Costing the earth

Although most engineering managers are getting the message that high-efficiency electric motors and variable speed drives (VSDs) – together, but also separately – pay for themselves very quickly in most applications, there could be a problem looming. There seems to be a lack of awareness that phase two of the Eco Design Directive 2009/125/EC (amending 2005/32/EC and formerly the Energy Using Products Directive) hits in just 18 months, imposing new mandatory minimum standards on virtually all three-phase induction motors with rated outputs from 7.5-375kW. So says Ian Allan, ABB's general manager for motors and generators, who worries that industry is sleepwalking towards the 1 January 2015 deadline. From that date, the minimum efficiency class for motors being put into service, in the above range, will move up from IE2 (high efficiency, comparable to the old Eff1 under the European voluntary CEMEP arrangement) to premium efficiency IE3. IE2 will only be accepted if motors are equipped with VSDs – which reduce energy consumption by far more than any motor efficiency improvement, certainly on centrifugal loads, such as pumps and fans that can tolerate speed control. "The industry seems to think that the directive's job was done back in 2011, when it first led to IE2 motors being made a legal requirement," comments Allan. "But that's not the case. And, while there is no onus upon anyone to do anything yet, they should at least be aware and considering auditing their motor assets." Allan and others believe that the separate Energy Related Products (ERP) directive (2009/125/EC) – which introduces mandatory efficiency levels on driven equipment, such as pumps and fans – may also be playing some part in distracting attention from motors. Fan systems will be first to come under that directive's jurisdiction, later this year, but others will follow – to the tune of more than 30 plant equipment combinations. "So, OEMs have been striving to get their own houses in order," asserts Allan, indicating that, for them, electric motor requirements must surely have slipped to the back burner. "However, it is important that the changes to the minimum efficiency standards for motors in Europe are not overlooked." He's right – but why the urgency? Well, let's look at the facts. In brief, a 30kW four-pole IE1 motor would have been running at around 91% efficiency. Move that up to IE2 and that same motor has to deliver 92.3%. IE3 takes that up a further notch to 93.6% efficiency. That's a substantial difference. So, on the one hand, a motor estate review might help manufacturers, in terms of considering their spares inventory and avoiding obsolescence. But on the other, it would also reveal those most likely to benefit from the operational energy, and therefore cost, savings that an early upgrade to IE3 would bring. And with payback on upfront costs of premium efficiency motors generally accepted as sub-two years for those running continuously for 8,000 hours per year, and five years for 2,000 hours, that's most of them. Bear in mind two further points. First, IE3 motors are not as expensive as they used to be, because engineering know-how, manufacturing techniques, standardisation and volumes have all improved. Allan suggests that a realistic premium for IE3 motors today is 15% over IE2, compared with around 30% just a couple of years ago. And he states that they're much more readily available from stock, as opposed to order-only items. But second, if you don't adopt some kind of motor purchasing policy soon, you'll be at the mercy of the fan, pump, or compressor manufacturers, who may not feel under any pressure to supply more than the current IE2 minimum. And that means you could be missing out. "Remember, OEMs are mostly not interested in helping you to reduce energy costs for their kit. They're interested in getting your business," states Allan. And while that may not be the case – some will see an opportunity to differentiate themselves by incorporating IE3 motors and/or VSDs early and marketing the benefit of lower running costs – it's as well to be on the case. Incidentally, much the same reasoning applies to installing VSDs. As Allan puts it: "As with most electronic systems, the competitiveness of VSDs has increased significantly. Also, in terms of the technology, engineers can do a lot more with them than they could, say, a decade ago." And awareness of that fact has increased massively. "We reckon that about 30% [of the market] is now using VSDs or looking to buy them, which is just about the clearest indicator that there's a worthwhile benefit there and it's tangible – if the upfront cash is available." Hence the growing number of VSD suppliers and the improvements not only in terms of industry-centric functionality, but also ease of implementation and operation. Look, for example, at Eaton Corporation's recently launched PowerXL range of VSDs, which cover ratings from 0.37 to 250kW in two ranges. Pluggable modules enable these units to be incorporated quickly and simply into Eaton's SmartWire-DT connection and communication technology, which eliminates conventional wiring. Eaton describes the development as "expanding our lean strategy in the machine building and panel building sectors". And with PLC and PID (closed-loop, continuous) control functionality making them suitable for driving devices such as pumps, fans, conveyor belts, cranes, winding machines, compressors and lifts, etc, it's hard to argue the point. As for why 'lean', the firm says it makes the claim not only on account of the reduced wiring effort, but also due to the reduced planning and engineering required – a reduction, it says, of up to 70%. It also cites "noticeable improvements with regard to system availability and safety", and the potential for extended drive condition monitoring and remote maintenance. By the way, Eaton and others also now offer ROI (return on investment) calculator and system selector software tools to make the whole project process way easier than it used to be. But the last word goes to Steve Brambley, deputy director of GAMBICA, the trade association for the UK's instrumentation, control, automation and laboratory technology industry. "It is worth remembering that 90% of the lifetime cost of an electric motor comes from its energy consumption. So, the old [inefficient] asset you think you are sweating may well be sweating you." And he adds: "If just half of Britain's electric motors were reduced in speed by 10% that would mitigate the carbon emissions of 9.8 million executive saloon cars every year... The energy cost of a system should be the first thing a buying team looks for in a quote, as it may well be the single item that most affects the bottom line over time."