Cranes. AP02: Cabling and Wiring Guidelines SIMOVERT MASTERDRIVES. Foreword. Introduction. Selection of load side components

Transcription

1 Foreword Introduction 1 Cranes AP02: Cabling and Wiring Guidelines SIMOVERT MASTERDRIVES Product Information Selection of load side components 2 Sizing of cable cross section 3 Power cable selection 4 Installation of control cables 5 Busbar connections (including cable connection) 6 Appendix A 05/2010

2 Legal information Warning notice system This manual contains notices you have to observe in order to ensure your personal safety, as well as to prevent damage to property. The notices referring to your personal safety are highlighted in the manual by a safety alert symbol, notices referring only to property damage have no safety alert symbol. These notices shown below are graded according to the degree of danger. DANGER indicates that death or severe personal injury will result if proper precautions are not taken. WARNING indicates that death or severe personal injury may result if proper precautions are not taken. CAUTION indicates that minor personal injury can result if proper precautions are not taken. NOTICE indicates that property damage can result if proper precautions are not taken. If more than one degree of danger is present, the warning notice representing the highest degree of danger will be used. A notice warning of injury to persons with a safety alert symbol may also include a warning relating to property damage. Qualified Personnel The product/system described in this documentation may be operated only by personnel qualified for the specific task in accordance with the relevant documentation, in particular its warning notices and safety instructions. Qualified personnel are those who, based on their training and experience, are capable of identifying risks and avoiding potential hazards when working with these products/systems. Proper use of Siemens products Note the following: Trademarks WARNING Siemens products may only be used for the applications described in the catalog and in the relevant technical documentation. If products and components from other manufacturers are used, these must be recommended or approved by Siemens. Proper transport, storage, installation, assembly, commissioning, operation and maintenance are required to ensure that the products operate safely and without any problems. The permissible ambient conditions must be complied with. The information in the relevant documentation must be observed. All names identified by are registered trademarks of Siemens AG. The remaining trademarks in this publication may be trademarks whose use by third parties for their own purposes could violate the rights of the owner. Disclaimer of Liability We have reviewed the contents of this publication to ensure consistency with the hardware and software described. Since variance cannot be precluded entirely, we cannot guarantee full consistency. However, the information in this publication is reviewed regularly and any necessary corrections are included in subsequent editions. Siemens AG Industry Sector Postfach NÜRNBERG GERMANY 07/2013 Technical data subject to change Copyright Siemens AG All rights reserved

3 Foreword General Notes Note The standard applications are not binding and do not claim to be complete regarding the circuits shown, equipping and any eventuality. The standard applications do not represent customer-specific solutions. They are only intended to provide support for typical applications. You are responsible in ensuring that the described products are correctly used. These standard applications do not relieve you of the responsibility in safely and professionally using, installing, operating and servicing equipment. When using these standard applications, you recognize that we cannot be made liable for any damage/claims beyond the liability clause described. We reserve the right to make changes to these standard applications at any time without prior notice. If there are any deviations between the recommendations provided in these standard applications and other Siemens publications e. g. catalogs then the contents of the other documents have priority. Guarantee, Liability and Support If the application is provided free of charge the following shall apply: We shall not be liable for the information contained in this document. Any and all further rights and remedies against Siemens AG for whatsoever legal reason, shall be excluded; this shall refer in particular to claims for loss of production, loss of use, loss of orders or profit and other direct, indirect or consequential damage. The aforesaid shall not apply if liability is mandatory, e. g. in accordance with the Product Liability Act, in cases of intent, gross negligence by directors and officers of Siemens AG or in the case of willful hiding of a defect. These limitations of liability shall also apply for the benefit of the Siemens AG's subcontractors, suppliers, agents, directors, officers and employees. This Contract shall be subject to German law if customer s place of business is in Germany. If customer s place of business is outside of Germany the Contract shall be subject to Swiss law. The application of the UN Convention on Contracts for the International Sale of Goods (CISG) shall be excluded. If the application is provided in return for payment the alternative shall apply which fits the respective business case: Product Information, 05/2010 3

4 Foreword Alternative 1: (internal business) If not explicitly stated otherwise below, the "Terms and Conditions for Deliveries and Services for Siemens Internal Transactions", valid at the time of sale, are applicable. Alternative 2: (domestic business of Siemens AG) If not explicitly stated otherwise below, the "General License Conditions for Software Products for Automation and Drives for Customers with a Seat or registered Office in Germany", valid at the time of sale, are applicable. Alternative 3: (direct export business of Siemens AG) If not explicitly stated otherwise below, the "General License Conditions for Software Products for Automation and Drives for Customers with a Seat or Registered Office outside of Germany", valid at the time of sale, are applicable. It is not permissible to transfer or copy these standard applications or excerpts of them in unmodified form without first having prior explicit authorization from Siemens Industry Sector in writing. Export Procedure Indicator AL: N ECCN: N Background Siemens supplies electrical components such as SIMATIC S7 programmable logic controllers, SIMOVERT MASTERDRIVES frequency converters and induction motors as components for installation on cranes in the harbour and other industries. Safe and reliable performance of the electrical components without disturbance or premature failure of electronic components depends on adequate installation and wiring practices. The following chapters describe in detail cabling recommendations by Siemens. Particularly noteworthy are aspects covered in the international standard IEC providing requirements and recommendations relating to the electrical equipment of hoisting machines so as to promote safety of persons and property, consistency of control response and ease of maintenance. IEC Safety of machinery Electrical equipment of machines Part 32: Requirements for hoisting machines EN DIN VDE 0660 EN EN Safety of machinery Safety-related parts of control systems - Part 1: General principles for design Part 12 Protective conductor terminals Limits and methods of measurement of radio disturbance characteristics of industrial, scientific and medical (ISM) radio-frequency equipment EMC product standard including special test methods for electric drive units 4 Product Information, 05/2010

5 Foreword 89/336/EWG 73/23/EWG Catalog DA65.10 COUNCIL DIRECTIVE of 3 May 1989 on the approximation of the laws of the Member States relating to electromagnetic compatibility Council Directive of 19 February 1973 on the harmonization of the laws of Member States relating to electrical equipment designed for use within certain voltage limits SIMOVERT MASTERDRIVES Vector Control Catalogue 2003/2004 6SE7087-6QX60 Masterdrives Compendium Vector Control SE7087-6CX87-8CE0 Prysmian (Pirelli) catalog BU IS Installation Instructions for EMC Correct Installation of Drives Flexible Electric Cables SINAMICS Engineering Manual SINAMICS G130, G150, S120 Chassis, S120 Cabinet Modules, S150 IEEE Transactions on Industrial Applications (Vol. 42, No. 4 July/August 2006) Article by Annette Muetze and Andreas Binder The implementation of these recommendations is no substitute for a risk assessment of the crane which needs to be made by the crane builder. Product Information, 05/2010 5

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7 Table of contents Foreword Introduction High frequency disturbance Long motor cables Common-mode oscillation Bearing current Selection of load side components Maximum cable length, no output reactor Maximum cable length and output reactor Voltage-limiting dv/dt filters Sine filters Sizing of cable cross section Conductors Protective conductor Power cable selection Types of power cable Insulation material used for power cables Power cables recommended by Siemens Installation guidelines Wiring guidelines in accordance to EMC rules Wiring requirements as per IEC Wiring practices to be avoided Best practices for screened power cable termination Termination in drive unit Termination in intermediate junction box Termination in motor junction box Installation of control cables Installation of PROFIBUS cables Installation of encoder cables Busbar connections (including cable connection) A Appendix A.1 Contact Product Information, 05/2010 7

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9 Introduction 1 Variable speed drives have become an integral component of the electrical control system for cranes. The installation of variable speed drives on cranes with increasing rated load and crane size has become a technical challenge. The following recommendations are meant to help the crane builder in carrying out the electrical installation and cabling in a way that latest aspects of variable speed drives parasitic effects are covered. 1.1 High frequency disturbance Variable-speed drives have advantages and disadvantages. One of the disadvantages is the high switching frequency of the semiconductor (IGBT) which can cause disturbances to other components. SIMOVERT MASTERDRIVES frequency converters operate with a voltage-source DC link. In order to keep the power losses as low as possible the inverter switches the DC link voltage to the motor winding in the form of voltage blocks. A reasonably sinusoidal current flows into the motor. Figure 1-1 Block diagram of a PWM converter with voltage-source DC link Product Information, 05/2010 9

10 Introduction 1.2 Long motor cables The described mode of operation in conjunction with high-performance semiconductor switching elements has made it possible to develop compact frequency converters which now play a vital role in drive technology. However, due to the fast switching a pulse-type noise current flows to ground through parasitic capacitances CP at each switching edge. Parasitic capacitances exist between the motor cable and ground and also within the motor. Figure 1-2 Block diagram showing output voltage V and fault current Is The source of the earth current IS is the inverter, thus this earth current must also flow back to the inverter. Impedance ZN and ground impedance ZE act in the return flow path. Impedance ZN forms parasitic capacitances between the supply cable and ground which is connected in parallel with the impedance (between phase and ground) of the supply transformer. The noise current itself and the voltage drops across ZN and ZE caused by the noise current can also affect other electrical units. Therefore, variable-speed drives generate high-frequency noise currents. EMC stands for "Electromagnetic Compatibility" and, in accordance with the EMC Law 2(7), it defines "the capability of a unit to operate satisfactorily in an electromagnetic environment, without itself causing electromagnetic disturbances which would be unacceptable for other electrical units in this environment". 1.2 Long motor cables Effect of crane mechanical configurations on the length of the electrical cables of a Ship-to- Shore (STS) type of crane: 10 Product Information, 05/2010

11 Introduction 1.2 Long motor cables Machinery on trolley (MOT) Positive: Shorter wire-ropes for hoist No wire-ropes for trolley Negative: Long electrical cables for hoist motors Long electrical cables for trolley motors Space constraints for hoist motors Self-propelled trolley (SPT) Positive No wire-ropes for trolley Negative Long electrical cables for trolley motors Product Information, 05/

12 Introduction 1.2 Long motor cables Rope-towed trolley (RTT) Positive: Shorter cables to hoist and trolley motors Negative: Long wire-ropes for hoist and trolley Typical Gantry configuration Negative: Accumulated long motor cables From all the examples above the gantry motion has the longest motor cable. A typical STS crane with the inverters mounted in the machinery house on the girder has accumulated gantry motor cable lengths reaching almost 1000 m. The industrial cranes have a large variety of designs in terms of the mechanical or electrical aspects. Siemens has so far identified the following 7 types of application industries for cranes: 12 Product Information, 05/2010

13 Introduction 1.2 Long motor cables 1. Cranes for metallurgical plants 2. Steel mill cranes 3. Installation and workshop cranes 4. Warehouse cranes 5. Shipyard cranes 6. Power house cranes 7. Other process cranes Figure 1-3 Some examples of industrial cranes However, most of the industrial cranes mentioned above can be classified as STS cranes. With this classification it can be further analyzed that two types of power cable routing methods are used: Festoon types E-Chain types E-chain types (although often not preferred by terminal operators for Harbour cranes) are usually used in long travel applications via integrated gliding mounts or shoes that are made from low wear polymers and plastics. Product Information, 05/

14 Introduction 1.3 Common-mode oscillation 1.3 Common-mode oscillation On large cranes with long motor feeder cables (e. g. SPT and MOT configurations) in combination with pulsed line-side converters, a common-mode oscillation may occur that could lead to excessive phase-to-ground voltage stress on the motors. Figure 1-4 Principal circuit for common-mode oscillation Engineering of the drive system has to consider carefully the entire drive train, comprising the medium voltage transformer the drive system with line-side converters and inverters on the common DC bus the motor with the insulation class the cabling between the different components 14 Product Information, 05/2010

15 Introduction 1.4 Bearing current 1.4 Bearing current Asymmetrical characteristics of the motor feeder cable in conjunction with the PWM switching pattern of the inverter leads to building up voltage between the rotor and the stator of the motor. If this voltage exceeds a certain threshold value the grease film lubricating the bearing will collapse and bring about a metal-metal contact. This leads to premature bearing failures. Figure 1-5 Types of bearing current in a typical crane system The figure above shows the fundamental bearing currents which can lead to premature bearing failures and also possible encoder failures (depending on the insulation of the encoder from the bearing). In the following you find a brief description of the various bearing currents shown above: Circular current High frequency leakage current flows between winding and housing and thus to ground which induces a high frequency shaft voltage (VShaft). Current flows from shaft to housing in one bearing and from housing back to shaft in the other bearing. Electrostatic Discharge Machining (EDM) current Phase-to-ground voltage (or referred to as "common mode voltage") charges the bearing capacitance. When the lubricating film on the bearing breaks down due to a high VBearing values the bearing capacitance and capacitance between winding and rotor discharges causing a high current pulse referred to as EDM. Rotor shaft current When the housing of the motor is badly grounded for the purpose of high frequency currents, this causes the leakage current (due to capacitance between winding and housing) to encounter a high resistance between housing and grounded systems across. If the gearbox / driven machine of the motor is grounded more effectively then the leakage current flows in this path and can further cause damages on the gearbox or driven machine bearings apart from the motor bearings. Product Information, 05/

16 Introduction 1.4 Bearing current As a conclusion, all motor feeder cables have to be screened and of symmetric design. Proper/effective grounding for the motor is to be ensured for the purpose of high frequency currents to avoid premature bearing damages. Bearing damage may be viewed as insignificant cost to other potential failures but it is nevertheless time consuming (especially for Hoist motors) contributes to crane down time leading to huge losses at the expense of terminal operators. 16 Product Information, 05/2010

17 Selection of load side components 2 The objective of the following chapters is to give a clear instruction on How to select the correct load-side components How to select suitable cable and type. How to implement correct wiring practices. Dimensioning of cable cross section Installation of power cables Installation of control cables The purpose of output reactors is to limit capacitive recharging currents into the capacitance of the motor feeder cable so as to protect the IGBTs in the drive. The selection of output reactors depends on the following parameters: Type of cables used (screened or unscreened; refer to table in the following chapter) Number of motors supplied from a converter When a converter/inverter supplies several motors (group drive) the capacitive charge / discharge currents of the motor cables are added. The total cable length is the sum of the cable lengths for the individual motors. 2.1 Maximum cable length, no output reactor The market of cables supplies a variety of applications and defines a myriad of criteria. However, cables can be categorized according to the following characteristics: Electrical (which will be looked at further in detail) Thermal Mechanical Chemical Electromagnetic capability Others (e. g. fire resistance etc.) This guideline will look into the selection of cable lengths in terms of cable capacitance and the remaining characteristics of the cables as mentioned above would be in favour of the crane builder/customer. The maximum cable lengths which can be connected to the standard SIMOVERT MASTERDRIVES unit without reactors are specified in the following table. Product Information, 05/

18 Selection of load side components 2.2 Maximum cable length and output reactor Table 2-1 Motor cable length without output reactor Output Rated voltage Non-shielded cables and PROTOFLEC EMV Shielded Cables to 4 kw 380 V to 600 V 50 m 35 m 5,5 kw 380 V to 600 V 70 m 50 m 7,5 kw 380 V to 600 V 100 m 67 m 11 kw 380 V to 600 V 110 m 75 m 15 kw 380 V to 600 V 125 m 85 m 18,5 kw 380 V to 600 V 135 m 90 m 22 kw 380 V to 600 V 150 m 100 m 30 kw to 200 kw 380 V to 690 V 150 m 100 m 250 kw to 630 kw 380 V to 480 V 200 m 135 m 710 kw to 1300 kw 380 V to 480 V Unlimited 900 kw to 1100 kw 380 V to 480 V 200 m 135 m 25 kw 0 to 2300 kw 500 V to 690 V 150 m 100 m 2.2 Maximum cable length and output reactor Whenever there are long power cables they should be dimensioned according to the following table. Table 2-2 Motor cable length when using output reactors Number of reactors in series Converter / Inverter Rating Rated Voltage Reactor 1) Reactor 1) Non-shielded cables Shielded cables 2) 0.55 kw to 1.1 kw 380 V to 480 V 100 m 3) 3) 60 m 3) 3) 1.5 kw to 4 kw 380 V to 600 V 90 m 3) 3) 100 m 3) 3) 5.5 kw 380 V to 600 V 200 m 3) 3) 135 m 3) 3) 7.5 kw 380 V to 600 V 225 m 450 m 3) 150 m 300 m 3) 11 kw 380 V to 600 V 240 m 480 m 3) 160 m 320 m 3) 15 kw 380 V to 600 V 260 m 520 m 3) 175 m 350 m 3) 18.5 kw 380 V to 600 V 280 m 560 m 3) 190 m 375 m 3) 22 kw 380 V to 600 V 300 m 600 m 900 m 200 m 400 m 600 m 30 kw to 200 kw 380 V to 690 V 300 m 600 m 900 m 200 m 400 m 600 m 250 kw to 630 kw 380 V to 480 V 400 m 800 m 1200 m 270 m 530 m 800 m 1100 kw 380 V to 480 V 400 m 800 m 1200 m 270 m 530 m 800 m 18 Product Information, 05/2010

19 Selection of load side components 2.2 Maximum cable length and output reactor Converter / Inverter Rating Number of reactors in series Rated Voltage Reactor 1) Reactor 1) Non-shielded cables Shielded cables 2) 250 kw to 2300 kw 4) 500 V to 690 V 300 m 600 m 900 m 200 m 400 m 600 m 900 kw to 1500 kw 5) 380 V to 690 V 300 m 450 m 600 m 200 m 300 m 450 m 1) In case of sizes M, N and Q, 2 inverters are connected in parallel and the number of reactors for the permissible cable lengths is therefore required for each inverter section. 2) The effective capacitance per unit length of the PROTOFLEX EMV cable corresponds to that of an unshielded cable. With the PROTOFLEX EMV cable, the same motor cable lengths are therefore possible as with an unshielded cable. 3) cannot be used. 4) Applies to sizes E, F, G, J, K, L, N and Q. 5) Applies to size M Voltage-limiting dv/dt filters Voltage limiting filters (output dv/dt filters for SIMOVERT MASTERDRIVES Vector Control) should be used for motors if the voltage strength of the insulation system is not known or is inadequate. The dv/dt filters limit the voltage rate-of-rise to values of < 500 V/ s and the typical voltage spikes for the rated supply voltage to the following values: < 1000 V at Vsupply 575 V < 1150 V at 660 V Vsupply 690 V Note The preceding rules are valid for a motor cable length of 150 m When reactors and filters are connected in series the cable lengths can be dimensioned according to the following table. Table 2-3 Motor cable length when using reactor and dv/dt filter Converter / Inverter rated current dv/dt filter dv/dt filter 1 reactor dv/dt filter 2 reactors 1) dv/dt filter dv/dt filter 1 reactor dv/dt filter 2 reactors 1) Non-shielded cables Shielded cables 5 A to 22 A 150 m 2) 2) 100 m 2) 2) 370 A 150 m 300 m 450 m 100 m 200 m 300 m 225 A 150 m 300 m 450 m 100 m 200 m 300 m 510 A to 1300 A 3) 150 m 375 m 2) 100 m 250 m 2) Product Information, 05/

20 Selection of load side components 2.2 Maximum cable length and output reactor Converter / Inverter rated current dv/dt filter dv/dt filter 1 reactor dv/dt filter 2 reactors 1) dv/dt filter dv/dt filter 1 reactor dv/dt filter 2 reactors 1) Non-shielded cables Shielded cables 297 A to 1230 A 4) 150 m 375 m 2) 100 m 250 2) 1400 A 5) 6) 6) 6) 6) 6) 6) 1) Voltage limiting is no longer effective for supply voltages of > 500 V. 2) Cannot be used. 3) Rated supply voltage 380 V to 480 V. 4) Rated supply voltage 500 V to 690 V. 5) Rated supply voltage 380 V to 690 V. 6) Not available at present. Note The total cable length is the sum of the cable lengths connected to the individual motors. From a motor current of 120 A, single-motor drives can also be supplied with parallel cables (up to the maximum permissible cable length) in case of standard units. Note The voltage limiting filters can be used up to a maximum frequency of 300 Hz. Note The dv/dt filters can only be used with a motor connected. 20 Product Information, 05/2010

21 Selection of load side components 2.2 Maximum cable length and output reactor Figure 2-1 Arrangement of output reactor and dv/dt filter Sine filters Sine filters ensure that motor voltage and motor current are almost sinusoidal. The harmonic distortion factor for a 50 Hz motor voltage with sine filter, for example, is approximately 5 %. The stressing levels of motors which are supplied via sine filters are lower than the values specified in DIN VDE When engineering the drive it should be ensured that the output voltage of converters and inverters with sine filters is approximately 85 % of the associated supply voltage at 380 V to 480 V and approximately 90 % at 500 V to 600 V. The sine filters for supply voltages of 380 V to 480 V are designed for a pulse frequency of 6 khz. The maximum output frequency is: Product Information, 05/

22 Selection of load side components 2.2 Maximum cable length and output reactor 400 Hz for compact units (sizes A to D) 200 Hz for chassis units (sizes E to G) Note Note the current derating for chassis units as a result of the 6 khz pulse frequency! The sine filters for supply voltages of 500 V to 600 V are designed for a pulse frequency of 3 khz. The maximum output frequency is: 200 Hz for compact units (sizes B to D) 100 Hz for chassis units (sizes E to G) Sine filters are suitable for supplying Ex (d) motors. They limit the voltage stressing in the motor terminal boxes from less than 1080 V up to a supply voltage of 500 V. For possible cable lengths see the following table. Table 2-4 Motor cable length and sine filter Output 380 V to 480 V 500 V to 600 V 380 V to 480 V 500 V to 600 V Non-shielded cables Shielded cables To 4 kw 250 m 350 m 170 m 250 m 5.5 kw 320 m 475 m 210 m 320 m 7.5 kw 400 m 550 m 270 m 400 m 11 kw 500 m 700 m 330 m 500 m 15 kw 600 m 900 m 400 m 600 m 18.5 kw to 132 kw A B 0.67 A A A = 600 m m/kw (P - 15 kw) B = 900 m + 10 m/kw (P - 15 kw) P: Rated motor output on the converter or inverter 22 Product Information, 05/2010

23 Sizing of cable cross section Conductors For information on the recommended cross-sectional area of the conductors for incoming and outgoing cables of every size: refer to the respective operating instructions of SIMOVERT MASTERDRIVES 3.2 Protective conductor The protective conductor has to be dimensioned considering the following aspects: In the event of an earth fault, it must be ensured that no excessively high touch voltages occur on the protective conductor as a result of voltage drops of the earth fault current (<50 VAC or 120 VDC, EN Section , IEC , IEC ). The earth fault current flowing in the protective conductor in the event of an earth fault must not overheat the protective conductor. Table 3-1 Recommended cross-sectional area of external protective conductors Cross-sectional area for phase conductors supplying the equipment S [mm 2 ] S 16 Minimum cross-sectional area of the external protective copper conductor SP [mm 2 ] 16 < S S > 35 S/2 The MASTERDRIVES converters, inverters, rectifier units (> 400 kw) and rectifier/regenerative units limit the current to an effective value in accordance to the rated current, thanks to their rapid control. Given these facts, we recommend that the cross-sectional area of the protective conductor is generally the same as the cross-sectional area of the outer conductor for earthing the control cubicle and the motor. S Product Information, 05/

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25 Power cable selection Types of power cable Table 4-1 Overview over power cable types Construction Shield EMC evaluation Symmetrical Cu braid (possibly with Cu fleece) Optimum Symmetrical 3-core Cu braid (single core) Good Unsymmetrical 4-core Cu braid (possibly with Cu fleece) Good Symmetrical Satisfactory Unsymmetrical 4-core Mediocre Unsymmetrical parallel cores or flat cable Cu braid Mediocre Unsymmetrical parallel cores or flat cable Poor Product Information, 05/

26 Power cable selection 4.2 Insulation material used for power cables 4.2 Insulation material used for power cables In view of minimizing the capacitance between the motor phase conductors and ground (see chapter High frequency disturbance (Page 9) ) it is advisable to choose cables with a possible specific capacitance as low as possible (pf/m). The cable capacitance is directly proportional to the dielectrical constant of the insulation material of the cable. Material such as cross-linked polyethylene (XLPE) have a dielectric constant of about 2, rubber in contrast may have a dielectric constant of Power cables recommended by Siemens In general, we highly recommend PROTOFLEX EMV 3 Plus for the following reasons: It can reduce the high frequency noise emission. It can reduce the bearing current effects. It has a minimal effective capacitance per unit length which is comparable to that of a standard unscreened cable (e. g. 3 x x 10 has a capacitance of 290 nf/km). The geometric arrangement of conductors and PE conductors is chosen such as to ensure identical coupling capacitances between phase to phase and phase to PE as shown in the figure below. Figure 4-1 Principal cross-sectional view of screened symmetric motor feeder cable However, it is important to check the cable specifications with the supplier! Different cable suppliers use different material for their cable sheaths, different quality with geometrical properties and so on. Therefore, compare the capacitance value / unit length of all these cables and select the one with the lowest value. For typical electrical and mechanical characteristics of power cables (PROTOFLEX EMV) see the two tables below: 26 Product Information, 05/2010

27 Power cable selection 4.3 Power cables recommended by Siemens Table 4-2 Electrical specification PROTOFLEX EMV Nominal voltage in three-phase AC operation U0 / U 0.6 / 1 kv Test AC voltage 4 kveff Maximum permissible peak AC voltage U 1.7 kv FC connection on 3 Level frequency converter with a nominal voltage Coupling resistance U 250 /km at 30 MHz Max. 690 V Current carrying capacity The definitions in DIN VDE 0298 part 4 apply. Table 4-3 Mechanical specification PROTOFLEX EMV Conductor according DIN VDE 0295 Copper, plain, finely stranded, class 5 Protective conductor according DIN VDE 0295 Copper, plain, finely stranded, class 5 For cross-sections > 16 mm 2 the protective conductor is divided in three cores Insulation according DIN VDE 0207 part 2 Core identification according DIN VDE 0293 Screen 1. Layer 2. Layer Thermoplastic compound on the basis of polyethylene (PE); compound 2YI1 Green / yellow, black, blue, brown Multilayer screen Al-coated plastic tape braid of tinned copper wires Sheath according DIN VDE 0207 part 5 Marking PVC compound YM2 colour of sheath: orange, transparent Cables with rated cross-section up to 10 mm 2 [Year of manufacture] PROTOFLEX EMV-FC 2YSLCY-J [number of cores] X [cross-section] 600/1000 V Cables with rated cross-section of 16 mm 2 [Year of manufacture] PROTOFLEX EMV-CY 2YSLCY-J [number of cores] X [cross-section] 600/1000 V [Year of manufacture] PROTOFLEX EMV-FC 2YSLCY-J [number of cores] X [cross-section] 600/1000 V [Year of manufacture] PROTOFLEX EMV-CY 3PLUS 2YSLCY-J [number of cores] X [cross-section] 600/1000 V Product Information, 05/

28 Power cable selection 4.4 Installation guidelines 4.4 Installation guidelines Typical wiring to the drive for the recommended power cable type Figure 4-2 Earthing and screening for motor connection Using non-shielded motor cables, the noise current flows in an undefined fashion back to the frequency converter, e. g. via the crane s steel structure, cable ducts, cabinet frames. These current paths have a very low resistance for currents with a frequency of 50 or 60 Hz. However, the noise current induces a high-frequency component which can result in problematical voltage drops. A shielded motor cable is necessary to enable the noise current to flow back to the frequency converter in a defined fashion. The shield must be connected to the housing of the frequency converter and to the motor housing through a large surface area. The shield now forms the easiest path for the noise current to take when returning to the frequency converter. Figure 4-3 Flow of the noise current with shielded motor cable A shielded motor cable with a shield connected at both sides causes the noise current to flow back to the frequency converter through the shield. The figure below illustrates the best wiring practices within as well as outside the panel enclosure following the 16 EMC rules in the next section which ensure minimum disturbances to other electrical components. 28 Product Information, 05/2010

29 Power cable selection 4.4 Installation guidelines Figure 4-4 Overview of best wiring practices adhering to EMC rules Wiring guidelines in accordance to EMC rules The design of drives must conform to EMC regulations. Rules 1 through 13 are generally applicable. Rules 14 through 16 are particularly important for limiting noise emission. Product Information, 05/

30 Power cable selection 4.4 Installation guidelines Rule 1 All of the metal cabinet parts must be connected using the largest possible surface areas (not paint on paint). Serrated washers should be used to ensure a good metal-metal contact. The cabinet door must be connected to the cabinet by grounding straps which must be kept as short as possible. Note Grounding measures for machines are essentially a protective measure. However, in case of drive systems grounding also has an influence on noise emission and noise immunity. A system can either be grounded in a star configuration or each component can be grounded separately. Preference should be given to the latter grounding system in the case of drive systems, i. e. all parts of the installation are connected via their surface or in a mesh pattern. Rules 2 and 3 Signal cables and power cables must be routed separately (to eliminate coupled-in noise). Minimum distance: 20 cm. If the minimum distance cannot be observed then partitions between power cables and signal cables as shown in the photo should be provided. The partitions must be grounded at several points along their length. Group : Very susceptible (e. g. analogue signals) Group : Susceptible (e. g. digital signals) Group : Noise source (e. g. control cables) Group : Strong noise source (e. g. output cables from drives) Figure 4-5 Power cables, grouped into partitions 30 Product Information, 05/2010

31 Power cable selection 4.4 Installation guidelines Note Contactors, relays, solenoid valves, surge arrestors, electromechanical operating hour counters, etc. in the cabinet must be provided with surge suppressor devices, for example, RC elements, diodes, varistors. These surge suppressor devices must be connected directly at the coil. Rule 4 Non-shielded cables associated with the same circuit (outgoing and incoming conductor) must be twisted or the surface between the outgoing and incoming conductors must be kept as small as possible in order to prevent unnecessary coupling effects. Rule 5 Eliminate any unnecessary cable lengths in order to keep coupling capacitances and inductances low. Rule 6 Connect the reserve cables / conductors to ground at both ends to achieve an additional shielding effect. Rule 7 In general, it is possible to reduce the noise being coupled-in by routing cables close to grounded cabinet panels. Therefore, wiring should be routed as close as possible to the cabinet housing and the mounting panels and not freely through the cabinet. The same applies for reserve cables / conductors. Product Information, 05/

32 Power cable selection 4.4 Installation guidelines Rule 8 Encoders must be connected through a shielded cable. The shield must be connected to the encoder housing and at the SIMOVERT MASTERDRIVES through a large surface area. The shield must not be interrupted, e. g. using intermediate terminals. For chassis units (sizes E), the shields can be additionally connected using cable ties (cable connectors) at the shield connecting locations. Figure 4-6 Connecting signal cable shields via 2 serrated bars in the cabinet Figure 4-7 Connecting signal cable shields via 2 screen rails in the cabinet 32 Product Information, 05/2010

33 Power cable selection 4.4 Installation guidelines Rule 9 The cable shields of digital signal cables must be connected to ground at both ends (transmitter and receiver) through the largest possible surface area. If the equipotential bonding is poor between the shield connections, an additional equipotential bonding conductor with at least 10 mm² must be connected in parallel to the shield, to reduce the shield current. Generally, the shields can be connected to ground (panel housing) in several places. The shields can also be connected to ground at several locations, even outside the cabinet. Figure 4-8 Examples of shield connections Foil-type shields are not suitable. Braided shields are at least 5 times as effective! Rule 10 The cable shields of analog signal cables can be connected to ground at both ends if the equipotential bonding is good. Good equipotential bonding is achieved if Rule 1 is observed. If low-frequency noise occurs on analog cables (e. g. speed/measured value fluctuations as a result of equalizing currents (hum)) the shields are only connected for analog signals at one end to the SIMOVERT MASTERDRIVES. The other end of the shield should be grounded through a capacitor (e. g. 10 nf/100 V type MKT). However, the shield is still connected at both ends to ground for high frequency as a result of the capacitor. Rule 11 If possible the signal cables should only enter the cabinet at one side. Rule 12 If SIMOVERT MASTERDRIVES are operated from an external 24 V power supply this power supply must not feed several consumers separately installed in various cabinets (hum can be coupled-in!). The best solution is to have a separate power supply for each SIMOVERT MASTERDRIVES. Rule 13 Prevent noise from being coupled-in through the supply. SIMOVERT MASTERDRIVES and PLC / control electronics should be connected-up to different supply networks. If there is only one common network, the PLC / control electronics have to be de-coupled from the supply using an isolating transformer. Product Information, 05/

34 Power cable selection 4.4 Installation guidelines Rule 14 In order to limit the noise emitted, all variable-speed motors have to be hooked up using shielded cables, with the shields being connected to the respective housings at both ends in a low-inductive manner (through the largest possible surface area). The motor feeder cables also have to be shielded inside the cabinet or at least shielded using grounded partitions. Suitable motor feeder cable e. g. Siemens PROTOFLEX EMV-CY with Cu shield. Cables with steel shields are unsuitable. Rule 15 The line supply cable has to be spatially separated from the motor feeder cables, e. g. by grounded partitions. Figure 4-9 View from the side of the incoming and outgoing cables Rule 16 The shield between the motor and SIMOVERT MASTERDRIVES must not be interrupted by the installation of components such as output reactors, sine filters, dv/dt filters, fuses, contactors. The components must be mounted on a mounting panel which simultaneously serves as the shield connection for the incoming and outgoing motor cables. Grounded partitions may be necessary to shield the components. 34 Product Information, 05/2010

35 Power cable selection 4.4 Installation guidelines Wiring requirements as per IEC Note All entries of "chapter" in the following refer to the respective chapters in IEC All connections must be securely fastened to prevent accidental loosening (chapter ). One protective conductor must be connected to one terminal connecting point unless the terminal is designed for two or more conductors (chapter ). Terminals on terminal blocks must be identified according to the markings in the drawing and clearly visible (chapter ). Figure 4-10 Terminals with proper marking For aluminium conductors consideration shall be given to the problem of electrolytic corrosion (chapter ). Figure 4-11 Cupal plates to interface transformer aluminium conductors to copper cable shoes Product Information, 05/

36 Power cable selection 4.4 Installation guidelines Cables outside enclosures are to be protected by suitable ducts, conduits or cable trunking systems; for exceptions refer to chapter Figure 4-12 Examples for routing of cable on cable ladders in sill beam Terminations of cable must be adequately supported to prevent mechanical stresses at the terminations of the conductors. Flexible conduit or flexible multi-conductor cable shall be used for connections involving small or infrequent movements. Excessive flexing and straining at the connection points has to be avoided (chapter ). Figure 4-13 Routing cable from main structure to boom across boom hinge 36 Product Information, 05/2010

37 Power cable selection 4.4 Installation guidelines All exposed conductive parts of the electrical equipment and structure must be connected to the protective bonding circuit to protect against electric shock. Figure 4-14 Protective bonding for junction boxes Continuity of protective bonding circuit must be observed. Removal of any equipment due to maintenance reason should not interrupt the protective bonding circuit (chapter 8.2.3). In case of IT supply, the structure will be used as part of the protective bonding circuit in conjunction with an earth fault supervision system (chapter 8.2.1). Product Information, 05/

38 Power cable selection 4.4 Installation guidelines Wiring practices to be avoided 1 Violation of IEC , clause requiring the PE conductor to be identified by colour green-yellow. 2 Signal cables (purple colour PROFIBUS bus communication cables) are mixed with power cables. Incoming power cables and outgoing motor feeder cables are not separated. 3 No EMC cable glands are used. Screens are connected to junction box PE via long pigtails. 4 Violation of IEC clause requiring that only one protective conductor shall be connected to one terminal connecting point. 38 Product Information, 05/2010

39 Power cable selection 4.4 Installation guidelines 5 Violation of IEC , clause The bolt fastening the cable shoe must be tightly fastened to the terminal connecting point. Serrated washers are to be used if the frame is painted. 6 Connection of cable screens via pigtails. 7 The screen connection of power cables and analog / digital signal cables on the same cable screen bar. 8 Violation of IEC clause Metal ducts of flexible or rigid construction and metallic cable sheaths shall not be used as protective conductors. Nevertheless, such metal ducts and the metal sheathing of all connecting cables (e. g. cable armouring, lead sheath) shall be connected to the protective bonding circuit Best practices for screened power cable termination The following sections show best practices for terminating screened power cable at the output of drive, intermediate junction box and motor junction box. Product Information, 05/

40 Power cable selection 4.4 Installation guidelines Termination in drive unit Figure 4-15 Terminating screened cable at drive unit end The figure above shows several interesting details: the colour of the cable is according to IEC the PE bar is indicated with the PE strips Green and Yellow strips. the cable screen is electrically connected to the cable retaining bar via a cut-off section of the cable exposing the screen braid clamped down by a galvanized steel U-clamp or metal cable tie. The U-clamp is a preferred solution. Figure 4-16 Connecting power cable shields on strain relief bar in cabinet The figure above shows the U-clamp types used to connect the screening braids of the screened (shielded) cables. These clamps have opposite pressure sleeves which provide a larger surface area for the screen connection, hence a better protection against electromagnetic influences. U-clamps made from non-magnetic materials such as stainless steel (e. g. PUK type K-AC LW) are a good choice for this type of installation. 40 Product Information, 05/2010

41 Power cable selection 4.4 Installation guidelines Termination in intermediate junction box Isolated mounting of screen bar to panel frame Figure 4-17 Cable screen connection The figure above shows an example of termination where the cable screen is connected to an isolated bar via metal cable tie. Connection for the cable screen can be done in one of the following ways: EMC cable glands used to connect the cable screen to the junction box housing which is grounded. Cable screen is connected via an insulated bar in each junction box which means there is no connection to ground at intermediate points. The insulated bars are connected via intermediate points Termination in motor junction box A suitable metallic gland with shield connection must be used at the motor to connect the shield. It should be ensured that there is a low impedance connection between the motor terminal box and the motor housing. If required an additional grounding conductor should be installed. CAUTION Do not use plastic motor terminal boxes and plastic cable glands! Product Information, 05/

42 Power cable selection 4.4 Installation guidelines Figure 4-18 Shield connection at the motor junction box The shield can be connected through a metallic gland made of either nickel plated brass material for indoor usage or stainless Steel AISI 316L for harsh outdoor environment with a strain relief bar. Degree of protection of up to IP 68 is also available and as shown in the figure below. EMI glands are available for example from the following suppliers: 42 Product Information, 05/2010

43 Power cable selection 4.4 Installation guidelines SKINDICHT SHVE, Messrs. Lapp, Stuttgart UNI IRIS Dicht or UNI EMV Dicht, Messrs. Pflitsch, Hückeswagen HUGRO Armaturen GmbH Only metal cable gland and metal terminal box used PE cable connected to PE terminal point Figure 4-19 Screened Power at the motor terminal box end Figure 4-20 Internal view of the terminal box with cable entry The examples above show how the usage of EMC cable glands completely avoids pigtails of the tinned copper braided shield connecting at the PE terminal connection. The external shield is properly cut away at the internal view of the terminal box and the shield is connected to the metal cable gland and to the housing of the motor terminal box. Product Information, 05/

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45 Installation of control cables Installation of PROFIBUS cables When you are laying the bus cable: Don't twist it! Don't stretch it! Don't squash it! In addition to this, you must take into account any influences on electromagnetic compatibility (EMC). The maximum cable length depends on the baud rate (transmission speed). The maximum cable length can be increased by using repeaters, but no more than three repeaters should be connected in series. The maximum cable lengths given in the following table can only be ensured if PROFIBUS bus cables are used (e. g. Siemens PROFIBUS cable with type number 6XV1830-0AH10). Table 5-1 Permissible baud rate as a function of cable length Baud rate Maximum cable length in a segment [m] Maximum distance between two stations [m] 9.6 to kbd kbd MBd to 12 MBd Figure 5-1 Termination resistor settings in PROFIBUS connectors Product Information, 05/

46 Installation of control cables 5.1 Installation of PROFIBUS cables Shielding of the bus cable / EMC measures In order to ensure interference-free operation of the PROFIBUS-DP especially in case of data transmission with RS485 the following measures are imperative: For the PROFIBUS cable, the shield in the bus connector should be connected to the drive s CBP card (CBP: Communication Board PROFIBUS). Shielding is also provided by the shield clamps (in the event of compact units) or by the shield clamps and cable ties (in the event of chassis-type units) on the converter housing. The following illustrations show you how to use the shield clamps. When removing the insulation from the various core ends please ensure that the solid copper core is not damaged. Figure 5-2 Connecting the signal cable shields for SIMOVERT MASTERDRIVES Ensure that the shield of each bus cable is connected to protective earth, both where it enters the cabinet and at the converter housing. Bus cables and power cables must not be laid parallel to each other. In case of crossing these cables should be laid in an angle of 90 to each other. The bus cables must be twisted and shielded and are to be laid separately from the power cables at a minimum distance of 20 cm. The braided shield and, if necessary, the underlying foil shield as well are to be connected on both sides through a large surface area so that they are highly conductive, i. e. the shield of the bus cable between two converters is to be connected to the converter housing at both ends of the cable. The same applies for the shielding of the bus cable between the PROFIBUS-DP master and the converters. 46 Product Information, 05/2010

47 Installation of control cables 5.2 Installation of encoder cables Figure 5-3 Installation with separate cable ducts 5.2 Installation of encoder cables Siemens crane duty motors (see catalog HE1 N 2007) generally are equipped with incremental pulse encoders sourced from Hübner, Berlin. Self-ventilated motors normally features hollow-shaft encoders type HOG. Non-ventilated motors are equipped with flange-mounted encoders type POG. Product Information, 05/

48 Installation of control cables 5.2 Installation of encoder cables Figure 5-4 Combination of HOG 10DN with FSL centrifugal overspeed switch Figure 5-5 HOG 10DN (left) and POG 10DN (right) It is recommended to install a pre-fabricated encoder cable. For example, Hübner sensor cable HEK 8 is a proven industrial product designed to match high demands. It is halogenfree and its rugged outer construction allows it to be pulled and dragged in free conditions. It is certified to UL The cable can be supplied in any length and pre-fitted with various mating connectors. Figure 5-6 HEK 8 cable at motor side (left) and at drive side (right) 48 Product Information, 05/2010

49 Installation of control cables 5.2 Installation of encoder cables Installation of encoder cables at motor side Housing Cover with o-ring Hollow shaft with spanner flat Support plat for torque arm Clamping element (only version with cylinder shaft) Earthing shaft, length approx. 230 mm Terminal box cover Cable fitting M20 x 1.5 for cable 5-13 mm Connection board SUB D connectors (male) on the encoder housing Figure 5-7 Encoder cable termination, plug type Product Information, 05/

50 Installation of control cables 5.2 Installation of encoder cables Figure 5-8 Encoder cable termination, terminal type Figure 5-9 Encoder cable terminal 50 Product Information, 05/2010

51 Installation of control cables 5.2 Installation of encoder cables Installation of encoder cables at drive side The encoder cable will be installed in the same manner as the PROFIBUS cable with all the precautions mentioned. After the shield is properly connected as according to chapter Installation of PROFIBUS cables (Page 45), the cables can be connected to the detachable terminal strips of either the SIMOVERT MASTERDRIVES CUVC or the SBP option board of the drives. Figure 5-10 Encoder cable signals Product Information, 05/

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53 Busbar connections (including cable connection) 6 To guarantee a proper connection to a busbar you have to use a bolt with conical washer and spring washer. The torque moment is depending on the thread size. Table 6-1 Connections by busbars or cables at connection busbars Termination type Bolting Conical spring washer DIN 6796 With spring washer - Screw: degree of firmness 8.8 (acc. ISO 898) nut: degree of firmness 8.8 (acc. ISO 898) Thread size Bolting with conical spring washer Torque [Nm] Bolting with spring water + washer DIN 125 Torque [Nm] Fixing Fixing Checking M M M Free of maintenance Maintenance necessary Torque check value = 70 % of fixing torque Product Information, 05/