Underground » Health and Safety
This report is presented as an introductory text to investigate the basic aspects of the design and manufacture of intrinsically safe (IS) electronic instrumentation for use in Australian coalmines, and to provide practical guidelines to help smooth the path to obtain certification. The document serves as an instruction tool for the uninitiated, as well as catering for those who have some initial experience of IS design.
Future trends for mining equipment lean strongly in the direction of automation, autonomous vehicles, and remotely operated mining machinery. To assist individuals within the industry to prepare for these developments, it is timely to provide guidelines which help to clarify the design process for intrinsically safe electric circuits and to provide updated information and guidance on how to navigate the approval process.
It is not possible to cover every IS situation in a single text, so common design issues have been addressed in the belief that the reader will be able to successfully apply the techniques to related situations as they are encountered. The report maintains a focus on the current Australian Standards and references are made to the relevant standards throughout the text.
The early sections provide background information and discuss the fundamental issues relevant to intrinsic safety. Basic electrical concepts, the conditions for spark ignition, and the categories of IS equipment are defined. Section 3 deals with the practical aspects such as creepage, clearance, separation, safety factors, and general mechanical considerations while Section 4 expands upon these issues and looks in detail at IS battery design and the physical aspects of battery assemblies.
A complete section is devoted to associated apparatus and the basics of IS barrier design are discussed in some detail. Section 6 provides information on the definitions and origin of the entity parameters used to characterise IS electrical systems and Section 7 provides the necessary information to obtain new and supplementary IS certification in Queensland and New South Wales. To assist the reader, diagrams and practical examples are used throughout the report and appendices containing a broad range of relevant IS information are included.
Finally, for those readers who wish to manufacture an IS instrument and obtain certification, a list of the necessary Australian Standards is provided. As an adjunct, a comprehensive table of references designed to assist with the navigation of these standards is included in the appendices.