Currently, the use of electrical equipment in underground coal mines is covered under Canadian Standards Association (CSA) M421-93 "Use of Electricity in Mines" which makes reference to the Canadian Electrical Code and lists the specific requirements for the use of electrical equipment. Canadian underground coal mine regulations, including the CSA codes, do not currently address the issue of Hazardous Location Zoning for electrical equipment. Certification of electrical equipment is done by Natural Resources Canada and is universally accepted across the country.
Recent developments in the control of the potential hazard of the use of electrical equipment in underground coal mines could allow electrical equipment to be restricted according to hazardous location zoning requirements. This is the method being increasingly used in both Europe and the U.S.A.
A review of the Nova Scotia and Federal regulations governing the use of electrical equipment in underground coal mines is currently underway. Several working groups were created and are discussing a series of changes, which involve the concept of "Electrical Equipment Zoning" and proposals for designating "Low Explosion Risk Zones in Coal Mines". This could allow for the approval of equipment with less stringent forms of protection, whilst those areas designated as "High Risk Zones" would continue to require more stringent forms of protection, including: flameproof enclosures, intrinsic safety protection, increased safety, pressurisation, oil emersion and powder filling.
This project will therefore review recent developments in the control of the potential ignition hazard of use of electrical equipment in underground coal mines and will attempt to build on the experience already obtained. An appropriate approach will be recommended for consideration by regulators for Canadian mines. A letter was sent to HRDC - Labour Program explaining that the UCMSRC cannot support the zoning proposal as written, at this time, without further research.