Ensuring Electrical Motor ErP Directive Compliance

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Across industry, electrical drives account for the lion’s share of electrical energy consumption and from 1st January 2017, all electrical motors will be subject to minimum levels of efficiency. This requirement is the next step towards energy efficiency under the ErP Directive and affects a huge 70% of the commercial market. Here, Mark McCall, Marketing Manager at Newey & Eyre, looks at the options available to ensure compliance.

By Mark McCall, Marketing Manager - Newey & Eyre — By Mark McCall, Marketing Manager – Newey & Eyre

In the UK, in 2014, chemicals were the largest industrial energy consumer, responsible for 14% of total consumption, followed by food, drink and tobacco at 12%¹. These, among other industries, are already challenged to curb their energy consumption under Climate Change Agreement (CCA) schemes; voluntary agreements which enable businesses to receive discounts on the Climate Change Levy.

A number of process industries have umbrella CCA sector commitments which set out energy efficiency targets, giving them a target saving to be achieved by 2020 from the base year 2013.

For the food and drink sector, the target is an 18% reduction with 17% for plastics, 13.6% for brewing, 7% for bakers and paper manufacturers and 6.1% for ceramics.

Huge steps have been made in CO² emission reduction in the UK, but our industrial sector still ranks in the top three offenders for carbon emissions in Europe, alongside Germany and Italy.² Designed to help tackle this, the ErP – Energy-related Products – Directive applies across products that use energy or have an indirect impact on energy consumption sold in the European Economic Area and the next wave of its requirements targets electric motors in the industrial setting.

Electrical motors are widely identified as one of the largest consumers of energy worldwide.

According to the Sustainable Energy for All (se4all) initiative, there are six product areas that will collectively account for around 55% of global electrical consumption by 2030 and one of those is motors. Use varies by sector but the impact of electrical motor usage can be significant – in plastics processing, for example, approximately two thirds of energy costs are a result of electric motor usage.

Reducing this usage has the potential to be beneficial not only in broad climate change terms but also for the bottom line of individual businesses so the attention focused on drives by ErP could be seen as a wake-up call to significant energy cost savings.

Consider the directive changes…

The requirements of the directive are that, from 1st January 2017, all squirrel cage motors with a rated output of 0.75 to 375kW must either be supplied as an IE3 motor or as an IE2 motor with avariable speed drive (VSD). Choice of drive engineering is dependent on the application.

Where fixed speeds or lower switching frequencies are involved, traditional motor starters offer the more energy efficient solution, whereas VSDs are more appropriate for applications with variable speeds or frequently alternating loads.

IE3 premium efficiency fixed-speed motors will deliver the energy savings that tick the regulator box. They are, however, characterised by a number of properties, including higher starting currents which means that it is particularly important to use high-quality switchgear and protection components with the correct trip pattern and with a switching duty specifically designed for the IE3 motor being used.

IE3 motors achieve the required energy savings, but can be more expensive to purchase leading to a longer payback time. Fixed speed motors operate most efficiently when their load equals, or is slightly greater than, the rated capacity.

If motors are larger than needed for their applications, they will not reach the design load so will not run at optimum efficiency. Accurate motor sizing is therefore essential in order to achieve true energy efficiency.

Fixed speed control is appropriate in applications where load demands maximum motor speed or mechanical constraints do not permit speed variation. Low voltage switchgear in a well-designed system can achieve significant energy savings, but these relate directly to the amount of time the motor is switched off.

This can either involve the simple expedient of switching systems off when they are not needed, or designing an intelligent system incorporating techniques for determining precisely when the motor needs to be operational.

Another choice..

Alternatively, significant savings can be achieved by using an IE2 motor with a VSD, which as well as delivering energy savings can offer shorter payback times. In many applications, particularly centrifugal fans and pumps, compressors and material handling, the energy savings alone provide a conclusive argument for the incorporation of a motor with a VSD.

For example, in many fan and pump applications, efficiency gains of between 20% and 70% can be achieved. Other benefits also include increased motor longevity, reduced maintenance and a reduced risk of motor and machinery damage during start up, running and shutdown.

Traditionally, VSDs have generally been specified when part of a larger or more complex control system, chiefly due to a gap in the market for an enclosed direct online (DOL) product that incorporates the simplicity of a DOL installation and the benefits of a VSD.

For example, we have developed the Newlec EcoStart which is an energy-efficient enclosed motor starter that offers all of the benefits of a VSD which combined with an IE2 motor can be ErP compliant.

In many instances, motors are over-rated for their application and the speed can be reduced overall to delivery energy savings. As an out-of- the-box solution, EcoStart is supplied to run at85% motor speed which immediately provides up to 40 per cent electrical energy savings.

Additionally, it can be set to operate precisely to the requirements of the individual application. As an example of the potential savings, with a 4kW motor with an EcoStart motor starter, set to run at85%, in a system that is operational for 12 hours a day, 250 days a year, with an electricity cost of12 pence per kW/h, the user could expect to save £836 per annum on energy bills with a payback period of 1.5 years.

The specific application will determine the choice of motor, with the higher costs of higher efficiency motors being offset by the ongoing savings that can be made in energy costs with the correct choice. ErP compliance gives engineers the baseline in terms of the minimum permitted efficiency and creates the opportunity to deliver solutions that can lead to lower running and energy costs, reduced maintenance and overall system downtime.