One spark might be enough

The standards that apply to electrical production equipment used in hazardous dust areas are changing rapidly. For those equipment owners and manufacturers that do not keep abreast of these changes, there can be serious consequences, warns Gordon Low of Cooper Crouse-Hinds (UK) Ltd.

"The standards governing electrical equipment for use in hazardous dust areas are changing so rapidly that buyers and users of electrical production equipment are finding it difficult to keep up," says Gordon Low, OEM sales engineer at Cooper Crouse-Hinds (UK) Ltd. "However, if they do not keep abreast of the changes, they run the risk of a dust explosion occurring in their plant due to inadequately protected equipment. The risk of non-compliance or negligence is simply too high."

The risk of a dust or powder explosion occurring in a manufacturing plant should not be underestimated. Around 2,000 dust explosions occur in Europe every year, affecting all types of companies, including manufacturers of sugar, coal, cocoa, flour-based goods, milk powder, tea, grain, fodder and tobacco, as well as wood and metal processing companies. Any environment in which dust or powder is allowed to gather on hot surfaces or that could be ignited by a spark from electrical equipment is a potential risk.

The cost, in terms of lives lost and damage to plant, as a result of a dust explosion can be enormous. In February 2008, a catastrophic dust explosion occurred at the Imperial Sugar Refinery in Port Wentworth, USA. The dust explosion killed 13 people and injured many more.

Refer to picture above: The standards that apply to electrical production equipment used in hazardous dust areas are changing rapidly, warns Gordon Law.

Owners of new electrical equipment are governed by the compulsory European directive 1999/92/EC, implemented in the UK as the 'Dangerous Substances and Explosive Atmospheres Regulations 2002' (DSEAR). From 2006, this directive also includes 'old' as well as 'new' equipment. Owners of electrical equipment are required to identify the risks of explosion; implement explosion protection measures such as avoiding sources of ignition (secondary explosion protection); define zones in areas at risk from dust explosions; create an explosion protection document; use suitable production equipment; and to create a test plan.

For electrical equipment in areas at risk from dust explosions, a new series of stricter standards, EN61241, have been introduced, which came into effect from the 1^st October 2008. The standards supercede the existing standard EN 50 281. Within EN61241, one of the main protection types for electrical equipment at risk from dust explosions in accordance with ATEX Directive 94/9/EC, is the protection by enclosures type "tD".

This protection type is where the electrical equipment is protected by an enclosure to prevent dust penetration and where measures have been taken to limit the surface temperature
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The main changes to this standard are concerned with impact energy - high demand on impact energy as in Zone 1; electrostatics - electrostatic conductance of the enclosure; and ageing resistance - high demand on the ageing resistance of the plastic enclosure. "It is imperative that production equipment owners are aware of these changes in standards when sourcing or upgrading electrical production equipment for hazardous dust areas," says Low.

The goal of the current European Directives is to protect manufacturing plants from dust explosions and to prevent damage or personal injury. As Low points out: "A recent report from the HSE [Health & Safety Executive] stated that on average there are 70 to 100 incidents each year in the UK that involve explosive atmospheres. In one particular year, the HSE investigated five fatal accidents involving explosive atmospheres and 16 major accidents. It's not something companies can afford to ignore."

In addition, there are further pressures to comply, as Low warns: "On the 6th April 2008, the Corporate Manslaughter and Corporate Homicide Act was introduced in the UK. This means that companies found guilty of negligence or non-compliance could face severe fines and/or imprisonment. This means that companies' internal control of health and safety is a business risk that senior managers can no longer regard as a minor matter. Directors must act immediately in order to raise the status of health and safety so that it assumes the same level of boardroom importance as other business risks," advises Low.

Companies looking to reduce costs at the expense of health and safety should think again, says Low. According to the HSE, total compliance costs to UK industry are estimated at £350 million over the ten years from 2002-03, almost all of which is attributable to action that should be taken in any case under existing regulation. Against this cost, the total losses associated with incidents involving dangerous substances are valued at just over £800 million over ten years.

For owner operators that need technical advice and guidance on explosion-protected electrical installations and the relevant EU Directives and standards, Cooper Crouse-Hinds provides a comprehensive range of explosion-protected electrical equipment, including fluorescent light fittings, emergency lighting, switches, terminal boxes, control stations, portable lamps, connectors and plugs.

For more information or for your free copy of the company's full range dust catalogue entitled "Catalogue Dust-Ex 712: dust explosion-protected luminaries and apparatus", contact Cooper Crouse-Hinds' UK sales office, Tel: 02476 308930 or email: sales@ceag-crouse-hinds.co.uk

Cooper Crouse-Hinds (UK) Ltd in profile
As part of the Cooper Industries Group, Cooper Crouse-Hinds (UK) Ltd is the number one company in the field of explosion protection. Committed to technological progress, the company develops and manufactures a range of products that cover all the requirements currently placed on modern, explosion-protected, electrical installation technology, including illumination, safeguarding, signaling, controlling, instrumentation and distribution of electrical energy in potentially explosive atmospheres. In the company's production plants in Germany, England and Spain, the company manufactures a wide range of products for explosion protection.

Cooper Crouse-Hinds supplies products that comply with all the latest directives and standards - worldwide. In addition to systems and components built to ATEX Directives and European Standards, the company also provides solutions that have been certified to both IEC and NEC standards. Moreover, the company also has a large number of other national approvals, e.g. for Eastern European countries, China and North America. With Cooper Crouse-Hinds you can get all you need from one source.

For further information, e-mail: info@ceag-crouse-hinds.co.uk or view website: www.cooperindustries.com   Refer to page 111

Outram power-quality analyser revolutionises on-site
detection of power-losses and disturbances for PQE Ltd

Outram Research Ltd - a specialist manufacturer of leading-edge data-loggers - has revolutionised the way in which global power-loss trouble-shooter, PQE Ltd, takes on-site measurements which enable commercial and industrial customers to reduce energy costs by identifying power losses in their electricity supply.

PQE Ltd provides customers world-wide with a power correction service which requires them to locate and identify power losses and disturbances which increase energy usage and costs. The recent introduction of Outram Research's latest power-quality analyser has enhanced and simplified the way in which PQE Ltd carries out on-site measurements of harmonic distortion, supply interruptions and load-profiles.

Harold Birtwistle, Managing Director, PQE Ltd, commented: "Outram's Ranger PM7000 out-performs all of our previous recording equipment. It enables us to measure harmonic distortion in its totality as well as individual harmonic currents and voltages in KWs, KVAr and KVA, and also power factor, voltage dips, sags, spikes and flicker. The great beauty is that it measures these parameters simultaneously and it has a prodigious memory. This means that it doesn't have to be downloaded before it is used again and saves all the trouble of taking a laptop to site to prevent new recordings overwriting old data."

"Most recorders will catch spikes when they create over-voltages, but catching these is dependent on when they hit the sine wave and whether their polarity is the same as that of the waveform. If a spike's polarity is opposite to that of the sine wave, the resulting voltage is the difference between the two, so there is no overvoltage and the events will not be detected by a run of the mill recorder," explained Harold, "However, the Ranger's high-speed recording process looks for and captures distortion over all of the waveform and it has revolutionised the results we get. Recordings can be used to confirm a site's compliance (or otherwise) with the harmonic distortion limits stipulated in engineering recommendation G5/4."

John Outram, Managing Director of Outram Research, explained further: "Our units offer three sampling speeds from 19.2 k to 153.6 k to 1.23 M Samples per Second. We have designed the PM7000 to make data management and analysis easier. Not only do we capture the distortions at any part of the cycle but we identify and then rank them in order of severity, discarding the least interesting as more are captured. This eliminates the laborious and reiterative process of manually setting thresholds and during analysis users can go straight from one disturbance to the next."

The market-leading Ranger PM7000 power-quality analyser is the industry's only Cat IV 600V Phase A-powered analyser and offers the most comprehensive range of power quality measurements of any instrument in its class. "The recent addition of USB compatibility allows data to be downloaded automatically onto a USB memory-stick for offline analysis, in practice giving the user the benefit of virtually unlimited memory combined with fast, convenient data retrieval which requires no skill or special training," explained John Outram.

Released in January 2009, the latest version, of the Ranger PM7000 captures data to IEEE 1459 and IEEE 100 parameters which will provide PQE with an improved measurement tool to correctly size power factor correction capacitors. The Ranger PM7000 also measures parameters to the IEC61000-4-30 standard, including harmonics and interharmonics to IEC61000-4-7, and flicker to IEC61000-4-15. The IEEE standard 1459 is an emerging standard that defines more effective ways of measuring the parameters which provide detailed information on power consumed due to losses caused by imperfections in the sinusoidal waveforms of the current and voltage.

Harold concluded: "We are so impressed with the product, and with the back-up we received from Outram Research, that we have already purchased a second Ranger PM7000."

Key Facts of the Ranger PM7000
1) Enhances field measurements of power quality and on-site detection of power losses for trouble-shooting specialist, PQE Ltd. 2) Automatic download to USB memory-stick provides unlimited memory capacity and eliminates the need to take a laptop on-site. 3) Industry-leading power-quality analyser captures IEEE 1459 and IEEE 100 parameters to support customer energy-reduction initiatives.

PQE Ltd in profile
PQE Ltd is a private limited company which designs, manufactures and installs power factor correction equipment and harmonic filters. The company has operated since 1998, but senior employees have more than 40 years experience in the products mentioned above. We supply countries worldwide including Europe, Middle East, Asia and Africa. In addition, PQE Ltd provides site measurements of harmonic distortion, supply interruptions, load profiling and electrical problem troubleshooting at customer premises.

For information, e-mail: valerieoutram@outramresearch.co.uk or sales@outramresearch.co.uk or view website: www.outramresearch.co.uk