The New South Wales Department of Mineral Resources (DMR) is moving away from approving explosion protected electrical equipment (Ex equipment) for use in hazardous zones in underground coal mines, effectively transferring the duty of care to the equipment manufacturer, supplier and end-user. In future Ex equipment will be required to adhere to a certification program based on Australian and international standards.
The DMR currently approves how Ex equipment is used in NSW underground coal mine hazardous zones, but sees this as being at odds with contemporary occupational health and safety legislation which places responsibility with the organisations that create the safety risk; in other words, the manufacturers and mine operators.
To facilitate this move, a gazette notice was published by the DMR in 2003 which stated that if Ex equipment had an AUS Ex or ANZ Ex certificate of conformity (Ex CoC), or an IEC Ex CoC issued by an Australian Certification Body, then it was considered to be approved. This meant that there was no requirement to apply to the DMR for approval.
Importantly, the move brought NSW in line with the Queensland coal mining industry, which went down this path in 1994. The move away from the DMR approving Ex equipment is not new and has been occurring for well over ten years, beginning with the introduction of the Accredited Assessing Authority program in late 1991. It continued in 1999 with the promulgation of the Coal Mines Regulations 1999.
That year approval of portable electrical apparatus, mobile machines, earth leakage devices, earth fault lockout devices and earth continuity devices all ceased. It was at this time that certification became a requirement before approval would be granted for new Ex equipment.
It is expected that the legislation currently being developed in NSW and due for implementation in 2005 will maintain the requirement that Ex equipment be certified and provide for the continued use of currently approved equipment. While the DMR aims for all Ex equipment in NSW to have a CoC by 2010, it acknowledges this will be difficult to achieve. There are approximately 5000 types of equipment listed in the DMR approvals database, some of which cover 30-year-old equipment probably no longer in use.
There are some important points operators need to understand, said DMR senior inspector of electrical engineering, John Waudby.
An Ex CoC does not mean that the apparatus is fit for purpose for all elements of electrical engineering safety. An Ex CoC only covers the design, modification and verification parts of the life cycle and does not deal with environmental and site specific issues. Establishing whether an item is fit for purpose has to be done through risk assessment.
“Of particular importance is the risk assessment -- remember a risk assessment that determines apparatus is suitable for use in one situation does not mean it is automatically suitable in another situation. Mining method and work environment will play a critical role in this area. The mine has prime responsibility to establish what can be used where,” Waudby said.
An important question from a mine’s point of view is the effect of the gazette notice on existing approvals, but Waudby said the notice does not apply to approved equipment.
“Approval is pre-eminent. If equipment has an approval and a CoC – the approval conditions must be complied with.”
If the approved equipment has no Ex CoC then an Accredited Assessing Authority can assess supplementary approval for minor modifications only, but this option will only be available until the end of calendar 2004. After this date, if modifications are made to equipment with an earlier approval a CoC will have to be obtained.
Another development is the DMR has recently gazetted that workshops that repair Ex equipment are considered approved if certified to AS/NZS 3800 Electrical Equipment for Explosive Atmospheres - Overhaul and Repair, by a JAS-ANZ (Joint Accreditation System of Australia and New Zealand) accredited certification body, or by NATA (National Association of Testing Authorities, Australia) under its inspection program. This is the first step in moving from DMR approval to national recognition of Ex repair workshops.
This will have a positive flow-on effect in that it will mean equipment can be repaired by a certified workshop in Queensland for a mine in NSW, which will be particularly beneficial for companies transferring equipment interstate.
“The transition from approval to certification will mean many things and raise many issues for different sectors of the industry.” Waudby said.
“However, from a holistic perspective certification in lieu of approval is just about achieving the same objective in a different way; that is, electrical equipment used in hazardous zones is designed, tested, overhauled and repaired in a manner that prevents mine gas explosions.”
The changes to DMR activity will be at a more strategic level with more input in certification schemes, locally and internationally, on the agenda.
DMR safety officers will join the national certification management committee, which will be working towards the goal of a high-integrity certification process.