Staying ahead of the regulations

14 February 2017

All new motors placed on the market – between 0.75 kW to 375 kW – are now required to meet the IE3 efficiency level. Control Engineering Europe finds out what needs to be done to stay ahead of the regulations.

January 2017 marked a milestone year for electric motors, with all motors rated from 0.75 kW to 375 kW now needing to meet either the IE3 efficiency level (driven direct online) or the IE2 level if fitted with a variable-speed drive (VSD). 

The energy costs of a 110 kW motor represent up to 99% of the overall lifecycle costs. By increasing the efficiency of a motor, the energy consumption can be significantly reduced – and along with it, the associated costs. 

The European Commission (EC) is proposing to further extend these changes to include low- and medium voltage motors, VSDs and those products currently excluded from the regulations such as explosion-proof and brake motors. “With the regulations potentially extending to low- and medium-voltage motors and variable-speed drives, there is a lot to consider for users of motor-driven applications,” said Marco Veeckman, sales and marketing manager of ABB’s motors and generators business. “It can be a confusing landscape with the regulations meaning different things to OEMs, machine builders, system integrators or end-users. It’s more important than ever, therefore, to seek the right advice: Which motor is most suitable for your application? When do you need a VSD? Is your application dimensioned correctly and what is the optimum solution for your process or machine?”

It should never be taken for granted that all IE3 motors are manufactured with the highest quality materials. Just because a motor has an IE3 stamp does not mean it is reliable. Testing of drives and motors in combination is a good measure of a drive system’s reliability. 

ABB has facilities to allow for the testing of motors and drives using the loading conditions that simulate the actual application. It precisely measures motor/drive dynamic performance, loadability and efficiency – parameters that are needed to find the optimal drive system for the application. Optimising the drive system in this way means lower costs, reduced space requirements and energy savings.

Using the test results to optimise the motor/drive combination also prevents over-dimensioning which would make the initial cost of the drive system much higher than it should be, which means the payback time for the investment is longer. 

Manufacturers must mark rating plates with the nominal efficiency at 100%, 75% and 50% of the rated load, except for small motors, which, due to the limited size of the rating plate, only need to show nominal efficiency at only 100% rated load.

Additionally, all motors must show their IE class (IE2, IE3 or IE4) and year of manufacture on the rating plate. Manufacturers are also required to provide certain other technical documentation on their free-access websites. 

All IE2 motors placed into the market since January 2015 must be used with a VSD. As such, these IE2 motors need to display notification of the VSD use on the rating plate or on an additional sticker/plate. The notification must also feature in the motor’s technical documentation. 

It is important to keep up with the latest VSDs and electric motor technologies. For example, if an application can be run by a variable speed drive, then a synchronous reluctance motor, or SynRM, is suitable.

A SynRM has no rotor windings in the traditional sense. This means that the rotor suffers virtually no power losses, keeping its temperature much lower than in conventional rotors. Losses are typically 40% lower than in an equivalent induction motor, making it more efficient. 

With less heat produced, the bearings also run much cooler than with other motor designs, reducing bearing failures, which are the biggest source of motor stoppages. Compared to permanent magnet motors, SynRM is lighter, less expensive and easier to repair yet gives the same performance levels.

There is a common misconception is that SynRMs cannot handle high torque applications. Yet, used with variable speed drives, they are more than capable of handling the type of high torque applications found in industries such as food and beverage, cement and mining.

The motor is available in two distinct packages. The first is a motor which is the same physical size as a standard induction motor but operates at IE4 efficiency levels. The second variant is called “High Output” (HO), which is typically two frame sizes smaller for the same equivalent power compared to induction motors and still maintains IE3 energy efficiency levels.

OEMs and machine builders  
Original equipment manufacturers (OEMs) and machine builders need to choose their motor supplier carefully. Not only is the availability of a full range of IE3 motors from a single vendor important, some OEM products will need to consider the use of VSDs. Finding a supplier conversant in matching both drives and motors will save considerable time and costs.

OEMs should be gearing up to use IE3 motors in their machines or applications and should be specific with their suppliers about what they want and what they do not want. For instance, with constant torque applications, where there may be no need to turn down the speed, fitting an IE2 motor and a VSD may not be cost-effective.

OEMs should also look at how the change will affect their logistics and supply chain. For example, IE3 motors may be larger than equivalent IE2 motors. Some redesign of product ranges may be necessary to take account of new motor frame sizes, motor cable length and fixings. 

However, some manufacturers, like ABB, have designs whereby the shaft height of a standard IE3 motor aligns with that of the IE2 standard motor, making a like-for-like replacement easier. Furthermore, as the higher efficiency is often achieved using the same housing, while the motor may be heavier, the need to change the machine’s mechanical structure is avoided in many cases.

System integrators  
System integrators should by now have established a preference for IE3 motors for high duty applications. In this way, system integrators can help ensure the future compliance of their design. It is useful to put a greater focus on energy consumption - use motor starters where they offer the most efficient solution, for example, in fixed speed, constant load or low duty applications. 

The Regulation states that motors rated for continuous duty are covered. This means motors that are capable of continuous operation at their rated power with a temperature rise within the specified insulation temperature. Apart from motors rated for continuous operation (S1), other duty cycles to be considered as continuous duty are: S6, continuous duty with intermittent loads and S3, intermittent duty with a continuous duty factor of 80 percent or more. 

Duty types are defined in IEC/EN 60034-1 Rotating electrical machines – Part 1: Rating and performance.

VSDs should be used when there is a need to regulate the speed and in applications where they bring added value, such as improvements to the operation or maintenance costs of a process or a significant energy saving.

IE3 motors, typically, carry a 10 to 20% premium above the purchase cost of IE2 motors, but offer payback of this extra cost in a little less than two years. 

Take for example, a typical 200 kW 4-pole motor, running at 8,000 hours a year with an electricity cost of 0.1 euro/ kWhr. An IE2 motor would cost 169,521 euros in annual running costs, while the IE3 would cost 167,945 euros, providing a saving of 1,576 euros a year or 131 euros a month. The payback for this premium would be well below two years.

It is also worth considering the classes of motor that the regulations do not cover. These include motors rated at over 1000 V, motors intended for explosive atmospheres and brake motors.

The regulations are a little more complicated for dual-purpose smoke extraction motors. These are covered by the regulations if the motor can be tested by the motor manufacturer at rated power and normal ambient with its own fan. This type of motor is covered by EU MEPS and must have the correct IE markings.

The motor does not fall under the regulations if it cannot be tested independently at rated power, that is, it requires a fan supplied by an outside manufacturer). These products – known as TEAO or Totally Enclosed, Air Over motors – are not covered by EU MEPS.

Another important aspect for end-users is the management of their motors and the policies that govern this. Now is an ideal time to review your motor management policy and it certainly should be reviewed if it hasn’t been in the last three years.

One of the major changes should be to your procurement policy, to ensure that all motors meet the legal minimum requirement of IE3. When looking at the motors currently installed, those working for 7,000 to 8,000 hours a year should receive particular attention. These are costing the most and may be due for replacement, so they are ideal candidates for replacing with IE3 standard motors.

Check rating plate
Check the motor rating plate and read the Declaration of Conformity, which should show compliance with the Ecodesign Directive 2009/125/EC and Regulation 640/2009. The rating plate should be stamped with the efficiency class – IE2 as a minimum if the motor is to be used with a VSD and IE3 if the motor is to be direct-on-line (DOL) fed – and efficiency values. The IE class stamped on the plate must be based on the lowest efficiency value at the rated voltage/frequency/output combination shown on the rating plate.

IE2 motors must also have a marking to indicate that they can be used only with a VSD. Also check your existing spares, as it would not be beneficial to replace a failed motor with an inefficient motor. 

Manufacturers and repair shops may repair or rewind motors and return them to the customer after the requirements come into force. Repairing and returning to use is not considered to be ’placing on the market’ and hence the requirements do not apply.

However, end-users do need to carefully consider the advantages of replacing the motor rather than having it rewound. Each rewind normally will reduce a motor’s efficiency. If not properly carried out the reduction can be as much as 3% or more, and in the worst case the motor may not be used at its rated power.

When total life cycle costs are taken into account, a new high efficiency motor is generally a better alternative than rewinding. The initial purchase cost of a motor is typically 1 to 2% of the total cost of ownership, and is much lower than the motor’s lifetime operating expenses. In many cases the payback period for a new motor is less than two years.

It is important for all parties to meet with their suppliers and decide how the regulations will affect them and what purchasing strategy will be best for their organisation. The regulations are here and putting off these crucial decisions is not an option.

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