bonding, induction and invasion, creepage and clearance etc
• Increased Safety
• An in-depth look at this concept of protection making comparisons with flameproof, and stressing the vital importance of correct installation. Also looking at weatherproofing rating, stoppers, and bolts, derating, etc.

Pressurised Apparatus

• A close examination of this method of protection, what it can be applied to, when certification is possible and how to maintain it. Where pressurized rooms fit in and how uncertified pressurized enclosures may be used
• A thorough examination of type N considering non-sparking, enclosed break, energy limitation, and restricted breathing concepts. Also making comparisons with the concepts of protection already covered in detail
• The Less Common Types of Protection
• Equipment Inspection
• Labels, Marking and Certificates
• A look at the codings, certificate numbers, and other essential markings on labels and certificates. Including a paper exercise to identify equipment and assess its suitability for a given environment

Installation, Inspection, and Maintenance

• Considering the guidance of National codes of practice in terms of wiring and cabling, identification, isolation, inspections and maintenance and Cable entries
• Considering cable and conduit entries to all types of enclosures and protection concepts. Also looking at adapters and reducers, plugs and correct selection in each circumstance
• Equipment Inspection Exercise Final session
• Legislation
• What the Law has to say, standards, certificates, codes, European directives, the HSE and how it all ties together
• Administration and Record-Keeping
• Considering the records that should be kept by a company in order to manage a hazardous area installation