Hazardous area motors offer high energy efficiency

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Oil, gas, petrochemical and other similar industries can now enjoy the same energy-saving benefits as general industry with the launch by WEG of Premium Efficiency (EFF1) EEx d/EEx de, and both Premium Efficiency and Top Premium Efficiency (EFF1+) EEx nA hazardous area motors. The new motors offer 'industry-leading' efficiencies up to 96.8 per cent and are available in a wide range of sizes up to 315kW.

The WEG premium efficiency EE x d and EEx de motors meet all the requirements of applicable IEC and CENELEC Standards, as well as the ATEX Directive 94/9/EC (Category Ex II 2 G EEx d or EEx de II T4 (Zone 1). They are designed to operate safely in category 2, Zone 1 (Groups IIA and IIB) environments where flammable gases, or vapours gather in sufficient volumes to generate explosions. In these environments the EEx d and EEx de motors provide the high levels of efficiency necessary to achieve substantial energy savings on equipment such as fans, pumps, powerpacks, blowers, crushers, conveyor systems, mills, cranes, and other plant located in hazardous areas.

Combustible gases and dusts

Offering the same energy-saving benefits in category 3 hazardous environments, WEG's Premium Efficiency (EFF1) and Top Premium Efficiency (EFF1+) dual labelled EEx nA / DIP motors are classified as Zone 2, Groups IIA, IIB and IIC, and Zone 22, DIP. This dual classification provides a major benefit for users in that one motor will suffice in atmospheres containing both combustible gas and non-conductive combustible dust. In addition, the EFF1+ motor variants offer 'market-leading' efficiencies of up to 96.8 per cent.

Importantly, in terms of reliability, these hazardous area offerings employ the same well-proven design as WEG's W21 line of high-efficiency motors. With many types of high-efficiency motors, the quality of insulation, heat dissipation and mechanical protection may be no different to a standard motor. WEG, however, has taken a different approach; the company's W21 design offers reliability-enhancing improvements such as Class F, (Class H optional) insulation, reduced temperature rise, improved heat dissipation, lower bearing temperatures, low-noise operation, and high levels of ingress protection (IP55 standard, with IP66 optional).

In common with WEG's newly-introduced range of dust ignition-proof motors, the EEx d/de and EEx nA hazardous area motors are inverter-rated to enable maximum energy savings from matched motor/drive combinations. This means that they are highly efficient in dealing with the higher peak voltages and faster voltage rise times generated by the IGBTs (high dV/dt) used in the latest generation of VSDs. Moreover, when supplied as a package with a variable speed drive from WEG's CFW ranges, they are backed-up by a three-year warranty.

In terms of energy efficiency ratings, the EEx d/de and EEx nA motors either meet or exceed CEMEP[1] or WIMES[2] requirements. Premium Efficiency types meet the requirements of CEMEP's and WIMES' EFF1 level, while the Top Premium Efficiency EFF1+ units comfortably exceed these requirements. All of these motor types are registered with the DEFRA[3] to enable users to claim enhanced capital allowances (ECA) on the motor purchase – which can make a substantial contribution to reducing the payback time.


[1] CEMEP is the European Committee of Manufacturers of Electrical Machines and Power Electronics.

[2] WIMES is the Water Industry Mechanical and Electrical Specification.

[3] DEFRA is the UK Department of Environment, Food and Rural Affairs.

27 March 2007

WEG Electric Motors (UK) Ltdvisit website
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