Custom service and maintenance equipment for hazardous areas im-proves efficiency and safety of process plants
Thursday, June 3rd, 2010
The servicing and maintenance of electrical equipment in hazardous areas can be time-consuming and costly, particularly if engineers are not provided with the right tools to carry out the job quickly and safely. Custom designed equipment is now available to assist, says Gordon Low of Cooper Crouse-Hinds.
As industrial processing plants become more complex and safety requirements more strin-gent, these plants have to become more efficient in terms of their maintenance and servic-ing activities. The objective is to minimise costly production downtime and to guarantee the safe operation of plant, machinery and other electrical equipment at all times.
However, when it comes to the repair, replacement, servicing and maintenance of electri-cal equipment in hazardous areas, the challenges facing servicing and maintenance personnel can be daunting, time-consuming and costly, particularly if the engineer is not provided with the appropriate tools.
Furthermore, in hazardous gas or dust areas, before any electrical apparatus – such as electric motors, variable speed drives, valves, actuators and sensors – can be installed, repaired or maintained, the technician needs to ensure that the electrical connection or disconnection procedure is carried out safely, with all electrical apparatus isolated from the power supply. These measures are necessary because the explosion-protection of the apparatus becomes ineffective once the enclosure is opened. Ensuring that all appropriate fire protection and safety fencing procedures are carried out is also important here. This type of preparation requires a Hot Work Permit, which can take 24 hours to be issued. Even if the permit arrives in a couple of hours, costly production downtime may already have been incurred.
Therefore, when engineers look at selecting the most appropriate electrical equipment for their plant, the most important factors to consider are the life of the equipment, the likely maintenance effort required, how easy the equipment will be to use, and whether the equipment has any smart maintenance features and support options.
Selecting electrical equipment on the basis of price alone can have far more damaging effects on the business in the medium to long term. A higher frequency of product failures and breakdowns may occur after installation due to inferior quality design and manufac-tured components. Companies should therefore consider the complete product lifecycle cost of the electrical equipment – including purchase price, initial installation costs, maintenance life costs, scrap costs (due to failure of pumps, valves and instrumentation) and the cost of any unforeseen production downtime – before making any purchasing decisions. Often, this is referred to as the Total Cost of Ownership of a product.
In a typical hazardous area plant such as an offshore oil platform or onshore petro-chemical plant, selecting the right portable lamp, cord reel, plug distributor or repair socket to work with, will have a significant positive impact on the efficiency of the maintenance and servicing activities – and therefore on how productive the business is.
Engineers should therefore start by ensuring that all their existing electrical equipment and new purchased products comply with the relevant European safety regulations and quality standards. Companies also need to conduct proper risk assessments on equipment located in hazardous gas or dust areas. This must comply with the latest Health and Safety and European ATEX Directives (ATEX 137 or ATEX 118a, 1999/92/EC).
The minimum requirements stipulated in Directive 1999/92/EC (ATEX 137) are that “all necessary measures shall be taken to ensure that the workplace, the work equipment and the associated connection devices…are maintained and operated in such a way as to minimise the risks of an explosion…”
While a wide range of standard, off-the-shelf explosion-protected electrical equipment is now available to help engineers minimise service and maintenance costs, some of this equipment can now be customised to suit the individual requirements of a plant or off-shore oil platform.
On the lighting side for example, portable Ex-lamps and torches, including LED versions, can be activated using one hand. Spotlights can be provided with displays showing the user how much operational time is remaining. Single and double-lamp machine lights can be provided with rugged pipe made from polycarbonate and protected to IP68.
For high power lighting in Zone O hazardous areas, Ex tank inspection lights can be pro-vided to check oil or gas storage tanks, quickly and safely. These lights can also be inte-grated with a custom designed transport trolley if required. Other lighting products for haz-ardous areas include emergency lights, pendant light fittings, floodlights, and lamps for outbuildings and mast bases.
Another important consideration for service and maintenance staff is the availability and flexibility of power supply. Technicians require cord reels and socket distributors that comply with the European ATEX Directives, enabling repairs and servicing to be carried out in hazardous zones. For example, portable Ex socket distributors and cable drums are available for providing a flexible power supply to portable electrical equipment located in zones 1, 2, 21 and 22. The objective is to minimise the time and effort required by the engineer, whilst guaranteeing the safety of personnel at all times.
One area in which Cooper Crouse-Hinds has seen continued growth in recent years is in mobile power distributors. Often custom engineered for specific projects, these typically comprise a trolley, Ex plugs and eXLink plug connectors.
The ergonomically designed trolley is used to safely transport distribution boxes and other explosion-proof electrical equipment around a plant. The Ex plugs have a flexible mount-ing plate with wired Ex plugs for providing electrical power to various types of equipment.
Cooper Crouse-Hinds’ own eXLink plug connections can then be used to enable electrical equipment – including actuators, motors, submerged pumps, liquid level sensors, floating switches – to be connected and disconnected quickly and safely, without compromising the safety or integrity of the installation.
Enabling users to maintain apparatus on a proactive or predictive basis, the eXLink range of Ex-approved plug-and-socket connectors from Cooper Crouse-Hinds UK Ltd, enables the connection and disconnection of electrical apparatus in potentially explosive environments, without the use of tools and without the engineer having to isolate the apparatus from the mains or disconnect the terminals.
The eXLink range, which includes connectors, plugs, receptacles, inlets and elbows, can be used for any instrumentation device or electrical apparatus.