ABB - Technical Guide Book (todos em um), Notas de estudo de Tecnologia Industrial

Baixe ABB - Technical Guide Book (todos em um) e outras Notas de estudo em PDF para Tecnologia Industrial, somente na Docsity! Q õ E S [a [7 q 2 ABB drives I Technical guide book Technical guide book I ABB drives 5 1. Direct torque control explains what DTC is; why and how it has evolved; the basic theory behind its success; and the features and benefits of this new technology. 2. EU Council Directives and adjustable speed electrical power drive systems is to give a straightforward explanation of how the various EU Council Directives relate to power drive systems. 3. EMC compliant installation and configuration for a power drive system assists design and installation personnel when trying to ensure compliance with the requirements of the EMC Directive in the user’s systems and installations when using AC drives. 4. Guide to variable speed drives describes basics of different variable speed drives (VSD) and how they are used in industrial processes. 5. Bearing currents in modern AC drive systems explains how to avoid damages. 6. Guide to harmonics with AC drives describes harmonic distortion, its sources and effect, and also distortion calculation and evaluation with special attention to the methods for reducing harmonics with AC drives. 7. Dimensioning of a drive system. Making dimensioning correctly is the fastest way of saving money. Biggest savings can be achieved by avoiding very basic mistakes. These dimension- ing basics and beyond can be found in this guide. 8. Electrical braking describes the practical solutions available in reducing stored energy and transferring stored energy back into electrical energy. 9. Guide to motion control drives gives an overview of high performance drives and motion control. 10. Functional safety guide introduces the Machinery Directive and the standards that must be taken into account when design- ing a machine, in order to ensure operational safely. Contents 10 9 8 7 6 5 4 3 2 1 Technical guide No. 1 Direct torque control - the world’s most advanced AC drive technology ABB drives 4 Direct torque control | Technical guide No. 1 Technical guide No. 1 | Direct torque control 5 1 Contents Chapter 1 - Introduction ............................................................................7 General ..............................................................................................7 This manual’s purpose ........................................................................7 Using this guide .................................................................................7 What is a variable speed drive? ...........................................................8 Summary ...........................................................................................8 Chapter 2 - Evolution of direct torque control ...........................................8 DC motor drives .................................................................................9 Features ........................................................................................9 Advantages ...................................................................................9 Drawbacks ..................................................................................10 AC drives - Introduction ....................................................................10 AC drives - Frequency control using PWM .........................................11 Features ......................................................................................11 Advantages .................................................................................12 Drawbacks ..................................................................................12 AC drives - Flux vector control using PWM ........................................12 Features ......................................................................................12 Advantages .................................................................................13 Drawbacks ..................................................................................13 AC drives - Direct torque control .......................................................14 Controlling variables .....................................................................14 Comparison of variable speed drives .................................................15 Chapter 3 - Questions and answers ........................................................17 General ............................................................................................17 Performance ....................................................................................18 Operation .........................................................................................24 Chapter 4 - Basic control theory .............................................................28 How DTC works ...............................................................................28 Torque control loop...........................................................................29 Step 1 Voltage and current measurements ....................................29 Step 2 Adaptive motor model .......................................................29 Step 3 Torque comparator and flux comparator .............................30 Step 4 Optimum pulse selector ....................................................30 Speed control ..................................................................................31 Step 5 Torque reference controller .................................................31 Step 6 Speed controller ...............................................................31 Step 7 Flux reference controller ....................................................31 Chapter 5 - Index .....................................................................................32 6 Direct torque control | Technical guide No. 1 Technical guide No. 1 | Direct torque control 9 1 Evolution of direct torque control DC motor drives Figure 1: Control loop of a DC motor drive Features – Field orientation via mechanical commutator – Controlling variables are armature current and field current, measured DIRECTLY from the motor – Torque control is direct In a DC motor, the magnetic field is created by the current through the field winding in the stator. This field is always at right angles to the field created by the armature winding. This condition, known as field orientation, is needed to generate maximum torque. The commutator-brush assembly ensures this condition is maintained regardless of the rotor position. Once field orientation is achieved, the DC motor’s torque is easily controlled by varying the armature current and by keeping the magnetising current constant. The advantage of DC drives is that speed and torque - the two main concerns of the end-user - are controlled directly through armature current: that is the torque is the inner control loop and the speed is the outer control loop (see Figure 1). Advantages – Accurate and fast torque control – High dynamic speed response – Simple to control Initially, DC drives were used for variable speed control because they could easily achieve a good torque and speed response with high accuracy. 10 Direct torque control | Technical guide No. 1 A DC machine is able to produce a torque that is: – Direct - the motor torque is proportional to the armture current: the torque can thus be controlled directly and accurately. – Rapid - torque control is fast; the drive system can have a very high dynamic speed response. Torque can be changed instantaneously if the motor is fed from an ideal current source. A vol tage fed dr ive st i l l has a fast response, since this is determined only by the rotor’s electrical t ime constant ( ie, the total inductance and resistance in the armature circuit) – Simple - f ield orientation is achieved using a simple mechanical device called a commutator/brush assembly. Hence, there is no need for complex electronic control circuitry, which would increase the cost of the motor controller. Drawbacks – Reduced motor reliability – Regular maintenance – Motor costly to purchase – Needs encoder for feedback The main drawback of this technique is the reduced reliability of the DC motor; the fact that brushes and commutators wear down and need regular servicing; that DC motors can be costly to purchase; and that they require encoders for speed and posi- tion feedback. While a DC drive produces an easily controlled torque from zero to base speed and beyond, the motor’s mechanics are more complex and require regular maintenance. AC drives - Introduction – Small size – Robust – Simple in design – Light and compact – Low maintenance – Low cost The evolution of AC variable speed drive technology has been partly driven by the desire to emulate the performance of the DC drive, such as fast torque response and speed accuracy, while utilising the advantages offered by the standard AC motor. Evolution of direct torque control Technical guide No. 1 | Direct torque control 11 1 AC drives - Frequency control using PWM Figure 2: Control loop of an AC drive with frequency control using PWM Features – Controlling variables are voltage and frequency – Simulation of variable AC sine wave using modulator – Flux provided with constant V/f ratio – Open-loop drive – Load dictates torque level Unlike a DC drive, the AC drive frequency control technique uses parameters generated outside of the motor as controlling variables, namely voltage and frequency. Both voltage and frequency reference are fed into a modulator which simulates an AC sine wave and feeds this to the motor’s stator windings. This technique is called pulse width modulation (PWM) and utilises the fact that there is a diode rectifier towards the mains and the intermediate DC voltage is kept constant. The inverter controls the motor in the form of a PWM pulse train dictating both the voltage and frequency. Significantly, this method does not use a feedback device which takes speed or position measurements from the motor’s shaft and feeds these back into the control loop. Such an arrangement, without a feedback device, is called an “open-loop drive”. Evolution of direct torque control 14 Direct torque control | Technical guide No. 1 AC drives - Direct torque control Figure 4: Control loop of an AC drive using DTC Controlling variables With the revolutionary DTC technology developed by ABB, field orientation is achieved without feedback using advanced motor theory to calculate the motor torque directly and without using modulation. The controlling variables are motor magnetising flux and motor torque. With DTC there is no modulator and no requirement for a ta- chometer or position encoder to feed back the speed or position of the motor shaft. DTC uses the fastest digital signal processing hardware avail- able and a more advanced mathematical understanding of how a motor works. The result is a drive with a torque response that is typically 10 times faster than any AC or DC drive. The dynamic speed ac- curacy of DTC drives will be 8 times better than any open loop AC drives and comparable to a DC drive that is using feedback. DTC produces the first “universal” drive with the capability to perform like either an AC or DC drive. The remaining sections in this guide highlight the features and advantages of DTC. Evolution of direct torque control Technical guide No. 1 | Direct torque control 15 1 Comparison of variable speed drives Let us now take a closer look at each of these control blocks and spot a few differences. Figure 1: Control loop of a DC drive Figure 2: Control loop with frequency control Figure 3: Control loop with flux vector control Figure 4 Control loop of an AC drive using DTC The first observation is the similarity between the control block of the DC drive (Figure 1) and that of DTC (Figure 4). Both are using motor parameters to directly control torque. But DTC has added benefits including no feedback device is used; all the benefits of an AC motor (see page 10); and no external excitation is needed. Table 1: Comparison of control variables Evolution of direct torque control 16 Direct torque control | Technical guide No. 1 As can be seen from table 1, both DC drives and DTC drives use actual motor parameters to control torque and speed. Thus, the dynamic performance is fast and easy. Also with DTC, for most applications, no tachometer or encoder is needed to feed back a speed or position signal. Comparing DTC (Figure 4) with the two other AC drive control blocks (Figures 2 & 3) shows up several differences, the main one being that no modulator is required with DTC. With PWM AC drives, the controlling variables are frequency and voltage which need to go through several stages before being applied to the motor. Thus, with PWM drives control is handled inside the electronic controller and not inside the motor. Evolution of direct torque control Technical guide No. 1 | Direct torque control 19 1 – Motor static speed accuracy: - Error between speed ref- erence and actual value at constant load. For DTC, speed accuracy is 10 percent of the motor slip, which with an 11 kW motor, equals 0.3 percent static speed accuracy. With a 110 kW motor, speed accuracy is 0.1 percent without en- coder (open-loop). This satisfies the accuracy requirement or 95 percent of industrial drives applications. However, for the same accuracy from DC drives an encoder is needed. In contrast, with frequency controlled PWM drives, the static speed accuracy is typically between 1 to 3 percent. So the potential for customer process improvements is sig- nificantly higher with standard drives using DTC technology. A DTC drive using an encoder with 1024 pulses/revolution can achieve a speed accuracy of 0.01 percent. – Dynamic speed accuracy: - Time integral of speed devia- tion when a nominal (100 percent) torque speed is applied. DTC open-loop dynamic speed accuracy is between 0.3 to 0.4%sec. This depends on the gain adjustment of the controller, which can be tuned to the process requirements. With other open-loop AC drives, the dynamic accuracy is eight times less and in practical terms around 3%sec.If we furnish the DTC controller with an encoder, the dynamicspeed accu- racy will be 0.1%sec, which matches servo drive performance. What are the practical benefits of these performance figures? – Fast torque response: - This significantly reduces the speed drop time during a load transient, bringing much improved process control and a more consistent product quality. – Torque control at low frequencies: - This is particularly- beneficial to cranes or elevators, where the load needs to be started and stopped regularly without any jerking. Also with a winder, tension control can be achieved from zero through to maximum speed. Compared to PWM flux vector drives, DTC brings the cost saving benefit that no tachometer is needed. – Torque linearity: - This is important in precision applications like winders, used in the paper industry, where an accurate and consistent level of winding is critical. – Dynamic speed accuracy: - After a sudden load change, the motor can recover to a stable state remarkably fast. Questions and answers 20 Direct torque control | Technical guide No. 1 Table 2: Dynamic performance features and benefits offered by DTC technology Apart from excellent dynamic performance figures, are there any other benefits of DTC drive technology? Yes, there are many benefits. For example, DTC drives do not need a tachometer or encoder to monitor motor shaft speed or position in order to achieve the fastest torque response ever from an AC drive. This saves initial cost. Investment cost savings. Increased reliability. Better process control. Higher product quality. Leads to a true universal drive. Similar performance to DC but without tachometer. Reduced mechanical failures for machinery. Less downtime. Lower investment. Cost effective, high performance torque drive; provides position control and better static accuracy. High accuracy control with standard AC motor. Investment cost saving. Better load control. Can use AC drive and motor instead of DC. Standard AC motor means less maintenance and lower cost. Allows speed to be controlled better than 0.5 percent accuracy. No tachometer needed in 95 percent of all applications. Drive for demanding applications. Allows required torque at all times. Torque repeatability 1 percent. Torque response time less than 5ms. No mechanical brake needed. Smooth transition between drive and brake. Allows drive to be used in traditional DC drive applications. Servo drive performance. Good motor speed accuracy without tachometer. Excellent torque control without tachometer. Control down to zero speed and position with encoder. Full torque at zero speed with or without tachometer/ encoder. FEATURE RESULT BENEFIT Questions and answers Technical guide No. 1 | Direct torque control 21 1 Rapid control DC link voltage. Power loss ride through. Drive will not trip. Less down time. Avoids process interruptions. Less waste in continuous process. Automatic start (Direct restart). Starting with motor residual inductance present. No restarting delay required. Can start into a motor that is running without waiting for flux to decay. Can transfer motor from line to drive. No restart. No interruptions on process. Controlled braking between two speed points. Investment cost savings. Better process control. No delay required as in DC braking. Can be used for decelerating to other than zero speed. Reduced need for brake chopper and resistor. Flux braking. Flux optimization. Motor losses minimised. Less motor noise. Controlled motor. Self identification/ Auto-tuning. Tuning the motor to drive for top performance. Easy and accurate setup. No parameter tuning required. Less commissioning time. Guaranteed starting torque. Easy retrofit for any AC system. No predetermined switching pattern of power devices. Low noise. No fixed carrier, therefore acoustic noise reasonable due to “white” noise spectrum. Cost savings in acoustic barriers in noise sensitive applications. No harmful mechanical resonances. Lower stresses in gearboxes, fans, pumps. Can accelerate and decelerate in quickest time possible without mechanical constraints. Automatic start (Flying start). Synchronises to rotating motor. No process interruptions. Smooth control of machinery. Resume control in all situations. No limits on maximum acceleration and deceleration rate. Better process control. BENEFITFEATURE RESULT Table 3: User features and benefits offered by DTC technology Questions and answers 24 Direct torque control | Technical guide No. 1 Operation What is the difference between DTC and traditional PWM methods? – Frequency control PWM and flux vector PWM Traditional PWM drives use output voltage and output fre- quency as the primary control variables but these need to be pulse width modulated before being applied to the motor. This modulator stage adds to the signal processing time and therefore l imits the level of torque and speed response possible from the PWM drive. Typically, a PWM modulator takes 10 times longer than DTC to respond to actual change. – DTC control DTC allows the motor’s torque and stator flux to be used as primary control variables, both of which are obtained directly from the motor itself. Therefore, with DTC, there is no need for a separate voltage and frequency controlled PWM modulator. Another big advantage of a DTC drive is that no feedback device is needed for 95 percent of all drive applications. Why does DTC not need a tachometer or position encoder to tell it precisely where the motor shaft is at all times? There are four main reasons for this: – The accuracy of the motor model (see page 29). – Controlling variables are taken directly from the motor (see page 29). – The fast processing speeds of the DSP and optimum pulse selector hardware (see page 30). – No modulator is needed (see page 14). Questions and answers Technical guide No. 1 | Direct torque control 25 1 When combined to form a DTC drive, the above features pro- duce a drive capable of calculating the ideal switching voltages 40,000 times every second. It is fast enough to control individual switching pulses. Quite simply, it is the fastest ever achieved. Once every 25 microseconds, the inverter’s semiconductors are supplied with an optimum switching pattern to produce the required torque. This update rate is substantially less than any time constants in the motor. Thus, the motor is now the limiting component, not the inverter. What is the difference between DTC and other sensorless drives on the market? There are vast differences between DTC and many of the sensor- less drives. But the main difference is that DTC provides accurate control even at low speeds and down to zero speed without encoder feedback. At low frequencies the nominal torque step can be increased in less than 1ms. This is the best available. How does a DTC drive achieve the performance of a servo drive? Quite simply because the motor is now the limit of performance and not the drive itself. A typical dynamic speed accuracy for a servo drive is 0.1%s. A DTC drive can reach this dynamic accuracy with the optional speed feedback from a tachometer. How does DTC achieve these major improvements over traditional technology? The most striking difference is the sheer speed by which DTC operates. As mentioned above, the torque response is the quickest available. To achieve a fast torque loop, ABB has utilised the latest high speed signal processing technology and spent 100 man years developing the highly advanced motor model which precisely simulates the actual motor parameters within the controller. For a clearer understanding of DTC control theory, see page 28. Questions and answers 26 Direct torque control | Technical guide No. 1 Does a DTC drive use fuzzy logic within its control loop? No. Fuzzy logic is used in some drives to maintain the accelera- tion current within current limits and therefore prevent the drive from tripping unnecessarily. As DTC is controlling the torque directly, current can be kept within these limits in all operating conditions. A drive using DTC technology is said to be tripless. How has this been achieved? Many manufacturers have spent years trying to avoid trips during acceleration and deceleration and have found it extraordinarily difficult. DTC achieves tripless operation by controlling the actual motor torque. The speed and accuracy of a drive which relies on computed rather than measured control parameters can never be realistic. Unless you are looking at the shaft, you are not getting the full picture. Is this true with DTC? DTC knows the full picture. As explained above, thanks to the so- phistication of the motor model and the ability to carry out 40,000 calculations every second, a DTC drive knows precisely what the motor shaft is doing. There is never any doubt as to the motor’s state. This is reflected in the exceptionally high torque response and speed accuracy figures quoted on pages 18 and 19. Unlike traditional AC drives, where up to 30 percent of all switch- ings are wasted, a drive using DTC technology knows precisely where the shaft is and so does not waste any of its switchings. DTC can cover 95 percent of all industrial applications. The exceptions, mainly applications where extremely precise speed control is needed, will be catered for by adding a feedback de- vice to provide closed loop control. This device, however, can be simpler than the sensors needed for conventional closed loop drives. Even with the fastest semiconductors some dead time is introduced. Therefore, how accurate is the auto-tuning of a DTC drive? Auto-tuning is used in the initial identification run of a DTC drive (see page 29). The dead time is measured and is taken into ac- count by the motor model when calculating the actual flux. If we compare to a PWM drive, the problem with PWM is in the range 20 to 30 Hz which causes torque ripple. Questions and answers Technical guide No. 1 | Direct torque control 29 1 Torque control loop Step 1 Voltage and current measurements In normal operation, two motor phase currents and the DC bus voltage are simply measured, together with the inverter’s switch positions. Step 2 Adaptive motor model The measured information from the motor is fed to the Adaptive motor model. The sophistication of this motor model allows precise data about the motor to be calculated. Before operating the DTC drive, the motor model is fed information about the motor, which is collected during a motor identification run. This is called auto-tuning and data such as stator resistance, mutual inductance and saturation coefficients are determined along with the motor’s inertia. The identification of motor model parameters can be done without rotating motor shaft. This makes it easy to apply DTC technol- ogy also in retrofits. The extremely fine tuning of motor model is achieved when the identification run also includes running the motor shaft for some seconds. There is no need to feed back any shaft speed or position with tachometers or encoders if the static speed accuracy require- ment is over 0.5 percent, as it is for most industrial applications. Basic control theory 30 Direct torque control | Technical guide No. 1 This is a significant advance over all other AC drive technology. The motor model is, in fact, key to DTC’s unrivalled low speed performance. The motor model outputs control signals which directly represent actual motor torque and actual stator flux. Also shaft speed is calculated within the motor model. Step 3 Torque comparator and flux comparator The information to control power switches is produced in the torque and flux comparator. Both actual torque and actual flux are fed to the comparators where they are compared, every 25 microseconds, to a torque and flux reference value. Torque and flux status signals are cal- culated using a two level hysteresis control method. These signals are then fed to the optimum pulse selector. Step 4 Optimum pulse selector Within the optimum pulse selector is the latest 40 MHz digital signal processor ( DSP) together with ASIC hardware to determine the switching logic of the inverter. Furthermore, all control signals are transmitted via optical links for high speed data transmission. This configuration brings immense processing speed such that every 25 microseconds the inverter’s semiconductor switching devices are supplied with an optimum pulse for reaching, or maintaining, an accurate motor torque. The correct switch combination is determined every control cycle. There is no predetermined switching pattern. DTC has been referred to as “just-in-time” switching, because, unlike traditional PWM drives where up to 30 percent of all switch changes are unnecessary, with DTC each and every switching is needed and used. This high speed of switching is fundamental to the success of DTC. The main motor control parameters are updated 40,000 times a second. This allows extremely rapid response on the shaft and is necessary so that the motor model (see step 2) can update this information. It is this processing speed that brings the high performance fig- ures including a static speed control accuracy, without encoder, of ±0.5 percent and the torque response of less than 2 ms. Basic control theory Technical guide No. 1 | Direct torque control 31 1 Speed control Step 5 Torque reference controller Within the torque reference controller, the speed control output is limited by the torque limits and DC bus voltage. It also includes speed control for cases when an external torque signal is used. The internal torque reference from this block is fed to the torque comparator. Step 6 Speed controller The speed controller block consists both of a PID controller and an acceleration compensator. The external speed reference signal is compared to the actual speed produced in the motor model. The error signal is then fed to both the PID controller and the acceleration compensator. The output is the sum of outputs from both of them. Step 7 Flux reference controller An absolute value of stator flux can be given from the flux refer- ence controller to the flux comparator block. The ability to control and modify this absolute value provides an easy way to realise many inverter functions such as flux optimization and flux brak- ing (see page 21). Basic control theory 34 Direct torque control | Technical guide No. 1 Contact us 3A FE 58 05 66 85 R E V C E N 6 .6 ..2 01 1 #1 57 00For more information please contact your local ABB representative or visit: www.abb.com/drives www.abb.com/drivespartners © Copyright 2011 ABB. All rights reserved. Specifications subject to change without notice. Technical guide No. 2 | EU Council Directives 3 © Copyright 2013 ABB. All rights reserved. Specifications subject to change without notice. 3AFE61253980 REV E 8.2.2013 Technical guide No. 2 EU Council Directives and adjustable speed electrical power drive systems 2 4 EU Council Directives | Technical guide No. 2 Technical guide No. 2 | EU Council Directives 5 2 Contents Chapter 1 - Introduction ............................................................................9 This guide’s purpose...........................................................................9 How to use this guide .......................................................................10 Responsibilities and actions .........................................................10 Tickboxes ....................................................................................10 Cross-referencing ........................................................................10 Chapter 2 - General questions and answers............................................11 What are these EU Council Directives? ..............................................11 How does EMC affect me? ...............................................................11 What is EMC? ..................................................................................11 What is an electromagnetic environment? ..........................................12 How does electromagnetic interference show up? .............................12 What emissions can drives cause? ....................................................12 How is this emission seen? ...............................................................13 How do I avoid electromagnetic interference? ....................................13 Drives manufacturers must comply with EMC standards then? ...........13 If a drive is CE marked, I need not worry. True? ..................................13 Chapter 3 - CE marking ...........................................................................15 What is CE marking and how relevant is it for drives? .........................15 What is CE marking for? ...............................................................15 Is CE marking a quality mark? ......................................................16 What is the legal position regarding CE marking? ..........................16 What is the importance of CE marking for purchasers of drives? ....16 If I buy a CE marked drive, will I meet the technical requirements of the directives? .........................................................................16 What happens if, as an end-user, I put together a system - do I have to put CE marking on? ..................................................17 What about spare parts that I buy for a drive? Do I negate the CE mark if I replace a component? .......................17 If drives are classed as components, on subassemlies they cannot be EMC certified or carry a CE mark. Is this true? ..............17 In summary ......................................................................................18 Components or subassemblies intended for incorporation into an apparatus by the end users ..........................................................18 Components or subassemblies intended for incorporation into an apparatus by the other manufacturer or assembler ........................18 Finished appliance .......................................................................19 Finished appliance intended for the end users ...............................19 Finished appliance intended for the other manufacturer or assembler 19 Systems (Combination of finished appliances) ...............................19 8 EU Council Directives | Technical guide No. 2 Technical guide No. 2 | EU Council Directives 9 2 Chapter 1 - Introduction This guide’s purpose The aim of this Technical guide No. 2* is to give a straight-forward explanation of how the various EU Council Directives relate to power drive systems (PDSs). For an explanation of the terminolo- gy of PDSs, see pages 21 and 22. While Electromagnetic Compatibility (EMC) is the subject of most concern within the industry, it must be realised that the EMC Directive is only part of the overall EU initiative on common safety standards. It is the intention of this guide to offer users of AC or DC power drive systems - whether machine builders, system designers, distributors, OEMs, end-users or installers - some clear practical guidelines and courses of action. *Notes 1 The content of this technical guide is ABB Oy’s, Drives in- terpretation of events as of July 2007. However, we reserve the right to develop and evolve these interpretations as more details become available from notified bodies (see chapter 6), competent authorities (see chapter 6), organisations and from our own tests. 2 Other technical guides available in this series include: Technical guide No. 1 - Direct torque control (3AFE58056685) Technical guide No. 3 - EMC compliant installation and configuration for a power drive system (3AFE61348280) Technical guide No. 4 - Guide to variable speed drives (3AFE61389211) Technical guide No. 5 - Bearing currents in modern AC drive systems (3AFE64230247) Technical guide No. 6 - Guide to harmonics with AC drives (3AFE64292714) Technical guide No. 7 - Dimensioning of a drive system (3AFE64362569) 10 EU Council Directives | Technical guide No. 2 Introduction Technical guide No. 8 - Electrical braking (3AFE64362534) Technical guide No. 9 - Guide to motion control drives (3AFE68695201) Technical guide No. 10 - Functional safety (3AUA0000048753) How to use this guide The guide is divided into 7 sections. Section 4 looks at purchasing decisions for PDSs. Please note the following about the structure of this section: Responsibilities and actions Each type of purchaser is offered an explanation of their respon- sibilities. This is for awareness. No action is needed. Following the responsibilities is a set of actions. If the purchaser follows these actions, step-by-step, then conforming to the relevant directives will be straightforward. Tickboxes Alongside the actions are tickboxes. Purchasers can photocopy the relevant pages and use them as a checklist with each item being ticked off as it is achieved. Cross-referencing Because of the complexity of conforming to each directive, this guide inevitably carries a lot of cross-references to other sec- tions. In the margin you will come across: Defined on page XX You are advised to turn to the page number reference. You will also notice other references within the text. These can be referred to if the item is unclear but is not essential for achiev- ing compliance. Key point: Within the text you will see: Key point These are key observations that must be observed. Technical guide No. 2 | EU Council Directives 13 2 General questions and answers How is this emission seen? The main emission is via conduction to the mains. Radiation from the converter and conducting cables is another type of emission and it is especially demanding to achieve the radiated emission limits. How do I avoid electromagnetic interference? You need to ensure two things: – that the equipment generates minimum emission. – that the equipment is immune to outside effects. Key point: In the case of power drive systems, a lot depends on the quality of the installation. Electromagnetic interference needs to be conducted to earth (ground potential) and no system can work unless it is properly grounded. Drives manufacturers must comply with EMC standards then? Unfortunately, the process is not that simple. Virtually everyone in the supply chain has a responsibility to ensure a product, a system and an installation complies with the essential require- ments of the EMC Directive. The key is to clearly understand who has responsibility for what. In the forthcoming pages we take a look at various types of purchasers and examine the steps each should take to meet all three directives mentioned on page 11. Everyone from manufacturer to installer to user has a responsi- bility in complying with EMC rules. If a drive is CE marked, I need not worry. True? Again this is a big misconception. Just because a drive has CE marking does not necessarily mean it meets the EMC Directive. 14 EU Council Directives | Technical guide No. 2 Key point: This will all become clear by referring to the section purchasing decisions for PDSs, page 21. CE marking according to the EMC Directive cannot normally be applied to a module that is no more than a chassis with exposed terminals. General questions and answers Technical guide No. 2 | EU Council Directives 15 2 Chapter 3 - CE marking What is CE marking and how relevant is it for drives? CE marking, shown below, is the official signature of the Dec- laration of conformity (see pages 43 and 44) as governed by the European Commission. It is a very specific graphic symbol and must be separated from other marks. CE marking is a system of self certification to identify equipment that complies with the relevant applicable directives. If a drive is the subject of several directives and, for example, conforms with the Low Voltage Directive (see page 56), then, from 1997, it is compulsory that it shows CE marking. That marking shall indicate that the drive also conforms to the EMC Directive (page 57). CE marking shall indicate conformity only to the directive(s) applied by the manufacturer. Key point: NOTE: There must be technical documentation supporting the Declaration of conformity. For more on technical documentation, please refer to pages from 36 to 40. What is CE marking for? CE marking is mainly for the benefit of authorities throughout the EU and EEA countries who control the movement of goods. CE marking shows that the product complies with the essential requirements of all relevant directives, mainly in the area of techni- cal safety, compatibility issues and conformity assessment. There are three directives that are relevant to drives, but CE marking may be attached to indicate compliance with one of them only (see the previous page). 18 EU Council Directives | Technical guide No. 2 In summary The EMC Directive defines equipment as any apparatus or fixed installation. As there are separate provisions for apparatus and fixed installations, it is important that the correct category of the equipment is determined. In technical-commercial classifications the following terminol- ogy is frequently used: components, sub-assemblies, finished appliances (ie, finished products), a combination of finished appliances (ie, a system), apparatus, fixed installations and equipment. The key issue here is whether the item to be considered is for end users or not: – If it is meant for end users, the EMC directive applies – If it is meant for manufacturers or assemblers, the EMC direc- tive does not apply Components or subassemblies intended for incorporation into an apparatus by the end users A manufacturer may place components or sub-assemblies on the market which are: – For incorporation into an apparatus by the end-user, – Available to end users and likely to be used by them. These components or sub-assemblies are to be considered as apparatus with regard to the application of the EMC. The instruc- tions for use accompanying the component or sub-assembly should include all relevant information, and should assume that adjustments or connections can be performed by an end-user not aware of the EMC implications. Some variable speed power drive products fall into this category, eg, a drive with enclosure and sold as a complete unit (CDM) to the enduser who installs it into his own system. All provisions of the EMC Directive will apply (CE mark, Declaration of conformity and technical documentation). Components or subassemblies intended for incorporation into an apparatus by the other manufacturer or assembler Components or sub-assemblies intended for incorporation into an apparatus or an other sub-assembly by other manufacturers or assemblers are not considered to be “apparatus” and are therefore not covered by the EMC Directive. These components include resistors, cables, terminal blocks, etc. CE marking Technical guide No. 2 | EU Council Directives 19 2 Some variable speed power drive products fall into this category as well, eg, basic drive module (BDM). These are meant to be assembled by a professional assembler (eg, panel builder or system manufacturer) into a cabinet not in the scope of delivery of the manufacturer of the BDM. According to the EMC Directive, the requirement for the BDM supplier is to provide instructions for installation and use. Note: The manufacturer or assembler of the panel or system is re- sponsible for CE mark, Declaration of conformity and technical documentation. Finished appliance A finished appliance is any device or unit containing electrical and/or electronic components or sub-assemblies that delivers a function and has its own enclosure. Similarly than components, the interpretation finished appliance can be divided into two categories: it can be intended for the end users, or for the other manufacturers or assemblers. Finished appliance intended for the end users A finished appliance is considered as apparatus in the sense of the EMC Directive, if it is intended for the end-user and thus has to fulfill all the applicable provisions of the Directive. Finished appliance intended for the other manufacturer or assembler When the finished appliance is intended exclusively for an in- dustrial assembly operation for incorporation into other appa- ratus, it is not an apparatus in the sense of the EMC Directive and consequently the EMC Directive does not apply for such finished appliances. Systems (Combination of finished appliances) A combination of several finished appliances which is combined, and/or designed and/or put together by the same person (ie, the system manufacturer) and is intended to be placed on the market for distribution as a single functional unit for an end-user and intended to be installed and operated together to perform a specific task. All provisions of the EMC Directive, as defined for apparatus, apply to the combination as a whole. CE marking 20 EU Council Directives | Technical guide No. 2 CE marking Apparatus Apparatus means any finished appliance or combination thereof made commercially available (ie, placed on the market) as a single functional unit, intended for the end-user, and liable to generate electromagnetic disturbance, or the performance of which is liable to be affected by such disturbance. Fixed installation A particular combination of several types of apparatus, equip- ment and/or components, which are assembled, installed and intended to be used permanently at a predefined location. Equipment Any apparatus or fixed installation Technical guide No. 2 | EU Council Directives 23 To make this technical guide easy to use, we have also identified certain types of people who will be involved in the purchasing of drives. Please identify the type nearest to your job function and turn to the relevant section Continued overleaf... 2 Purchasing decisions for PDSs WHO ARE YOU? 25 IF THIS IS YOU, TURN NOW TO PAGE... Machine builder is a person who buys either a PDS, CDM or BDM and other mechanical or electrical component parts, such as a pump, and assembles these into a machine. Note: A machine is defined as an assembly of linked parts or components, at least one of which moves. It includes the appropriate actuators, control and power circuits joined together for a specific application, in particular for processing, treatment, moving or packaging of a material. System designer carries out all the electrical design of the power drive system, specifying all component parts which comprise a PDS. End-user is the final customer who will actually use the machine, PDS or CDM/BDM. Panel builder constructs enclosures into which a panel builder will install a variety of components, including a CDM/BDM and sometimes the motor. However, the built enclosure does not constitute a machine. 28 31 32 24 EU Council Directives | Technical guide No. 2 Panel builder - page 32 Distributor - page 34 System designer - page 28 Panel builder - page 32 Machine builder or OEM - page 25 Installer - page 35 Installer - page 35 Purchasing decisions for PDSs End-user - page 31 Drive manufacturer WHO ARE YOU? IF THIS IS YOU, TURN NOW TO PAGE... 25 28 32 Distributor acts as the sales distribution channel between the CDM/ BDM manufacturer and the end-user, machine builder, OEM, panel builder or system designer. Installer carries out the entire electrical installation of the PDS. Original equipment manufacturer ( OEM) For the purposes of purchasing drives, an OEM will normally fall into the category of a machine builder, system designer or panel builder. Therefore, if you identify yourself as an OEM, refer to the relevant pages for each of these job functions. 35 34 Technical guide No. 2 | EU Council Directives 25 2 NOTE: Before reading this section we strongly urge you to familiarise yourself with the terms explained on pages 21-24. If you are a machine builder buying a PDS... ...You have the following responsibilities: 1. Because you are building a complete machine, which in- cludes coupling up the motors to the PDS and providing the mechanical guarding and so on, you are liable for the total mechanical and electrical safety of the machine as specified in the Machinery Directive. Therefore, the PDS is ultimately your responsibility. You need to ensure that the entire PDS meets the Machinery Directive. Only then can CE marking be applied to the whole machine. 2. You are also responsible for the electrical safety of all parts of the PDS as specified in the Low Voltage Directive. 3. You must ensure electrical equipment and components are manufactured in accordance with the EMC Directive. The manufacturer of these parts is responsible for EMC for that particular part. Nevertheless you are responsible for EMC for the machine. You may choose electrical parts not in accord- ance with the EMC directive, but then you have the respon- sibility for compliance of parts. Note: Be aware that combining CE marked sub-assemblies may not automatically produce an apparatus that meets the requirements. 4. You must ensure that the PDS or its component parts carry declarations of conformity in accordance with the electrical safety requirements of the Low Voltage Directive. 5. You must be able to assure an authority and customers that the machine has been built according to the Machinery Directive, the Low Voltage Directive and the EMC Direc- tive. It may be necessary to issue technical documentation to demonstrate compliance. You must keep in mind that you and only you have responsibility for compliance with directives. 6. A Declaration of conformity according to the directives above must be issued by the machine builder and CE marking must then be affixed to the machine or system. 7. Any machine that does not comply must be withdrawn from the market. Purchasing decisions for PDSs 28 EU Council Directives | Technical guide No. 2 3. Pass this technical documentation to a notif ied body. The machine builder SHOULD NOT pass the file on to an end-user. Based on the technical documentation, obtain a Certificate of Adequacy or technical report from a notified body. Defined on pages 43, 45 and 46 4. Issue a Declaration of conformity for the entire machine. Only then can you apply CE marking. 5. Pass the Declaration of conformity related to all three directives on to the end-user of the machine. 6. Apply CE marking to the machine. 7. Congratulations! You have successfully complied with the main requirements for safe and efficient operation of a machine. If you are a system designer You have the following responsibilities: 1. The PDS is a complex component of the machine. Therefore, the Machinery Directive has to be complied with by issuing a Declaration of incorporation. 2. Because a PDS is not a machine, the only directives which need to be complied with are the Low Voltage Directive and the EMC Directive. 3. The responsibility for Declaration of conformity and apply- ing CE marking rests with both the system designer and the supplier of the component parts which make up the power drive system. The system designer has to decide if he is going to place his delivery on the market as a single functional unit or not – if the answer is YES, the delivery shall be classified as a system. – if the answer is NO, the delivery shall be classified as an installation. Purchasing decisions for PDSs Technical guide No. 2 | EU Council Directives 29 2 A. If the delivery is classified as a system, the system designer has to choose one of two paths to follow: Path 1 All components have EMC compliance 1. EMC behaviour is based on a component’s performance. 2. Responsibility lies with the component suppliers for CE marking of individual complex components 3. PDS is an system according to the EMC Directive (as placed on the market as a single functional unit). 4. The Declaration of conformity as well as the instructions for use must refer to the system as whole. The system designer assumes responsibility for compliance with the Directive. Note 1: The system designer is responsible for producing the instructions for use for the particular system as whole. Note 2: Be aware that combining two or more CE marked sub- assemblies may not automatically produce a system that meets the requirements. 5. No CE marking is required for a system as whole, as long as each part bears the CE mark. Actions you must take 1. Follow all installation guidelines issued by each of the component suppliers. 2. Issue instructions for use in order to operate the system. 3. Issue technical documentation for the system. 4. Issue a Declaration of conformity. 5. DO NOT issue a CE mark. Purchasing decisions for PDSs 30 EU Council Directives | Technical guide No. 2 Path 2 Components without EMC compliance 1. EMC behaviour is designed at the system level (no accumulated cost by device specific filters etc). 2. Responsibility lies with the system designer who decides the configuration (place or a specific filter, etc). 3. PDS is a system according to the EMC Directive (as placed on the market as a single functional unit). 4. Declaration of conformity and CE marking are required for the system. Actions you must take 1. Follow the installation guidelines issued by each of the component suppliers. 2. Optimise the construction of the installation to ensure the design meets the required EMC behaviour, ie, the location of filters. Defined on pages 36 - 46 3. Issue instructions for use in order to operate the system. 4. Issue technical documentation for the system. 5. Issue a Declaration of conformity and CE mark. B. If the delivery is an installation, the system designer has one path to follow: All components have EMC compliance 1. EMC behaviour is based on a component’s performance. 2. Responsibility lies with the component suppliers for CE marking of individual complex components. 3. PDS is an installation according to the EMC Directive. 4. No Declaration of conformity or CE marking is required for a fixed installation, (such as an outside broadcast radio station) DOC and CE marking are needed. Purchasing decisions for PDSs Technical guide No. 2 | EU Council Directives 33 2 4. If you choose to assess yourself you must make reference to EMC Directives: 2004/108/EC And to harmonised standard: EN 61800-3 And you must make reference to LVD Directive: 2006/95/EC And corresponding harmonized standard: EN 61800-5-1 or EN 50178 5. Once testing is completed, the results need to be included in the technical documentation ( TD) for the panel. 6. Technical documentation shall be assessed by youself in order to demonstrate compliance. You may use Notified Body for assessment as well. 7. You must then issue the Declaration of conformity and CE marking for the panel. Option B - To buy CE marked components Option B - Actions to meet these responsibilities 1. Buying CE marked components creates a system or an apparatus (refer to page 17-20) depending on the nature of the panel. 2. Although the panel builder does not have to carry out tests, he must ensure he conforms to the installation guidelines given by each of the component manufacturers. Note: Be aware that combining two or more CE- marked components may not automatically produce a system, which meets the requirements. 3. Beware! These guidelines could differ greatly from those given for normal installation purposes because the components will be in close proximity to each other. 4. Issue instructions for use in order to operate the system or apparatus. Purchasing decisions for PDSs 34 EU Council Directives | Technical guide No. 2 5. Issue technical documentation. 6. Issue a Declaration of conformity. 7. Apply CE marking to your panel in the case of an apparatus. In the case of a system DO NOT apply CE marking. Additional actions The panel can be either sold on the open market or use as part of a machine. For each option there is a different requirement: 1. If you know that the panel is to be used as part of a machine then you must request from the CDM / BDM manufacturer a Declaration of incorporation. 2. The Declaration of incorporation must be supplied with the panel to the machine builder, but CE marking based on Machinery Directive MUST NOT be affixed. This is because CE marking always needs a Declaration of conformity. Key point: The Declaration of incorporation CAN NOT be used to apply CE marking. 3. The machine builder will need this Declaration of incorporation because he has to construct a technical documentation ( TD) for the machine and in that file all the declarations need to be included. If you are a distributor buying a CDM/ BDM... ...You have the following responsibilities: 1. If a distributor is selling boxed products, like CDMs and BDMs (drives), direct from the manufacturer, his only responsibility is to pass on the installation guidelines to the end-user, ma- chine builder or system designer. In addition, the Declara- tion of conformity must be passed to the machine builder or system designer. 2. Both the installation guidelines and the Declaration of conformity are available from the manufacturer. Purchasing decisions for PDSs Technical guide No. 2 | EU Council Directives 35 2 Actions you must take to meet these responsibilities 1. Pass all installation guidelines and declaration of con- formities to either the end-user, machine builder or system designer. If you are an installer buying a CDM/ BDM or PDS... ...You have the following responsibilities: 1. You must ensure that the installation guidelines of the machine builder and/or system designer are adhered to. Actions you must take to meet these responsibilities 1. Follow machinery builder and/or system designer Instal- lation guidelines. 2. See Technical guide No. 3 for recommended installation guidelines. Purchasing decisions for PDSs 38 EU Council Directives | Technical guide No. 2 How to make up a TD 1. Description of the product (Note: You can photocopy these pages and use as a tickbox checklist) i. identification of product a. brand name. b. model number. c. name and address of manufacturer or agent. d. a description of the intended function of the apparatus. e. any limitation on the intended operating environment. ii. a technical description a. a block diagram showing the relationship between the different functional areas of the product. b. relevant technical drawings, including circuit diagrams, assembly diagrams, parts lists, installation diagrams. c. description of intended interconnections with other products, devices, etc. d. description of product variants. 2. Procedures used to ensure product conformity i. details of significant design elements a. design features adopted specifically to address EMC and electrical safety problems. b. relevant component specifications. c. an explanation of the procedures used to control variants in the design together with an explanation of the procedures used to assess whether a particular change in the design will require the apparatus to be re-tested. d. details and results of any theoretical modelling of performance aspects of the apparatus. Terminology Technical guide No. 2 | EU Council Directives 39 2 Terminology e. a list of standards applied in whole or part. f. the description of the solution adopted in order to comply with the directive. ii. test evidence where appropriate a. a list of the EMC and electrical safety tests performed on the product, and test reports relating to them, including details of test methods, etc. b. an overview of the logical processes used to decide whether the tests performed on the apparatus were adequate to ensure compliance with the directive. c. a list of the tests performed on critical sub-assemblies, and test reports or certificates relating to them. 3. If chosen a statement from notified body This will include: i. reference to the exact build state of the apparatus assessed ii. comment on the technical documentation. iii. statement of work done to verify the contents and authenticity of the design information. iv. statement, where appropriate, on the procedures used to control variants, and on environmental, installation and maintenance factors that may be relevant. 4. Actions by the notified body The notified body will study the technical documentation and issue the statement and this should be included in the technical documentation. Note: When compiling the technical documentation you may need all Declarations from suppliers, ie, Declaration of con- formity and Declaration of incorporation depending on the parts, to ensure they carry CE marking. 40 EU Council Directives | Technical guide No. 2 Technical file (for mechanical safety aspects) APPLIED TO: machines and safety components RESPONSIBILITY: machine builder / system designer REQUIRED BY: Machinery Directive What is a technical file? A technical file is the internal design file which should show how and where the standards are met and is all that is needed if self certifying the equipment by the standards compliance route. If a Declaration of incorporation is included in a set of papers and this claims to meet the appropriate parts of the standards and simply instructs the user to meet the standards with other parts of his machine, it is possible to use this as a part of a technical file. How to make up a technical file Drawings and diagrams 1. Overall drawings of the machine. 2. Control circuit diagrams. Health and safety 1. All drawings, calculations and test results used to check the machine’s conformity with essential health and safety require- ments. Machine design 1. Lists of the essential health and safety requirements, harmo- nised standards, other standards and technical specifications used when designing the machine. 2. Description of methods used to eliminate hazards presented by the machine. Other certificates required 1. A technical report or certificate issued by a notified body - if required. 2. A copy of the instructions for the machine. Terminology Technical guide No. 2 | EU Council Directives 43 2 Declaration of conformity (for EMC and electrical safety aspects) APPLIED TO: electrical equipment and electrical equipment of machines RESPONSIBILITY: equipment manufacturer REQUIRED BY: Low Voltage Directive and EMC Directive How to obtain a Declaration of conformity You need to provide the following: 1. a reference to the Directive(s), 2. an identification of the apparatus to which it refers (including name, type and serial number), 3. the name and address of the manufacturer and, where appli- cable, the name and address of his authorised representative in the Community, 4. a dated reference to the specifications under which conformity is declared, 5. the date of the declaration, 6. the identity and signature of the person empowered to bind the manufacturer or his authorised representative. Declaration of conformity (for mechanical safety aspects) APPLIED TO: machines RESPONSIBILITY: machine builder REQUIRED BY: Machinery Directive How to obtain a Declaration of conformity You need to provide the following: 1. business name and full address of the manufacturer or, his authorised representative; 2. name and address of the person authorised to compile the technical file, who must be established in the Community; Terminology 44 EU Council Directives | Technical guide No. 2 3. description and identification of the machinery, including ge- neric denomination, function, model, type, serial number and commercial name; 4. a sentence expressly declaring that the machinery fulfils all the relevant provisions of the machinery Directive 5. where appropriate, the name, address and identification number of the notified body which carried out the EC type- examination and the number of the EC type-examination certificate; 6. where appropriate, the name, address and identification number of the notified body which approved the full quality assurance system; 7. a list to the harmonised standards or the other technical standards and specifications used; 9. the place and date of the declaration as well as the identity and signature of the person empowered to draw up the declaration on behalf of the manufacturer or his authorised representative. Declaration of incorporation APPLIED TO: machines or equipment intended for incorporation into other machinery RESPONSIBILITY: drives manufacturer / machine builder / panel builder REQUIRED BY: Machinery Directive What is a Declaration of incorporation? Drives manufacturers must meet the appropriate parts of the Machinery Directive and provide a Declaration of incorporation which states that the drive does not comply on its own and must be incorporated in other equipment. This declaration will show the standards that have been applied to the parts of the system within the manufacturer’s scope. This declaration includes a statement restricting the user from putting the equipment into service until the machinery into which it is to be incorporated, or of which it is to be a component, has been found, and declared, to be in conformity with the provi- sions of the Machinery Directive and the national implementing legislation, ie, as a whole including the equipment referred to in this declaration. Terminology Technical guide No. 2 | EU Council Directives 45 2 The declaration then lists the standards relating to the Machinery and Low Voltage Directives which the manufacturer has met. It concludes that the entire equipment must meet the provisions of the directive. Quite simply, the manufacturer passes on the responsibility to the machine or system builder. Is there no way out of this type of declaration? No. You must understand that because the manufacturer may be supplying only one part in a machinery, such as the inverter, the manufacturer is legally obliged to ensure that whoever puts the system together must check that it is safe. Only then can the machine or system builder use the Declaration of incorporation in his technical file of the machine. Key point: Most manufacturers will include a Declaration of incorporation covering the Machinery Directive for all built PDS products. What a Declaration of incorporation contains 1. business name and full address of the manufacturer or his authorised representative; 2. description and identification of the partly completed machin- ery including generic denomination, function, model, type, serial number and commercial name; 3. a sentence declaring which essential requirements of the Directive are applied and fulfilled; 4. an undertaking to transmit, in response to a reasoned request by the national authorities, relevant information on the partly completed machinery; 5. a statement that the partly completed machinery must not be put into service until the final machinery into which it is to be incorporated has been declared in conformity with the provi- sions of the Directive; 6. the place and date of the declaration as well as the identity and signature of the person empowered to draw up the declaration on behalf of the manufacturer or his authorised representative. Terminology 48 EU Council Directives | Technical guide No. 2 Chapter 7 - Standards and directives The use of standards is voluntary, but compliance with directives without the use of harmonised standards is extremely difficult. There are two ways to show that a power drive system or part of it conform: – Use of harmonised standards (EN). – By way of a technical documentation when no harmonised standards exist, or if all parts of a harmonised standard can- not be applied. Key point: It is recommended to use technical documentation even when standards are harmonised as it makes it easier to show conform- ity afterwards, if required by authorities. Directive or standard? The legislation of the European Union is defined by different directives. The directives concerning power drive systems are known as new approach directives, which means that they do not include exact figures or limits for products. What they do include is es- sential requirements mainly for health and safety which make the application of the relevant harmonised standards mandatory. The requirements of directives are firmly established in standards. Standards give exact figures and limits for products. The responsibility for defining standards in Europe rests with three committees: CEN, for areas of common safety, CENELEC, for electrical equipment and ETSI, for telecommunications. Harmonised standards for PDSs To remove technical barriers to trade in EU or EEA countries, the standards are harmonised in member states. In the harmonisation procedure, all member states are involved in developing the Committee’s proposals for their own national standard. A standard becomes harmonised when published in the Official Journal of the EU. Technical guide No. 2 | EU Council Directives 49 2 The idea is that if a product conforms to the harmonised standard, it is legally manufactured and when placed onto the market in one country, it must be freely marketed in other member countries. How to recognise a European standard Harmonised standards come in the following format: XX EN 60204-1 where XX = the national prefix (eg BS = UK; SFS = Finland) EN = the abbreviation of Euronorm 60204-1 = an example of a standard number The numbering of European standards follows a well structured and organized sequence: – EN 50225:1996 (the year of availability of the EN is separated from the number by a colon) – EN 50157-2-1:1996 (the part number is indicated by a hy- phen) The first two numerals indicate the origin of the standard: – 40xxx to 44xxx cover domains of common CEN/ CENELEC activities in the IT field – 45xxx to 49xxx cover domains of common CEN/ CENELEC activities outside the IT field – 50xxx to 59xxx cover CENELEC activities, where – EN 50xxx refer to the standards issued by CENELEC only – EN 55xxx refer to the implementation of CISPR documents – 60000 to 69999 refer to the CENELEC implementation of IEC documents with or without changes European standards are adopted and confirmed by CENELEC member countries by adding national prefix before the stand- ard id (for example: SFS-EN 60601-1, DIN EN 60601-1, BS EN 60601-1). There is also some clue as to a standard’s status: prEN 50082-2 = proposal for standard sent to member states ENV 50 = pre-standard which is in force for 3 years to obtain practical experience from member states Standards and Directives 50 EU Council Directives | Technical guide No. 2 Your questions answered Which standards directly relate to drives? At the moment, there are three Product Specific Standards which relate to the compliance with EU directives. They are cal led as “EN 61800-3 Adjustable speed electr ical power dr ive systems - Part 3: EMC requirements and specific test methods”, which relates to EMC Directive, “EN 61800-5-1 Adjustable speed electrical power drive systems - Part 5-1: Safety requirements - Electrical, thermal and energy”, which relates to Low Voltage Directive and EN 61800-5-2 Adjustable speed electrical power drive systems - Part 5-2: Safety requirements - Functional safety”, which relates to Machinery Directive. In addition there are other standards, which need to be taken account: – EN 60204-1, Electrical Equipment of Machines, which, in addition to being a Low Voltage Directive standard for all electrical equipment, is also an electrical safety standard under the Machinery Directive. – EN 50178 according to Low Voltage Directive and – EN 61800-1/2/4, which give rating specifications for Power Drive Systems (LV DC, LV AC and MV AC PDS respectively). – EN 61000-3-2 and EN 61000-3-12, which give requirements for harmonic current caused by equipment What are the issues of EN 61800-3 and drives? For emissions there are two main aspects to be considered: Conducted emissions: these are seen on the power supply cables and will also be measured on the control connections, while radiated emissions are air borne. Conducted emissions at low frequencies are known as harmonics, which have been a familiar problem to many users of a PDS. Where harmonics are concerned EN 61800-3 refers to EN 61000-3-2, which applies for equipment under 16 A per phase. In addition, the harmonics standard EN 61000-3-12 applies up to 75 A per phase. At the moment following groups can be separated – Below 16 A per phase – Professional, over 1kW => No limits. – Other > the limits specified. – Between 16 A and 75 A per phase – Equipment for public low voltage systems => the limits specified. – Equipment for other systems => the limits specified Standards and Directives Technical guide No. 2 | EU Council Directives 53 2 Standards and Directives When a PDS/CDM/BDM is to be incorporated with another product, the resulting EMC behaviour of that product is the responsibility of the assembler of the final product. PDS of category C3: PDS with rated voltage less than 1,000 V, intended for use in the second environment. A PDS (or CDM/BDM) sold “as built” to the end-user or in order to be incorporated into an apparatus, system or installation. Description Placed on the market. Free movement based on compliance with the EMC Directive. The EC Declaration of Conformity and CE Marking are required. The PDS manufacturer is responsible for EMC behaviour of the PDS under specified conditions. Additional EMC measures are described in an easy-to-understand way and can be implemented by a layman. When PDS/CDM is going to be incorporated with another product, the resulting EMC behaviour of that product is the responsibility of the assembler of the final product, by following the manufacturer’s recommendations and guidelines. PDS of category C4: PDS with rated voltage equal to or above 1,000 V, or rated current equal to or above 400 A, or intended for use in com- plex systems in the second environment. A PDS (or CDM/BDM) sold to be incorporated into an ap- paratus, system or installation. Description Category C4 requirements include all other EMC requirements but radio frequency emission. They assessed only when it is installed in its intended location. Therefore category C4 PDS is treated as a fixed installation, and thus has no requirement for EC Declaration of Conformity or CE Marking. The EMC directive requires the accompanying documentation to identify the fixed installation, its electromagnetic compatibility characteristics and responsible person, and to indicate the pre- cautions to be taken in order not to compromise the conformity of that installation. 54 EU Council Directives | Technical guide No. 2 Standards and Directives In order to comply the above requirements in the case of cat- egory C4 PDS (or CDM/BDM), the user and the manufacturer shall agree on an EMC plan to meet the EMC requirements of the intended application. In this situation, the user defines the EMC characteristics of the environment including the whole installation and the neighborhood. The manufacturer of PDS shall provide information on typical emission levels and installation guidelines of the PDS which is to be installed. Resulting EMC behaviour is the responsibility of the installer (eg, by following the EMC plan). Where there are indications of non-compliance of the category C4 PDS after commissioning, the standard includes procedure for measuring the emission limits outside the boundary of an installation. Examples concerning applications of different approaches 1. BDM used in domestic or industrial premises, sold without any control of the application. The manufacturer is responsible that sufficient EMC will be achieved even by a layman. Although the EMC Directive applies to the apparatus and fixed installations only (generally components are excluded), it states that the components which are intended for incorporation into apparatus by the end user and which liable to generate electromagnetic disturbances are included. Thus, if members of the public (end-users) buy a component off the shelf, they will not have to worry about compliance when they fit it to their machine. Therefore, the responsibility for compli- ance and CE Marking such components under EMC lies with the manufacturer. Depending of intended installation location category C1 or C3 equipment is allowed. 2. PDS or CDM/BDM for domestic or industrial purposes, sold to professional assembler. This is sold as a sub-assembly to a professional assembler who incorporates it into a machine, apparatus or system. Condi- tions of use are specified in the manufacturer’s documentation. Exchange of technical data allows optimisation of the EMC solutions. In addition of categories C1 and C3, also category C2 is allowed. 3. PDS or CDM/BDM for use in installations. The conditions of use are specified at the time by the purchase order; consequently an exchange of technical data between sup- plier and client is possible. It can consist of different commercial units (PDS, mechanics, process control etc). Technical guide No. 2 | EU Council Directives 55 2 Standards and Directives The combination of systems in the installation should be con- sidered in order to define the mitigation methods to be used to limit emissions. Harmonic compensation is an evident example of this, both for technical and economical reasons. In addition of categories C1, C2 and C3, also category C4 is allowed. 4. PDS or CDM/BDM for use in machine. PDS or CDM/BDM combined with application device (machine) such as a vacuum cleaner, fan, pump or such like, ie, ready to use apparatus. Similarly inverters (E.Q. subassemblies of BDMs) come under this class of components. On their own they do not have an intrinsic function for the end-user, but are sold to professional installers who incorporate them into a machine, ap- paratus or system. They are not on sale directly to the end-user. Therefore for EMC Directive point of view the PDS/CDM/BDM here is a component which is excluded from the directive. The machine builder is responsible for all EMC issues. The manufac- turer of PDS/CDM/BDM is responsible for providing installation, maintenance and operation instructions to the machine builder in order to achieve compliance with EMC Directive. Nevertheless, it is recommended to use category C1, C2, C3 or C4 PDS/CDM/BDM rather than drives without any compliance. Machinery Directive 98/37/EC How does the Machinery Directive affect my drive? This directive concerns all combinations of mechanically joined components, where at least one part is moving and which have the necessary control equipment and control and power input circuits. The directive concerns all machines but not those like lifts, which have a specific directive. The new machinery Directive 2006/42/EC has been published. Since the old directive 98/37/EC can be used until December 29, 2009, the changes due to the new directive will be consider in the future editions of this Guide.