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AC Drives - VTAC Drives from Rockwell Automation

1. Reliance Electric Inverter Rated Type A Type B 1488V Motor Motor HP kHz Shid Unshld Shid Unshld Shla Unshld Shld Shid Unshld 39 1 12 2 40 22 9 75 129 5 425 182 9 600 129 6 425 182 9 600 4 12 2 40 22 9 75 121 9 400 158 5 520 121 9 400 182 9 600 6 12 2 40 22 9 75 129 5 425 158 5 520 129 6 425 182 9 600 8 12 2 40 22 9 75 121 9 400 115 8 380 121 9 400 176 8 580 10 12 2 40 22 9 75 121 9 400 115 8 380 121 9 400 167 6 550 5 2 12 2 40 24 4 80 137 2 450 182 9 600 137 2 450 182 9 600 4 12 2 40 24 4 80 121 9 400 182 9 600 121 9 400 182 9 600 6 12 2 40 24 4 80 121 9 400 170 7 560 121 9 400 182 9 600 8 12 2 40 24 4 80 91 4 300 121 9 400 91 4 300 182 9 600 10 12 2 40 24 4 80 91 4 300 109 7 360 91 4 300 176 8 580 75 2 12 2 40 18 3 60 121 9 400 182 9 600 121 9 400 182 9 600 4 12 2 40 18 3 60 121 9 400 182 9 600 121 9 400 182 9 600 6 12 2 40 18 3 60 121 9 400 158 5 520 121 9 400 182 9 600 8 12 2 40 18 3 60 121 9 400 121 9 400 121 9 400 170 7 560 10 12 2 40 18 3 60 91 4 300 97 5 320 91 4 300 152 4 500 10 lo 12 2 40 18 3 60 121 9 400 182 9 600 121 9 400 182 9 600 4 12 2 40 18 3 60 121 9 4
2. Motor Cable Length Restrictions Tables A 3 Table A A VTAC 9 Drives 480V No External Devices Feet Meters Reliance Electric Inverter Rated Type A Type B 1488V Motor Motor HP kHz Shid Shid Unshld Shid Shia Unshid Shid Shid Unshld Shid Shid Unshid 30 12 21 3 70 15 2 50 182 9 600 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4 21 3 70 15 2 50 121 9 400 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 6 21 3 70 15 2 50 61 0 200 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 8 21 3 70 15 2 50 48 8 160 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 10 21 3 70 15 2 50 48 8 160 24 4 80 182 9 600 103 6 340 182 9 600 182 9 600 40 12 21 3 70 15 2 50 182 9 600 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4 21 3 70 15 2 50 121
3. 182 9 600 Oo Cable for Discrete Drive I O Wire Cable Types 1 11 Figure 1 11 Motor Cable Length All examples represent motor cable length of 182 9 meters 600 feet 15 2 50 91 4 300 wa 167 6 550 152 4 500 En gt E BER Co 15 2 50 15 2 50 er Important For multi motor applications review the installation carefully Consult Rockwell Automation when considering a multi motor application with greater than two motors In general most installations will have no issues However high peak cable charging currents can cause drive over currents or ground faults Discrete I O such as Start and Stop commands can be wired to the drive using a variety of cabling Shielded cable is recommended as it can help reduce cross coupled noise from power cables Standard individual conductors that meet the general requirements for type temperature gauge and applicable codes are acceptable if they are routed away from higher voltage cables to minimize noise coupling However multi conductor cable may be less expensive to install Control wires should be separated from power wires by at least 0 3 meters 1 foot Table 1 B Recommended Control Wire for Digital I O Minimum Type Wire Type s Description Insulation Rating Unshielded Per US NEC or applicable national 300V 60 C or local code 140 F Shielded Multi conductor shielded cable 0 750 mm 18AWG s
4. A single safety ground point or ground bus bar should be c gt directly connected to the building steel for cabinet installations All circuits including the AC input ground conductor should be grounded independently and directly DD to this point bar Isolated Inputs If the drive s analog inputs are from isolated devices and the output signal is not referenced to the ground the drive s inputs do not need to be isolated An isolated input is recommended to reduce the possibility of induced noise if the transducer s signal is referenced to ground and the ground potentials are varied Refer to Noise Related Grounds on page 3 3 An external isolator can be installed if the drive does not provide input isolation 3 8 Grounding Notes Mounting Chapter 4 Practices This chapter discusses various installation practices Standard Installations There are many criteria in determining the appropriate enclosure Some of these include Environment EMC Compatibility Compliance Available Space Access Wiring Safety Guidelines Grounding to the Component Mounting Panel In the example below the drive chassis ground plane is extended to the mounting panel The panel is made of zinc plated steel to ensure a proper bond between chassis and panel Figure 4 1 Drive Chassis Ground Plane Extended to the Panel Drive ground plane chassis bonded to panel TODOTUDUDTOTY
5. 1 6 Wire Cable Types Type 3 Installation Type 3 installation requires 3 symmetrical ground conductors whose ampacity equals the phase conductor Refer to Table 1 A on page 1 5 for detailed information and specifications on this installation Figure 1 6 Type 3 Unshielded Multi Conductor Cable PVC Outer Multiple Ground Conductors The outer sheathing and other mechanical characteristics should be chosen to suit the installation environment Consideration should be given to surrounding air temperature chemical environment flexibility and other factors as necessary in all installation types Shielded Cable Shielded cable contains all of the general benefits of multi conductor cable with the added benefit of a copper braided shield that can contain much of the noise generated by a typical AC Drive Strong consideration for shielded cable should be given for installations with sensitive equipment such as weigh scales capacitive proximity switches and other devices that may be affected by electrical noise in the distribution system Applications with large numbers of drives in a similar location imposed EMC regulations or a high degree of communications networking are also good candidates for shielded cable Shielded cable may also help reduce shaft voltage and induced bearing currents for some applications In addition the increased size of shielded cable may help extend the distance that the motor can be located from th
6. ne Sp seq Sw Y TAC Y DRIVES by Rockwell Automation Wiring and Grounding Guidelines for Pulse Width Modulated PWM AC Drives Installation Instructions Important User Information Solid state equipment has operational characteristics differing from those of electromechanical equipment Safety Guidelines for the Application Installation and Maintenance of Solid State Controls Publication SGI 1 1 available from your local Rockwell Automation sales office or online at http www rockwellautomation com literature describes some important differences between solid state equipment and hard wired electromechanical devices Because of this difference and also because of the wide variety of uses for solid state equipment all persons responsible for applying this equipment must satisfy themselves that each intended application of this equipment is acceptable In no event will Rockwell Automation Inc be responsible or liable for indirect or consequential damages resulting from the use or application of this equipment The examples and diagrams in this manual are included solely for illustrative purposes Because of the many variables and requirements associated with any particular installation Rockwell Automation Inc cannot assume responsibility or liability for actual use based on the examples and diagrams No patent liability is assumed by Rockwell Automation Inc with respect to use of information circuits equi
7. Communications Wiring Power Distribution Terminals Ground Bus Common mode noise current returning on the output conduit shielding or armor can flow into the cabinet bond and most likely exit through the adjacent input conduit armor bond near the cabinet top well away from sensitive equipment such as the PLC Common mode current on the return ground wire from the motor will flow to the copper PE bus and back up the input PE ground wire also away from sensitive equipment Refer to Proper Cabinet Ground Drives amp Susceptible Equipment on page 4 12 Ifa cabinet PE ground wire is run it should be connected from the same side of the cabinet as the conduit armor connections This keeps the common mode noise shunted away from the PLC backplane 4 12 Practices Common Mode Current on Cabinet Backplane Subpanel Cabinet Backplane Subpanel Figure 4 10 Proper Cabinet Ground Drives amp Susceptible Equipment Output Conduit or Armor Bonded to Cabinet A A UV WPE UV WPE RS TPE We l ommon Mode
8. Example 3 An ac output controls an interposing relay but the circuit can be opened by dry contacts Relay contacts control a solenoid coil The contacts require RC networks or Varistors The relay coil requires a suppressor because it is an inductive device controlled by dry contacts The solenoid coil also requires a suppressor because it is an inductive device controlled by dry contacts digital contact output Li pilot light with built in step down transformer D Z N suppressor Example 4 A contact output controls a pilot light with a built in step down transformer The pilot light requires a suppressor because its transformer is an inductive device controlled by a dry contact digital contact output 115V ac 1CR suppressor 480V ac brake solenoid Example 5 A contact output controls a relay which controls a brake solenoid The contacts require RC networks or Varistors Both the relay and the brake solenoid require suppressors because they are both inductive devices controlled by dry contacts Enclosure Lighting Electromagnetic Interference 6 7 Fluorescent lamps are also sources of EMI If you must use fluorescent lamps inside an enclosure the following precautions may help guard against EMI problems from this source as shown in the figure below install a shielding grid over the lamp use shielded cable between
9. Voltage Directive 73 23 EEC Generally recommended are flexible cables with a recommended bend radius of 20 times the cable diameter for movable cable and 6 times the cable diameter for fixed installations The screen shield should be between 70 and 85 coverage Insulation for both conductors and the outer sheath is PVC The number and color of individual conductors may vary but the recommendation is for 3 phase conductors customer preferred color and one ground conductor Green Yellow lflex Classic 100SY or lflex Classic 110CY are examples Figure 1 10 European Style Multi Conductor Cable PVC Outer Filler Sheath MO Stranded Neutral 1 10 Wire Cable Types Input Power Cables Motor Cables In general the selection of cable for AC input power to a drive has no special requirements Some installations may suggest shielded cable to prevent coupling of noise onto the cable see Chapter 2 and in some cases shielded cable may be required to meet noise standards such as CE for Europe C Tick for Australia New Zealand and others This may be especially true if an input filter is required to meet a standard Each individual drive user manual will show the requirements for meeting these types of standards Additionally individual industries may have required standards due to environment or experience For AC variable frequency drive applications that must satisfy EMC standards for CE C Tick FCC or other Rockwell Au
10. Zar _ Impedance 2 5 0 05 0 2304 Ohms gt Note that the percent impedance has to be in per unit 5 becomes 0 05 for the formula 0 00224 0 22 Z 102 6 drive 0 22 is less than 0 5 Therefore this transformer is too big for the drive and a line reactor should be added VTAC 9 Frames B C D E Shaded rows VTAC 9 Frames 2 3 4 5 6 1 Maximum suggested KVA supply without consideration for additional inductance Power Distribution 2 7 Note Grouping multiple drives on one reactor is acceptable however the reactor percent impedance must be large enough when evaluated for each drive separately not evaluated for all loads connected at once These recommendations are merely advisory and may not address all situations Site specific conditions must be considered to assure a quality installation Table 2 A AC Line Impedance Recommendations for VTAC 9 Drives Frames B C D E 3 Line Max Supply Reactor Open Reactor Reactor Current Drive Catalog Volts kW hp KVA 2 Style 1321 Inductance mh Rating Amps 9VT201 007HTNNN 208 1 5 2 50 3R8 A 1 5 8 9VT201 011HTNNN 208 2 2 3 50 3R12 A 1 25 12 9VT201 017HTANN 208 4 0 5 200 3R18 A 0 8 18 9VT201 025HTANN 208 5 5 7 5 250 3R25 A 0 5 25 9VT201 032HTANN 208 7 5 10 300 3R35 A 0 4 35 9VT201 062HTANN 208 15 20 1000 3R55 A 0 25 55 9VT201 078HTANN
11. 21 3 70 15 2 50 121 9 400 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 6 21 3 70 15 2 50 61 0 200 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 8 21 3 70 15 2 50 48 8 160 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 10 21 3 70 15 2 50 48 8 160 24 4 80 182 9 600 103 6 340 182 9 600 182 9 600 100 2 21 3 70 15 2 50 182 9 600 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4 21 3 70 15 2 50 121 9 400 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 6 21 3 70 15 2 50 61 0 200 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 125 2 21 3 70 15 2 50 182 9 600 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4 NA NA NA NA NA NA NA NA 6 NA NA NA NA NA NA NA NA 150 2 21 3 70 15 2 50 182 9 600 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4 NA NA NA NA NA NA NA NA 200 2 21 3 70 15 2 50 182 9 600 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4 NA NA NA NA NA NA NA NA O You can extend cable lengths by installing reactors at the drive end or other reflected wave mitigation devices RWRs or Terminators at the motor end Consult factory for recommendations O Cable is Alcatel C1202 or equivalent Shielded cable with twisted conductors and no filler Cable is Belden 295xx series or equivalent OQ Cable length restrictions at these r
12. 480 75 100 1000 3R130 B 0 2 130 9VT401 156HNANA 480 90 125 1500 3R160 B 0 15 160 9VT401 180HNANA 480 110 150 1500 3R200 B 0 11 200 2 8 Power Distribution Multi Drive Protection os EE A I Multiple drives on acommon power line should each have their own line reactor Individual line reactors provide filtering between each drive to provide optimum surge protection for each drive However if it is necessary to group more than one drive on a single AC line reactor use the following process to verify that the AC line reactor provides a minimum amount of impedance 1 In general up to 5 drives can be grouped on one reactor 2 Add the input currents of the drives in the group 3 Multiply that sum by 125 4 Use publication 1321 2 0 to select a reactor with a maximum continuous current rating greater than the multiplied current 5 Verify that the impedance of the selected reactor is more than 0 5 0 25 for drives with internal inductors of the smallest drive in the group by using the formulas below If the impedance is too small select a reactor with a larger inductance and same amperage or regroup the drives into smaller groups and start over line line Z arive J3 I input rating Za LTD reactor L is the inductance of the reactor in henries and f is the AC line frequency Power Distribution 2 9 Example There are 5 drives each is rated 1 HP 480V 2
13. 7 amps These drives do not have internal inductors Total current 5 2 7 amps 13 5 amps 125 Total current 125 13 5 amps 16 9 amps From publication 1321 2 0 we selected the reactor 1321 3R12 C which has a maximum continuous current rating of 18 amps and an inductance of 4 2 mh 0 0042 henries 480 Z A2 line line 102 6 Ohms 3 La rating 3 2 7 Zi Hesete 2I1 f 0 0042 2 II 60 1 58 Ohms Z Fresco _ 158 _ 0 0154 1 54 A 102 6 drive 1 549 1s more than the 0 5 impedance recommended The 1321 3R12 C can be used for the 5 2 7 amp drives in this example 2 10 Power Distribution Surge Protection MOVs and Common Mode Capacitors high resistance ground distribution system disconnect the phase to ground MOV circuit and the common mode capacitors from ground N ATTENTION When installing a drive on an ungrounded or Note In some drives a single jumper connects both the phase to ground MOV and the common mode capacitors to ground MOV Circuitry Most drives are designed to operate on three phase supply systems with symmetrical line voltages To meet IEEE 587 these drives are equipped with MOVs that provide voltage surge protection as well as phase to phase and phase to ground protection The MOV circuit is designed for surge suppression transient line protection only not for continuous operation Figure 2 1 Typical MOV Configuration PHASE TO PHASE MOV RATING Includes Two
14. MCM AWG 690V Applications Tray rated 2000V 90 C 194 F Three tinned copper conductors with XLPE insulation 3 Type 1 Installation without Brake Conductors Filler bare copper grounds and PVC jacket Note If terminator network or output filter is used connector insulation must be XLPE not PVC Unshielded Cable Properly designed multi conductor cable can provide superior performance in wet applications significantly reduce voltage stress on wire insulation and reduce cross coupling between drives The use of cables without shielding is generally acceptable for installations where electrical noise created by the drive does not interfere with the operation of other devices such as communications cards photoelectric switches weigh scales and others Be certain the installation does not require shielded cable to meet specific EMC standards for CE C Tick or FCC Cable specifications depend on the installation Type Type 1 amp 2 Installation Type 1 or 2 installation requires 3 phase conductors and a fully rated individual ground conductor without or with brake leads Refer to Table 1 A on page 1 5 for detailed information and specifications on these installations Figure 1 5 Type 1 amp 2 Unshielded Multi Conductor Cable without and with Brake Leads Type 2 Installation with Brake Conductors PVC Outer Filler PVC Outer Sheath Sheath Brake Single Ground Conductors Single Ground Conductor Conductor
15. Mode Chokes 6 2 6 3 Common Mode Noise Armored Cable 6 2 Causes 6 1 Conduit 6 2 Containing 6 2 Motor Cable Length 6 3 Shielded Cable 6 2 Communications 1 12 DeviceNet 1 12 Concentricity Insulation 1 4 Conductor Termination 4 18 Conductors 1 3 Index Conduit 4 13 Cable Connectors 4 5 Common Mode Noise 6 2 Entry 4 4 Entry Plates 4 4 Connections Ground 4 6 Contacts 6 3 6 4 Control Terminal 4 18 Control Wire 1 11 Conventions P 2 D Delta Delta with Grounded Leg 2 2 Delta Wye with Grounded Wye 2 1 DeviceNet 1 12 Diode 6 5 Discrete Drive I O Cable 1 11 Distribution Delta Delta with Grounded Leg 2 2 Delta Wye with Grounded Wye 2 1 High Resistance Ground 2 3 TN S Five Wire System 2 4 Ungrounded Secondary 2 3 Documentation P 1 E Electromagnetic Interference EMI Causes 6 3 Mitigating 6 4 Preventing 6 4 EMC Installation 4 2 Encoder Cable 1 12 European Style Cable 1 9 F Filter RFI 3 2 G Gauge 1 3 Geometry 1 4 Glands 4 5 Grounded Delta Delta 2 2 Delta Wye 2 1 Grounding 3 1 Acceptable Practices 3 5 Building Steel 3 1 Connections 4 6 Effective Practices 3 6 Fully Grounded System 3 5 High Resistance System 3 4 Motors 3 2 Optimal Practices 3 6 PE 3 2 Practices 3 5 4 1 RFI Filter 3 2 Safety 3 1 TN S Five Wire 3 2 Ungrounded 3 4 Grounding Practices 3 6 Grounds Noise Related 3 3 1 O Cable Discrete Drive 1 11 Impedance 2 5 Multiple Drives 2 9 Reactor 2 5 Inductive Loads Nois
16. more conservative methods 1 For drives without built in inductors add line impedance whenever the transformer KVA is more than 10 times larger than the drive kVA or the percent source impedance relative to each drive is less than 0 5 2 For drives with built in inductors add line impedance whenever the transformer KVA is more than 20 times larger than the drive kVA or the percent source impedance relative to each drive is less than 0 25 To identify drives with built in inductors see the product specific tables The shaded rows identify products ratings without built in inductors Use the following equations to calculate the impedance of the drive and transformer Drive Impedance in ohms Z Er Wine line dri rive B i I input rating 2 6 Power Distribution io ur 0 2304 Transformer Impedance in ohms Z km Niine tine Impedance 3 I fmr rated or 2 Zitmr mil Impedance Impedance is the nameplate impedance of the transformer Typical values range from 0 03 3 to 0 06 6 Transformer Impedance in ohms Z Viie line Impedance xfmr nee I xfmr rated Impedance is the nameplate impedance of the transformer Typical values range from 0 03 3 to 0 06 6 Example The drive is rated 1 Hp 480V 2 7A input The supply transformer is rated 50 000 VA 50 kVA 5 impedance Vine line 4 8 0V Z rive T7 102 6 ohms V3 Ta rating V3 2 7 Versi 480
17. path back to the inverter The dv dt and di dt from the circulating ground currents can couple into the signal and logic circuits causing improper operation and possible circuit damage When conventional grounding techniques do not work you must use high frequency bonding techniques If installers do not use these techniques motor bearing currents increase and system circuit boards have the potential to fail prematurely Currents in the ground system 6 2 Electromagnetic Interference Containing Common Mode Noise With Cabling may cause problems with computer systems and distributed control systems Cable type has a great effect on the ability to contain common mode noise in a system that incorporates a drive Conduit The combination of a ground conductor and conduit contains most capacitive current and returns it to the drive without polluting the ground grid A conduit may still have unintended contact with grid ground structure due to straps support etc The AC resistance characteristics of earth are generally variable and unpredictable making it difficult to predict how noise current will divide between wire conduit or the ground grid Shielded or Armored Power Cable The predominant return path for common mode noise is the shield armor itself when using shielded or armored power cables Unlike conduit the shield armor is isolated from accidental contact with grounds by a PVC outer coating Making the majority of noise current
18. rockwellautomation com and Maintenance of Solid State Control literature IEEE Guide for the Installation of Electrical IEEE 518 Equipment to Minimize Electrical Noise Inputs to Controllers from External Sources Recommended Practice for Powering and IEEE STD 1100 Grounding Electronic Equipment IEEE Emerald Book Electromagnetic Interference and Compatibility N A RJ White publisher Volume 3 Don White Consultants Inc 1981 Grounding Bonding and Shielding for Electronic Equipment and Facilities Military Handbook 419 IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems IEEE Std 142 1991 National Electrical Code ANSI NFPA 70 Articles 250 725 5 725 15 725 52 and 800 52 Noise Reduction Techniques in Electronic N A Henry W Ott Systems Published by Wiley Interscience Grounding for the Control of EMI N A Hugh W Denny Published by Don White Consultants Cable Alternatives for PWM AC Drive IEEE Paper No Applications PCIC 99 23 EMI Emissions of Modern PWM AC Drives N A IEEE Industry Applications Magazine Nov Dec 1999 EMC for Product Designers N A Tim Williams Published by Newnes Application Guide for AC Adjustable Speed N A NEMA Drive Systems www nema org IEC 60364 5 52 Selection amp Erection of N A IEC Electrical Equipment Wiring systems www iec ch Don t Ignore the Cost of Power Line Disturbance 1321 2 0 www rockwellautomation com l
19. standards If the enclosure door has a viewing window it should be a laminated screen or a conductive optical substrate to block EMC Do not rely on the hinge for electrical contact between the door and the enclosure install a grounding wire For doors 2 m 78 in in height two or three braided grounding straps between the door and the cabinet should be used EMC gaskets are not normally required for industrial systems Layout Plan the cabinet layout so that drives are separated from sensitive equipment Choose conduit entry points that allow any common mode noise to remain away from PLCs and other equipment that may be susceptible to noise Refer to Moisture on page 4 18 for additional information Practices 4 3 Hardware You can mount the drive and or mounting panel with either bolts or welded studs Figure 4 2 Stud Mounting of Ground Bus or Chassis to Back Panel Mounting Bracket Welded Stud Back Panel or Ground Bus N PA Flat Washer Paint Free Area Nut NY lf mounting bracket is coated with a non conductive material anodized painted etc scrape the material off Star Washer around the mounting hole Flat Washer EN 4 4 Practices Mounting Bracket or Ground Bus Flat Washer Nut Conduit Entry Figure 4 3 Bolt Mounting of Ground Bus or Chassis to Back Panel Back Panel Star Washer Bolt Flat Washer Nut Star Washer Paint Free Area Star Washer If mounting bracket is coate
20. than 20k total DeviceNet Remote 1 0 Data Highway Example Spacing relationship between 480V ac incoming power leads and 24V dc logic leads e 480V ac leads are Level 2 24V dc leads are Level 6 e For separate steel conduits the conduits must be 3 inches 76 mm apart e Ina cable tray the two groups of leads must be 6 inches 152 mm apart 4 10 Practices Spacing Notes 1 Both outgoing and return current carrying conductors are pulled in the same conduit or laid adjacent in tray 2 The following cable levels can be grouped together e s FP o A Level 1 Equal to or above 601V B Levels 2 3 amp 4 may have respective circuits pulled in the same conduit or layered in the same tray C Levels 5 4 6 may have respective circuits pulled in the same conduit or layered in the same tray Note Bundle may not exceed conditions of NEC 310 D Levels 7 8 8 may have respective circuits pulled in the same conduit or layered in the same tray Note Encoder cables run in a bundle may experience some amount of EMI coupling The circuit application may dictate separate spacing E Levels 9 10 4 11 may have respective circuits pulled in the same conduit or layered in the same tray Note Communication cables run in a bundle may experience some amount of EMI coupling and corresponding communication faults The application may dictate separate spacing Level 7 through Level 11 wires must be shielded per r
21. to a wide swing of AC line voltage Check the individual specification for the drives you are installing Incoming voltage imbalances greater than 2 can cause large unequal currents in a drive An input line reactor may be necessary when line voltage imbalances are greater than 2 AC Line Impedance Power Distribution 25 To prevent excess current that may damage drives during events such as line disturbances or certain types of ground faults drives should have a minimum amount of impedance in front of them In many installations this impedance comes from the supply transformer and the supply cables In certain cases an additional transformer or reactor is recommended If any of the following conditions exist serious consideration should be given to adding impedance line reactor or transformer in front of the drive A Installation site has switched power factor correction capacitors B Installation site has lightning strikes or voltage spikes in excess of 6000V Peak C Installation site has power interruptions or voltage dips in excess of 200VAC D The transformer is too large in comparison to the drive See impedance recommendation tables Table 2 A on page 7 and Table 2 B on page 7 that are specific to each drive Using these tables will allow the largest transformer size for each product and rating based on specific differences in construction and is the preferred method to follow Otherwise use one of the two following
22. u L i l Current on Armor i E or Conduit l Tht rhe ke il i I Incoming Power N il E Jii TT Comdluit Armor l l Io ma safaf d a 8 Eur E u In l Jun se A i j er i l l I co l l O o a 0000 O A EEE Within Conduit Do not route more than 3 sets of motor leads 3 drives in the same conduit Maintain fill rates per applicable electrical codes Do not run power or motor cables and control or communications cables in the same conduit If possible avoid running incoming power leads and motor leads in the same conduit for long runs Loops Antennas and Noise When routing signal or communications wires avoid routes that produce loops Wires that form a loop can form an efficient antenna Antennas work well in both receive and transmit modes these loops can be responsible for noise received into the system and noise radiated from the system Run feed and return wires together rather than allow a loop to form Twisting the pair Conduit Practices 4 13 together further reduces the antenna effects Refer to Avoiding Loops in Wiring on page 4 13 Figure 4 11 Avoiding Loops in Wiring oo 6 oe Not Recommended Good Solution Better Solution Magnetic steel conduit is preferred This type of conduit provides the best magnetic shielding Ho
23. used pull and twist the exposed shield after separation from the conductors Solder a flying lead to the braid to extend its length Ground Connections Ground conductors should be connected with care to assure safe and adequate connections For individual ground connections star washers and ring lugs should be used to make connections to mounting plates or other flat surfaces that do not provide proper compression lugs If a ground bus system is used in a cabinet follow the bus bar mounting diagrams Practices 4 7 Figure 4 6 Connections to Ground Bus Ground Bus Component i un ead Tapped Hole Grounding Conductors N Ground Lug Bolt 7 Component Grounding Star Washer Conductor Figure 4 7 Ground Connections to Enclosure Wall Welded Stud Ground Lug Paint Free Bolt Star Washer Area 1 ee Ss 7 3 AS ay P NO Y p Ground L gt 4 round Lug Star Washer Star Washer Nut Component Nut Component Ground Conductor Star Washer Ground Conductor 4 8 Practices Do not lay one ground lug directly on top of the other This type of connection can become loose due to compression of the metal lugs Sandwich the first lug between a star washer and a nut with another star washer following After tightening the nut sandwich the second lug between the first nut and a second nut with a captive star washer Figure 4 8 Multiple Connectio
24. withstand the voltage power and frequency of switching for your application These methods are not totally effective because they do not entirely eliminate arcing at the contacts DC Load A Load AC Load O The following table contains examples which illustrate methods for mitigating transient interference Examples of Transient Interference Mitigation digital contact output Example 1 A contact output controls a dc control V de relay 1CR The relay coil requires a suppressor blocking diode because it is an D inductive device controlled by a dry contact 6 6 Electromagnetic Interference Examples of Transient Interference Mitigation digital ac output Li 1MS solid state switch 1MS LI e I 1MS L2 h suppressor Im 1MS suppressor suppressor II H Example 2 An ac output controls a motor starter contacts on the starter control a motor The contacts require RC networks or Varistors The motor requires suppressors because it is an inductive device An inductive device controlled by a solid state switching device like the starter coil in this example typically does not require a suppressor digital ac output solid state switch L2 1CR
25. 00 182 9 600 121 9 400 182 9 600 6 NA 12 2 40 NA 18 3 60 121 9 400 170 7 560 NA 121 9 400 182 9 600 8 12 2 40 18 3 60 121 9 400 134 1 440 121 9 400 170 7 560 10 12 2 40 18 3 60 91 4 300 115 8 380 91 4 300 158 5 520 15 12 15 2 50 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4 15 2 50 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 6 15 2 50 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 8 15 2 50 24 4 80 182 9 600 152 4 500 182 9 600 182 9 600 10 15 2 50 24 4 80 182 9 600 121 9 400 182 9 600 146 3 480 20 2 15 2 50 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4 15 2 50 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 6 15 2 50 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 8 15 2 50 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 10 15 2 50 24 4 80 182 9 600 103 6 340 182 9 600 182 9 600 2 2 15 2 50 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4 15 2 50 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 6 15 2 50 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 8 15 2 50 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 10 15 2 50 24 4 80 182 9 600 103 6 340 182 9 600 182 9 600
26. 208 18 5 25 1000 3R80 A 0 2 80 9VT401 005HTNNN 480 2 2 3 75 3R8 C 5 8 9VT401 008HTNNN 480 3 7 5 100 3R8 B 3 8 9VT401 011HTANN 480 5 5 7 5 250 3R12 B 2 5 12 9VT401 014HTANN 480 7 5 10 250 3R18 B 1 5 18 9VT401 022HTANN 480 11 15 300 3R25 B 1 2 25 9VT401 027HTANN 480 15 20 400 3R35 B 0 8 35 9VT401 034HTANN 480 18 5 25 750 3R35 B 0 8 35 9VT401 040HTANN 480 22 30 1000 3R45 B 0 7 45 9VT401 052HTANN 480 30 40 1000 3R55 B 0 5 55 9VT401 065HTANN 480 37 50 1000 3R80 B 0 4 80 identify drive ratings without built in inductors Maximum suggested KVA supply without consideration for additional inductance Table 2 B AC Line Impedance Recommendations for VTAC 9 Drives Frames 2 3 4 5 6 3 Line Max Supply Reactor Open Reactor Reactor Current Drive Catalog Volts kW hp kva Style 1321 Inductance mh Rating Amps 9VT201 092HNANA 208 22 30 1000 3R100 A 0 15 100 9VT201 120HNANA 208 30 40 1000 3R130 A 0 1 130 9VT201 177HNANA 208 45 60 1000 3R160 A 0 075 160 9VT201 221HNANA 208 55 75 1000 3R200 A 0 055 200 9VT201 260HNANA 208 75 100 1000 3R320 A 0 04 320 9VT401 034HTANA 480 18 5 25 1000 3R35 B 0 8 35 9VT401 040HTANA 480 22 30 1000 3R45 B 0 7 45 9VT401 052HTANA 480 30 40 1000 3R55 B 0 5 55 9VT401 065HTANA 480 37 50 1000 3R80 B 0 4 80 9VT401 077HNANA 480 45 60 1000 3R80 B 0 4 80 9VT401 096HNANA 480 55 75 1000 3R100 B 0 3 100 9VT401 125HNANA
27. 9 400 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 6 21 3 70 15 2 50 61 0 200 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 8 21 3 70 15 2 50 48 8 160 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 10 21 3 70 15 2 50 48 8 160 24 4 80 182 9 600 103 6 340 182 9 600 182 9 600 50 12 21 3 70 15 2 50 182 9 600 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4 21 3 70 15 2 50 121 9 400 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 6 21 3 70 15 2 50 61 0 200 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 8 21 3 70 15 2 50 48 8 160 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 10 21 3 70 15 2 50 48 8 160 24 4 80 182 9 600 103 6 340 182 9 600 182 9 600 60 2 21 3 70 15 2 50 182 9 600 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4 21 3 70 15 2 50 121 9 400 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 6 NA 121 3 70 15 2 50 NA 61 0 200 24 4 80 NA 182 9 600 182 9 600 NA 182 9 600 182 9 600 8 21 3 70 15 2 50 48 8 160 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 10 21 3 70 15 2 50 48 8 160 24 4 80 182 9 600 103 6 340 182 9 600 182 9 600 75 2 21 3 70 15 2 50 182 9 600 24 4 80 182 9 600 182 9 600 182 9 600 182 9 600 4
28. Armored A fixed geometry cable that has a protective sheath of continuous metal Capacitive Coupling Current or voltage that is induced on one circuit by another because of their close physical proximity For drive installations it is generally seen in two areas 1 Coupling between motor leads of two drives such that the operating drive induces voltage onto the motor leads and thus the motor of a non operating drive 2 Coupling between the conductors or shields of motor leads that creates a requirement for more current than the motor itself would demand CIV Corona Inception Voltage The amplitude of voltage on a motor or other electrical winding that produces corona ionization of air to ozone CIV is increased by adding phase paper placing windings in the proper pattern and reducing or eliminating air bubbles voids in the varnish applied Common Mode Core A ferrite bead or core that can be used to pass control communications or motor leads through to attenuate high frequency noise Catalog Number Part Number 1321 Mxxx Common Mode Noise Electrical noise typically high frequency that is imposed on the ground grid carriers in an electrical system Conduit Conductive ferrous electrical metal tubing used to contain and protect individual wires Damp Wet locations per U S NEC or local code Glossary 2 Discrete Individual hard wired inputs or outputs typically used for control of the drive Start St
29. Phase to Phase MOV s Three Phase AC Input PHASE TO GROUND MOV RATING Includes One Phase to Phase MOV and One Phase to Ground MOV Ground With ungrounded distribution systems the phase to ground MOV connection can become a continuous current path to ground Exceeding the published phase to phase phase to ground voltage or energy ratings may cause physical damage to the MOV Suitable isolation is required for the drive when there is potential for abnormally high phase to ground voltages in excess of 125 of nominal line to line voltage or when the supply ground is tied to another system or equipment that could cause the ground potential to vary with operation An isolation transformer is strongly recommended when this condition exists Common Mode Capacitors Many drives also contain common mode capacitors that are referenced to ground In installations with ungrounded or high resistive grounded systems the common mode capacitors can capture high frequency common mode or ground fault currents This could cause over voltage conditions which could lead to damage or drive faults Grounding Safety Grounds Chapter 3 Grounding This chapter discusses various grounding schemes for safety and noise reduction An effectively grounded scheme or product is one that is intentionally connected to earth through a ground connection or connections of sufficiently low impedance and having sufficient current carrying capacity to prevent t
30. T DVI 000000000000000000 Note Where TE and PE terminals are provided ground each separately to the nearest point on the panel using flat braid In an industrial control cabinet the equivalent to the copper ground layer of a PCB is the mounting panel To make use of the panel as a ground plane it 4 2 Practices should be made of zinc plated mild steel If painted remove the paint at each mounting and grounding point Zinc plated steel is strongly recommended due to its inherent ability to bond with the drive chassis and resist corrosion The disadvantage with painted panels apart from the cost in labor to remove the paint is the difficulty in making quality control checks to verify if the paint has been properly removed and any future corrosion of the unprotected mild steel may compromise noise performance Plain stainless steel panels are also acceptable but are inferior to zinc plated mild steel due to their higher ohms per square resistance Though not always applicable a plated cabinet frame is also highly desirable since it makes a high frequency bond between panel and cabinet sections more reliable Doors For doors 2 m 78 in in height ground the door to the cabinet with two or three braided straps EMC seals are not normally required for industrial systems EMC Specific Installations A steel enclosure is recommended A steel enclosure can help guard against radiated noise to meet EMC
31. a cable with 3 ground conductors Figure 4 4 Terminating the Shield with a Connector Metal connector body Braid wires pulled back in a 360 makes direct contact with pattern around the ground cone of the the braid wires connector Drain wires pulled back in a 360 Metal locknut bonds the pattern around the ground cone of the connector to the panel connector Important This is mandatory for CE compliant installations to meet requirements for containing radiated electromagnetic emissions Shield termination via Pigtail Lead If a shield terminating connector is not available the ground conductors or shields must be terminated to the appropriate ground terminal If necessary use a compression fitting for ground conductor s and or shields together as they leave the cable fitting 4 6 Practices U T1 V T2 W T3 PE PE 928280808 Figure 4 5 Terminating the Shield with a Pigtail Lead Exposed shield TA mE E Flying lead soldered to braid Important This is an acceptable industry practice for most installations to minimize stray common mode currents Pigtail termination is the least effective method of noise containment It is not recommended if e the cable length is greater than 1 m 39 in or extends beyond the panel e in very noisy areas e the cables are for very noise sensitive signals for example registration or encoder cables e strain relief is required If a pigtail is
32. able set of another drive even when no power is applied to the second drive Figure 4 12 Recommended Cable Tray Practices Bundled and Anchored to Tray Recommended arrangements for multiple cable sets AT Pe AS AT Pe RXSXTP 0900 Carefully arrange the geometry of multiple cable sets Keep conductors within each group bundled Arrange the order of the conductors to minimize the current which induced between sets and to balance the currents This is critical on drives with power ratings of 200 hp 150 kW and higher Maintain separation between power and control cables When laying out cable tray for large drives make sure that cable tray or conduit containing signal wiring is separated from the conduit or trays containing power or motor wiring by 3 feet or more Electromagnetic fields from power or motor currents can induce currents in the signal cables Dividers also provide excellent separation Shield Termination Practices 4 15 Refer to Shield Splicing on page 3 7 to splice shielded cables The following methods are acceptable if the shield connection to the ground is not accomplished by the gland or connector Refer to the table associated with each type of clamp for advantages and disadvantages Termination via circular clamp Clamp the cable to the main panel closest to the shield terminal using the circular section clamping method The preferred method for grounding cable shields is clamping the circu
33. an acceptable method of grounding Under a short circuit secondary condition any of the output phases to ground will not exceed the normal line to line voltage This is within the rating of the MOV input protection devices on the drive The resistor is often used to detect ground current by monitoring the associated voltage drop Since high frequency ground current can flow through this resistor care should be taken to properly connect the drive motor leads using the recommended cables and methods In some cases multiple drives that may have one or more internal references to ground on one transformer can produce a cumulative ground current that can trigger the ground fault interrupt circuit Refer to Surge Protection MOVs and Common Mode Capacitors on page 2 10 2 4 Power Distribution AC Line Voltage TN S Five Wire System L1 L2 L3 PEN or N PE TN S five wire distribution systems are common throughout Europe with the exception of the United Kingdom and Germany Leg to leg voltage commonly at 400V powers three phase loads Leg to neutral voltage commonly at 230V powers single phase loads Neutral is a current conducting wire and connects through a circuit breaker The fifth wire is a separate ground wire There is a single connection between ground and neutral typically in the distribution system There should be no connections between ground and neutral within the system cabinets In general all VTAC drives are tolerant
34. andard cables used in the past may not represent the best choice for customers using variable speed drives Drive installations benefit from using cable that is significantly different than cable used to wire contactors and push buttons e Safety issues including electrical code requirements grounding needs and others Choosing incorrect cable can be costly and may adversely affect the performance of your installation 1 2 Wire Cable Types General PVC Insulation Thickness 15 mil Selecting Wire to Withstand Reflected Wave Voltage for New and Existing Wire Installations in Conduit or Cable Trays Material Use Copper wire only The wire clamp type terminals in VTAC drives are made for use with copper wire only If you use aluminum wire the connections may loosen Wire gauge requirements and recommendations are based on 75 degrees C Do not reduce wire gauge when using higher temperature wire Exterior Cover Whether shielded or unshielded the cable must be chosen to meet all of the application requirements Consideration must be given to insulation value and resistance to moisture contaminants corrosive agents and other invasive elements Consult the cable manufacturer and the chart below for proper selection Figure 1 1 Wire Selection Flowchart Conductor DRY Per Environment NEC Article 100 WET Per NEC Article 100 XLPE XHHW 2 Conductor Insulation for Insul
35. at has a PVC exterior jacket This PVC jacket prevents accidental contact with building steel and reduces the possibility that noise will enter the ground grid Shielded or MOTOR FRAME Armored Cable with PVC Jacket INPUT TRANSFORMER Connection to Drive Structure or 4 onnection to wa a Optional Cabinet Via Grounding O lt Panel Ground Bus Connector or Terminating Girder or Ground Rod 7 Saa e En A Shield at PE Terminal Ye Connection to OPTIONAL ENCLOSURE Frame Cabinet Ground Bus Ground or Directly to Drive PE Terminal BUILDING GROUND POTENTIAL Optimal Recommended Grounding Practices The fully grounded scheme provides the best containment of common mode noise It uses PVC jacketed shielded cable on both the input and the output to the drive This method also provides a contained noise path to the transformer to keep the ground grid as clean as possible Shielded or Shielded or MOTOR FRAME Armored Cable lt Armored Cable with PVC Jacket with PVC Jacket INPUT TRANSFORMER lt Connection to Ground Grid Girder or Ground Rod Connection to Drive Structure or Optional Cabinet Via Grounding Connector or Terminating A Shield at PE Terminal Connection to Drive Structure or Motor Optional Cabinet Via Grounding OPTIONAL ENCLOSURE Frame Connection to Ground Connector or Terminating Shield at PE Terminal Cabinet Gro
36. atings are partially attributed to cable charging current NR Not Recommended NA Not Available at time of printing A 4 Motor Cable Length Restrictions Tables Table A B VTAC 9 Drives 460V with Reactor Meters Feet Reliance Electric Inverter Rated Motor Shld e Type A Motor Type B Motor 1488 Volt motor O Cable is Alcatel C1202 or equivalent Shielded cable with twisted conductors and no filler O Cable is Belden 295xx series or equivalent NR Not Recommended NA Not Available at time of printing Table A C VTAC 9 Drives 460V with RWR or Eliminator Meters Feet Reliance Electric Inverter Rated Type A Motor Type B Motor 1488 V Motor Motor HP kHz Shid ShidO Unshld Shld ShidO Unshld Shld ShidO Unshid Shide Shld Unshld 3 2 NA NA 4 182 9 600 182 9 600 6 10 NA NA 5 2 NA NA 4 182 9 600 182 9 600 6 10 NA NA 75 2 NA NA 4 NM NA 61 0 200 NA NA 182 9 600 NA dd 6 10 NA NA 10 2 NA NA 4 61 0 200 182 9 600 6 10 15 2 10 NA NA 20 2 10 O Cable is Alcatel C1202 Or equivalent Shielded cable with twisted conductors and no filler Cable is Belden 295xx series or equivalent NR Not Recommended NA Not Available at time of printing Glossary Ambient Air Air around any equipment cabinet See surrounding air for more detail
37. ation ALPE lt 600V AC System No RWR or 20 mil or gt 1 Terminator Required 208 230V RW Term Ror inator 400 460V Reflected Wave Reducer No RWR or Terminator lt 50 ft OK for lt 600V AC System No RWR or Terminator required Multiple Drives in Single Conduit ER A or Terminator or Wire Tray Drives in Same Conduit or Wire RWR or Terminator 15 mil PVC 15 mil PVC Single Drive Not Not Single Conduit Recommended Recommended or Wire Tray USE XLPE USE XLPE or gt 20 mil or gt 20 mil See NEC Guidelines Article 310 Adjustment Factors for Maximum 1 The mimimum wire size for PVC cable with 20 mil or greater insulation is 10 gauge Conductor Derating and Maximum Wires in Conduit or Tray Wire Cable Types 1 3 Temperature Rating In general installations in surrounding air temperature of 50 C should use 90 C wire required for UL and installations in 40 C surrounding air temperature should use 75 C wire also required for UL Refer to the drive user manual for other restrictions The temperature rating of the wire affects the required gauge Be certain to meet all applicable national state and local codes Gauge The proper wire size is determined by a number of factors Each individual drive user manual lists a minimum and maximum wire gauge based on the amperage rating of the drive and t
38. d with a non conductive material anodized painted etc scrape the material off around the mounting hole If the drive chassis does not lay flat before the nuts bolts are tightened use additional washers as shims so that the chassis does not bend when you tighten the nuts Entry Plates In most cases the conduit entry plate will be a paint free conductive material The surface of the plate should be clean of oil or contaminants If the plate is painted use a connector that cuts through the paint and makes a high quality connection to the plate material Or Remove the paint around the holes to the bare metal one inch in from the edge of the plate Grind down the paint on the top and bottom surfaces Use a high quality joint compound when reassembling to avoid corrosion Practices 4 5 Cable Connectors Glands Choose cable connectors or glands that offer the best cable protection shield termination and ground contact Refer to Shield Termination on page 4 15 for more information Shield terminating connectors The cable connector selected must provide good 360 contact and low transfer impedance from the shield or armor of the cable to the conduit entry plate at both the motor and the drive or drive cabinet for electrical bonding SKINTOP MS SC MS SCL cable grounding connectors and NPT PG adapters from LAPPUSA are good examples of this type of shield terminating gland Use a connector with 3 ground bushings when using
39. dant heat resistant thermoplastic insulation is the type of insulation listed in the NEC code for the THHN wire designation This type of insulation is commonly referred to as PVC In addition to manufacturing inconsistencies the physical properties of the cable can change due to environment installation and operation which can also lead to premature insulation degradation The following is a summary of our findings Due to inconsistencies in manufacturing processes or wire pulling air voids can also occur in the THHN wire between the nylon jacket and PVC insulation Because the dielectric constant of air is much lower than the dielectric constant of the insulating material the transient reflected wave voltage might appear across these voids If the corona inception voltage 5 2 Reflected Wave Length Restrictions For Motor Protection CIV for the air void is reached ozone is produced Ozone attacks the PVC insulation leading to a breakdown in cable insulation Asymmetrical construction of the insulation has also been observed for some manufacturers of PVC wire A wire with a 15 mil specification was observed to have an insulation thickness of 10 mil at some points The smaller the insulation thickness the less voltage the wire can withstand THHN jacket material has a relatively brittle nylon that lends itself to damage i e nicks and cuts when pulled through conduit on long wire runs This issue is of even greater concern when the w
40. e drive without the addition of motor protective devices such as terminator networks Refer to Chapter 5 for information regarding reflected wave phenomena Consideration should be given to all of the general specifications dictated by the environment of the installation including temperature flexibility moisture characteristics and chemical resistance In addition a braided shield should be included and specified by the cable manufacturer as having coverage of at least 75 An additional foil shield can greatly improve noise containment Drain Wire Drain Wire for Brake Conductor Brake Conductors Wire Cable Types 1 7 Type 1 Installation A good example of acceptable shielded cable for Type 1 installation is Belden 295xx xx determines gauge or Anixter B209500 B209507 These cables have 4 XLPE insulated conductors with a 100 coverage foil and an 85 coverage copper braided shield with drain wire surrounded by a PVC jacket For detailed specifications and information on these installations refer to Table 1 A on page 1 5 Figure 1 7 Type 1 Installation Shielded Cable with Four Conductors Type 2 Installation A good example of acceptable shielded cable for Type 2 installation is Anixter OLF 7xxxxx This is essentially the same cable as Type 1 plus one 1 shielded pair of brake conductors For more information on this installation refe
41. e 6 3 6 4 Input Power Cables 1 10 Inputs Isolated 3 7 Installation EMC Specific 4 2 Layout 4 2 Practices 4 1 Insulation 1 1 1 2 1 4 1 9 1 10 1 12 4 13 4 18 5 1 L Layout Installation 4 2 Length Common Mode Noise 6 3 Motor Cable 1 11 Restrictions 5 2 Length Restrictions A 1 Lighting Noise 6 7 Line Impedance AC Line Impedance 2 5 Multiple Drives 2 9 M Manual Conventions P 2 Manual Usage P 1 Material Cable 1 2 Mode Capacitors Common 2 11 Moisture 1 2 4 18 5 2 Motor 1329R L A 1 1488V A 1 Brake Solenoid Noise 6 3 6 4 Grounding 3 2 Type AA 1 Type BA 1 Motor Brake Solenoid Noise 6 3 6 4 Motor Cable Length 1 11 Motor Cable Length Restrictions A 1 Motor Starters Noise 6 3 6 4 Motors Noise 6 3 6 4 Mounting 4 1 MOV Surge Protection 2 11 Multiple Drives Line Impedance 2 9 Reactor 2 9 N Noise Brake 6 3 6 4 Common Mode 6 1 Contacts 6 3 6 4 Enclosure Lighting 6 7 Inductive Loads 6 4 Lighting 6 7 Mitigating 6 4 Motor Brake 6 3 6 4 Motor Starters 6 3 6 4 Motors 6 3 6 4 Preventing 6 4 Related Grounds 3 3 Relays 6 3 6 4 Solenoids 6 3 6 4 Switch Contacts 6 3 6 4 Transient Interference 6 3 6 4 p Power Wire 1 10 1 11 1 12 3 7 4 14 4 18 6 2 Power Cables Input 1 10 Power Distribution 2 1 Delta Delta with Grounded Leg 2 2 Delta Wye with Grounded Wye 2 1 High Resistance Ground 2 3 TN S Five Wire System 2 4 Ungrounded Secondary 2 3 Power Terminals 4 18 Practices Ground
42. ecommendations In cable trays steel separators are advisable between the class groupings If conduit is used it must be continuous and composed of magnetic steel Spacing of Communication cables Levels 2 through 6 is the following Conduit Spacing Through Air Spacing 115V 1 inch 115V 2 inches 230V 1 5 inches 230V 4 inches 460 575V 3 inches 460 575V 8 inches 575 volts proportional to 6 inches 575V proportional to 12 inches Per 1000V Per 1000V 7 If more than one brake module is required the first module must be mounted within 3 0 m 10 ft of the drive Each remaining brake module can be a maximum distance of 1 5 m 5 ft from the previous module Resistors must be located within 30 m 100 ft of the chopper module Within A Cabinet When multiple equipment is mounted in a common enclosure group the input and output conduit armor to one side of the cabinet as shown in Separating Susceptible Circuits on page 4 11 Separating any Programmable Logic Controller PLC or other susceptible equipment cabling to the opposite side will minimize many effects of drive induced noise currents Practices 4 11 Figure 4 9 Separating Susceptible Circuits PWM Drives Programmable Logic Controller and Other Control Circuits Drive Power Wiring Sensitive Equipment Drive Control and
43. elded Cable 1 5 V Varistors 2 11 6 4 W Wire Index 4 Control 1 11 Insulation 1 1 1 2 1 4 1 9 1 10 1 12 4 13 4 18 5 1 Power 1 10 1 11 1 12 3 7 4 14 4 18 6 2 Signal 1 12 Wire Routing Antennas 4 12 Loops 4 12 Noise 4 12 Within a Cabinet 4 10 Within Conduit 4 12 Wire Cable Types 1 1 Armored Cable 1 8 Conductors 1 3 European Style Cable 1 9 Exterior Cover 1 2 Gauge 1 3 Geometry 1 4 Insulation Thickness 1 4 Material 1 2 Reflected Wave Effects 5 1 Shielded Cable 1 6 Temperature Rating 1 3 Unshielded Cable 1 5 Wiring Category Definitions 4 9 Routing 4 9 Spacing 4 9 Spacing Notes 4 10 Z Zero Cross Switching 6 3 6 4 www rockwellautomation com vtac VTAC Headquarters Rockwell Automation 6400 West Enterprise Drive Mequon Wisconsin 53092 USA Tel 910 262 512 8200 Publication VTAC IN002A EN P July 2006 Copyright 2006 Rockwell Automation Inc All rights reserved Printed in USA
44. flow in the controlled path and very little high frequency noise flows into the ground grid Noise current returning on the shield or safety ground wire is routed to the drive PE terminal down to the cabinet PE ground bus and then directly to the grounded neutral of the drive source transformer Take care when bonding the armor or shield to the drive PE A low impedance cable or strap 1s recommended when making this connection as opposed to the smaller gauge ground wire either supplied as part of the motor cable or supplied separately Otherwise the higher frequencies associated with the common mode noise will find this cable impedance higher and look for a lower impedance path The cable s radiated emissions are minimal because the armor completely covers the noisy power wires Also the armor prevents EMI coupling to other signal cables that might be routed in the same cable tray Another effective method of reducing common mode noise is to attenuate it before it can reach the ground grid Installing a common mode ferrite core on the output cables can reduce the amplitude of the noise to a level that makes it relatively harmless to sensitive equipment or circuits Common mode cores are most effective when multiple drives are located in a relatively small area For more information see the 32 M Common Mode Chokes Instructions publication 1321 5 0 How Electromechanical Switches Cause Transient Interference A We Power Elec
45. he buildup of voltages which may result in undue hazard to connected equipment or to persons as defined by the US National Electric Code NFPA70 Article 100B Grounding of a drive or drive system is done for 2 basic reasons safety defined above and noise containment or reduction While the safety ground scheme and the noise current return circuit may sometimes share the same path and components they should be considered different circuits with different requirements The object of safety grounding is to ensure that all metalwork is at the same ground or Earth potential at power frequencies Impedance between the drive and the building scheme ground must conform to the requirements of national and local industrial safety regulations or electrical codes These will vary based on country type of distribution system and other factors Periodically check the integrity of all ground connections General safety dictates that all metal parts are connected to earth with separate copper wire or wires of the appropriate gauge Most equipment has specific provisions to connect a safety ground or PE protective earth directly to it Building Steel If intentionally bonded at the service entrance the incoming supply neutral or ground will be bonded to the building ground Building steel is judged to be the best representation of ground or earth The structural steel of a building is generally bonded together to provide a consistent ground potentia
46. he physical limitations of the terminal blocks Local or national electrical codes also set the required minimum gauge based on motor full load current FLA Both of these requirements should be followed Number of Conductors While local or national electrical codes may determine the required number of conductors certain configurations are recommended Figure 1 2 on page 1 3 shows cable with a single ground conductor which is recommended for drives up to and including 200 hp 150 kW Figure 1 3 on page 1 4 shows cable with three ground conductors which is recommended for drives larger than 200 hp 150 kW The ground conductors should be spaced symmetrically around the power conductors The ground conductor s should be rated for full drive ampacity Figure 1 2 Cable with One Ground Conductor One Ground Conductor 1 4 Wire Cable Types Figure 1 3 Cable with Three Ground Conductors Three Ground Conductors Insulation Thickness and Concentricity Selected wire must have an insulation thickness of equal to or more then 15 mils 0 4 mm 0 015 in The quality of wire should not have significant variations on concentricity of wire and insulation Figure 1 4 Insulation Concentricity ACCEPTABLE UNACCEPTABLE Geometry The physical relationship between individual conductors plays a large role in drive installation Individual conduc
47. i Summary of Changes Notes Table of Contents Summary of Changes Preface Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Who Should Use This Manual 2 22 ooo P 1 Recommended Documentation 00 KK KK KK KK KK KK KK KK KK KK KK KK KK KK KK P 1 Manual Conventions 0 0 Ae liye e QAR yad cece eee eee P 2 General Preca tions l x lt a a doa 4x5 d44 ee P 2 General xe a a a dias 1 2 Input Power CableS 4 k ul L y k Pkk El ewl d a El le Siw l ki 1 10 Motor Cables 22 ss nn tenia adie A PA KWE cota ney A e A the 1 10 Cable for Discrete Drive VO 200 Z sa 2a re Be E en Er Bere 1 11 Analog Signal and Encoder Cable ML A KK KK KK KK KK KK KK KK KK K KK KK KK KK KK IH 1 12 COMMUNICA ONS s gt y4 2i nin QEW 3W A Er Da en 1 12 System Conf surat ons viii tie hen id 2 1 AC Line Voltage i oad ccna a ana aan ar oon wee N wad 2N 2 4 AC Eine Impedance Ase n ss ee Aba eb hehe ee 2 5 Surge Protection MOVs and Common Mode Capacitors 00000008 2 11 Grounding Safety Grounds 0 0 kk kk kK KK KK KK KK KK KK KK kK KK KK kk kK K k 3 1 Noise Related Gro ild8 gt a34 0 cA anan see da ara aha kre e e Ba eo e veran ed Ker k az rae 3 3 Mounting an cl rl hr ai aan tn a eee 4 1 Conduit Ent una e is sehe gr gern 4 4 Ground CONMECIONS dl A A ANS 4 6 Wire Routine a 4 9 Conduite behets os Mate at fe
48. ing 4 1 Precautions P 2 Protection MOV Surge 2 11 R RC Networks 6 4 Reactor Multiple Drives 2 9 Recommended Cable Design 1 5 Recommended Documentation P 1 Reflected Wave 5 1 Effects on Wire Types 5 1 Length Restrictions 5 2 Motor Protection 5 2 Relays Noise 6 3 6 4 Resistance Ground 2 3 RFI Filter Grounding 3 2 Routing 4 9 S Safety Grounds Building Steel 3 1 Grounding PE or Ground 3 2 Safety Grounds Grounding 3 1 Secondary Ungrounded 2 3 Shields Cable 1 6 3 7 Termination 4 15 Signal Analog Cable 1 12 Terminals 4 18 Wire 1 12 Solenoids Noise 6 3 6 4 Spacing 4 10 Wiring 4 9 4 10 Standard Installation 4 1 Suppression Noise Contracts 6 4 Inductive Loads 6 4 Motor Starters 6 4 Index 3 Motors 6 4 Relays 6 4 Solenoids 6 4 Suppressor 2 11 6 5 Surge Protection MOV 2 11 Switch Contacts Noise 6 3 6 4 System Configuration Delta Delta with Grounded Leg 2 2 Delta Wye with Grounded Wye 2 1 High Resistance Ground 2 3 TN S Five Wire System 2 4 Ungrounded Secondary 2 3 TB Terminal Block Control 4 18 Power 4 18 Signal 4 18 Temperature 1 3 Termination Conductor 4 18 Control Terminal 4 18 Power Terminals 4 18 Shield 4 15 Shield via Pigtail Lead 4 5 Signal Terminals 4 18 Via Cable Clamp 4 17 Via Circular Clamp 4 15 Via Pigtail Lead 4 16 TN S Five Wire Systems 2 4 3 2 Transient Interference Causes 6 3 Suppression 6 4 U Ungrounded Secondary 2 3 Ungrounded System Example 3 4 Unshi
49. ion It can also be directly buried or embedded in concrete Because noise containment can be affected by incidental grounding of the armor to building steel see Chapter 2 when the cable is mounted it is recommended the armored cable have an overall PVC jacket Interlocked armor is acceptable for shorter cable runs but continuous welded armor is preferred Cable with a single ground conductor is sufficient for drive sizes up to and including 200 HP 150 KW Cable with three ground conductors is recommended for drive sizes larger than 200 HP 150 kW The ground conductors should be spaced symmetrically around the power conductors The ground conductor s should be rated for full drive ampacity Cable with a Single Ground Conductor Cable with Three Ground Conductors Wire Cable Types 1 9 Figure 1 9 Armored Cable with Three Ground Conductors Optional PVC Outer Sheath Conductors with XLPE Insulation Optional Foil Copper Tape and or inner PVC Jacket A good example of acceptable cable for Type 5 installation is Anixter 7V 5003 3G which has three 3 XLPE insulated copper conductors 25 minimal overlap with the helical copper tape and three 3 bare copper grounds in PVC jacket Please note that if a terminator network or output filter is used connector insulation must be XLPE not PVC European Style Cable Cable used in many installations in Europe should conform to the CE Low
50. ir Temperature The temperature of the air around the drive If the drive is free standing or wall mounted the surrounding air temperature is room temperature If the drive is mounted inside another cabinet the surrounding air temperature is the interior temperature of that cabinet Terminator An RC network mounted at or near the motor used to reduce the amplitude and rise time of the reflected wave pulses Catalog Number 1204 TFxx THHN THWN U S designations for individual conductor wire typically 75 C or 90 C rated and with PVC insulation and nylon coating Unshielded Cable containing no braided or foil sheath surrounding the conductors Can be multi conductor cable or individual conductors Wet Locations with moisture present see Damp XLPE Cross Linked Polyethylene Glossary 4 UL Underwriters Laboratories A AC Line 2 5 Analog Signal Cable 1 12 Armored Cable 1 8 Containing Common Mode Noise 6 2 B Brake Solenoid Noise 6 3 6 4 C Cable Analog Signal 1 12 Armored 1 8 Connectors 4 5 Containing Common Mode Noise 6 2 Discrete Drive I O 1 11 Encoder 1 12 European Style 1 9 Exterior Cover 1 2 Length 1 11 Material 1 2 Recommended 1 5 Shielded 1 6 Shields 3 7 Trays 4 14 Types 1 1 1 8 Unshield Definition A 1 Unshielded 1 5 Cable Length Restrictions A 1 Cables Input Power 1 10 3 7 Capacitors Common Mode 2 11 Clamp Shield Termination 4 15 Common Mode Capacitors 2 11 Common
51. ire is being pulled through multiple 90 bends in the conduit These nicks may be a starting point for CIV leading to insulation degradation During operation the conductor heats up and a coldflow condition may occur with PVC insulation at points where the unsupported weight of the wire may stretch the insulation This has been observed at 90 bends where wire is dropped down to equipment from an above wireway This coldflow condition produces thin spots in the insulation which lowers the cable s voltage withstand capability Refer to NEC Article 100 for definitions of Damp Dry and Wet locations The U S NEC permits the use of heat resistant thermoplastic wire in both dry and damp applications Table 310 13 However PVC insulation material is more susceptible to absorbing moisture than XLPE Cross Linked polyethylene insulation material XHHN 2 identified for use in wet locations Because the PVC insulating material absorbs moisture the Corona Inception Voltage insulation capability of the damp or wet THHN was found to be less than 1 2 of the same wire when dry For this reason certain industries where water is prevalent in the environment have refrained from using THHN wire with IGBT drives Rockwell Automation strongly suggests the use of XLPE insulation for wet areas To protect the motor from reflected waves limit the length of the motor cables from the drive to the motor Each drive s user manual lis
52. iterature p 2 Overview Manual Conventions General Precautions The following words are used throughout the manual to describe an action Word Meaning Can Possible able to do something Cannot Not possible not able to do something May Permitted allowed Must Unavoidable you must do this Shall Required and necessary Should Recommended Should Not Not recommended voltage on the bus capacitors has discharged before performing any work on the drive Measure the DC bus voltage at the DC amp DC terminals of the Power Terminal Block The voltage must be zero ATTENTION To avoid an electric shock hazard verify that the Chapter 1 Wire Cable Types AC drive installations have specific requirements for cables Wire or cable selection for a drive application must consider a variety of criteria The following section covers the major issues and proper selection of cable Recommendations are made to address these issues Cable materials and construction must consider the following e Environment including moisture temperature and harsh or corrosive chemicals e Mechanical needs including geometry shielding flexibility and crush resistance e Electrical characteristics including cable capacitance charging current resistance voltage drop current rating and insulation Insulation may be the most significant of these Since drives can create voltages well in excess of line voltage the industry st
53. ive The reflection is dependent on the rise time of the drive output voltage cable characteristics cable length and motor impedance If the voltage reflection is combined with another subsequent pulse peak voltages can be at a destructive level A single IGBT drive output may have reflected wave transient voltage stresses of up to twice 2 pu or per unit the DC bus voltage between its own output wires Multiple drive output wires in a single conduit or wire tray further increase output wire voltage stress between multi drive output wires that are touching Drive 1 may have a 2 pu stress while drive 2 may simultaneously have a 2 pu stress Wires with dielectric constants greater than 4 cause the voltage stress to shift to the air gap between the wires that are barely touching This electric field may be high enough to ionize the air surrounding the wire insulation and cause a partial discharge mechanism corona to occur The electric field distribution between wires increases the possibility for corona and greater ozone production This ozone attacks the PVC insulation and produces carbon tracking leading to the possibility of insulation breakdown Based on field and internal testing Rockwell Automation has determined conductors manufactured with Poly Vinyl Chloride PVC wire insulation are subject to a variety of manufacturing inconsistencies which can lead to premature insulation degradation when used with IGBT drives Flame retar
54. l If other means of grounding are used such as ground rods the user should understand the voltage potential between ground rods in different areas of the installation Type of soil ground water level and other environmental factors can greatly affect the voltage potential between ground points if they are not bonded to each other 3 2 Grounding Grounding PE or Ground The drive safety ground PE must be connected to scheme or earth ground This is the safety ground for the drive that is required by code This point must be connected to adjacent building steel girder joist a floor ground rod bus bar or building ground grid Grounding points must comply with national and local industrial safety regulations or electrical codes Some codes may require redundant ground paths and periodic examination of connection integrity Global Drive Systems requires the PE ground to be connected to the transformer ground feeding the drive system RFI Filter Grounding Using an optional RFI filter may result in relatively high ground leakage currents Therefore the filter must only be used in installations with grounded AC supply systems and be permanently installed and solidly grounded to the building power distribution ground Ensure the incoming supply neutral is solidly connected to the same building power distribution ground Grounding must not rely on flexible cables or any plug or socket that may be accidentally disconnected Some codes may re
55. lar section of 360 bonding as shown in Commercial Cable Clamp Heavy Duty on page 4 15 It has the advantage of covering a wide variety of cable diameters and drilling mounting is not required Its disadvantages are cost and availability in all areas Figure 4 13 Commercial Cable Clamp Heavy Duty Plain copper saddle clamps as shown in Figure 4 14 on page 4 16 are sold in many areas for plumbing purposes but are very effective and available in a range of sizes They are low cost and offer good strain relief as well You must drill mounting holes to use them 4 16 Practices Figure 4 14 Plain Copper Saddle Clamp Shield Termination via Pigtail Lead If a shield terminating connector is not available the ground conductors and or shields must be terminated to the appropriate ground terminal If necessary use a compression fitting on the ground conductor s or shield together as they leave the cable fitting Pigtail termination is the least effective method of noise containment It is not recommended if e the cable length is greater than 1 m 39 in or extends beyond the panel e being used in very noisy areas e the cables are for very noise sensitive signals for example registration or encoder cables e strain relief is required If a pigtail is used pull and twist the exposed shield after separation from the conductors To extend the length solder a flying lead to the braid Practices 4 17 Shield Ter
56. le 310 13 However PVC insulation material is more susceptible to absorbing moisture than XLPE Cross Linked polyethylene insulation material XHHW 2 identified for use in wet locations Because the PVC insulating material absorbs moisture the corona inception voltage CIV insulation capability of the damp or wet THHN was found to be less than Y2 of the same wire when dry For this 39 Practices 4 19 reason certain industries where water is prevalent in the environment have refrained from using THHN wire with IGBT drives Belden 29500 style cable is a PVC jacketed shielded type TC with XLPE conductor insulation designed to meet NEC code designation XHHW 2 use in wet locations per the U S NEC Table 310 13 Based on Rockwell Automation research tests have determined this cable is notably superior to loose wires in dry damp and wet applications and can significantly reduce capacitive coupling and common mode noise Other cable types for wet locations include continuous welded armor cables or CLX designation 4 20 Practices Notes Description Effects On Wire Types Chapter 5 Reflected Wave This chapter discusses the reflected wave phenomenon and its impact on drive systems The inverter section of a drive does not produce sinusoidal voltage but rather a series of voltage pulses created from the DC bus These pulses travel down the motor cables to the motor The pulses are then reflected back to the dr
57. m2 18AWG Combined Belden 9773 9774 0 750 mm 18AWG or equivalent 4 individually shielded pair equivalent AWG for power equivalent 1 Belden 9730 is 3 indivi 2 Belden 8790 is 1 shi 3 Belden 9892 is 3 indiv e Ifthe wires are short a not be necessary but ded pair is always recommended Serial RS232 485 300V 75 90 C 167 194 F dually shielded pairs 2 channel plus power If 3 channel is required use Belden 9728 or idually shielded pairs 3 channel 0 33 mm 22 AWG plus 1 shielded pair 0 5 mm 20 Belden 9773 is 3 individually shielded pairs 2 channel plus power If 3 channel is required use Belden 9774 or nd contained within a cabinet which has no sensitive circuits the use of shielded wire may Standard practices for serial communications wiring should be followed Belden 3106A or equivalent that contains one twisted pair and one signal common is recommended for RS232 Recommended cable for RS485 is two individually shielded twisted pairs System Configurations Chapter 2 Power Distribution This chapter discusses different power distribution schemes and factors which affect drive performance The type of transformer and the connection configuration feeding a drive plays an important role in its performance and safety The following is a brief description of some of the more common configurations and a discussion of their virtues and shortco
58. mination via Cable Clamp Standard Cable Grounding Cable glands are a simple and effective method for terminating shields while offering excellent strain relief They are only applicable when entry is through a cabinet surface or bulkhead The cable connector selected must provide good 360 contact and low transfer impedance from the shield or armor of the cable to the conduit entry plate at both the motor and the drive or drive cabinet for electrical bonding SKINTOP MS SC MS SCL cable grounding connectors and NPT PG adapters from LAPPUSA are good examples of standard cable clamp shield terminating gland Armored Cable Armored cable can be terminated in a similar manner to standard cable The Tek Mate Fast Fit cable clamp by O Z Gedney is a good example of an armored cable terminator IN y 4 18 Practices Conductor Termination Moisture Terminate power motor and control connections to the drive terminal blocks User manuals list minimum and maximum wire gauges tightening torque for terminals and recommended lug types if stud connections are provided Use a connector with 3 ground bushings when using a cable with 3 ground conductors Bending radii minimums per the applicable electrical code should be followed Power TB Power terminals are normally fixed non pull apart and can be cage clamps barrier strips or studs for ring type crimp lugs depending on the drive style and rating Cage clamp
59. mings Delta Wye with Grounded Wye Neutral A Delta Wye with Grounded Wye Neutral is the most common type of distribution system It provides re balancing of unbalanced voltage with a 30 degree phase shift The grounded neutral provides a direct path for common mode current caused by the drive output see Chapter 3 and Chapter 6 Rockwell Automation strongly recommends the use of grounded neutral systems for the following reasons Controlled path for common mode noise current Consistent line to ground voltage reference which minimizes insulation stress Accommodation for system surge protection schemes 2 2 Power Distribution Delta Delta with Grounded Leg or Four Wire Connected Secondary Delta DE Delta Delta with Grounded Leg or Four Wire Connected Secondary Delta 1s a common configuration providing voltage re balancing with no phase shift between input and output The grounded center tap provides a direct path for common mode current caused by the drive output 3 Phase Open Delta with 1 Phase Center Tapped Phase Loads Single Phase Loads O Single Phase Loads Three Phase Open Delta with 1 Phase Center Tapped is a configuration providing a 3 phase delta transformer with one side tapped This tap the neutral is connected to earth The configuration is called the antiphase grounded neutral system The open delta transformer connection is limited to 58 of the 240V single phase t
60. mon mode noise current Consistent line to ground voltage reference which minimizes insulation stress Accommodation for system surge protection schemes QQ Grounding 3 5 Figure 3 4 Fully Grounded Scheme Earth Ground Potential The installation and grounding practices to reduce common mode noise issues can be categorized into three ratings The scheme used must weigh additional costs against the operating integrity of all scheme components If no sensitive equipment is present and noise is not be an issue the added cost of shielded cable and other components may not be justified Acceptable Grounding Practices The scheme shown below is an acceptable ground layout for a single drive installation However conduit may not offer the lowest impedance path for any high frequency noise If the conduit is mounted so that it contacts the building steel it is likely that the building steel will offer a lower impedance path and allow noise to inhabit the ground grid Connection to Drive Structure MOTOR FRAME or Optional Cabinet Via Conduit Connector CONDUIT INPUT TRANSFORMER lt lt q Connection to Ground Grid Girder or Ground Rod Connection to OPTIONAL ENCLOSURE Cabinet Ground Bus or Directly to Drive PE Terminal Frame Ground BUILDING GROUND POTENTIAL 3 6 Grounding Effective Grounding Practices This scheme replaces the conduit with shielded or armored cable th
61. n nf ln WE ee de 4 13 Cable Trays cuore 4 14 Shield Termination ci tgp Sela Hs Big eG hg a Pie ble ae 4 15 Conductor Terminal 4 18 MOISLUTE KEN DU AOE A AE E O BALA sah AU ct mM 4 18 Description 5es s Kn ave ana nn aa Maas hen wees asin 5 1 Effects On Wire Types ds ori Kela ipsa ia e Lene tn an See ae 5 1 Length Restrictions For Motor Protection 00 eee KK KK KK KK KK KK eee 5 2 What Causes Common Mode Noise kk kk kk kk KK KK KK KK KK kk kk kk eens 6 1 Containing Common Mode Noise With Cabling KK KK KK KK KK KK KK 6 2 How Electromechanical Switches Cause Transient Interference 6 3 How to Prevent or Mitigate Transient Interference from Electromechanical Switches 6 4 Enclosure Lighting x n Wl se se rs rn Pk l 6 7 Appendix A Glossary Index Who Should Use This Manual Recommended Documentation Overview Preface The purpose of this manual is to provide you with the basic information needed to properly wire and ground Pulse Width Modulated PWM AC drives This manual is intended for qualified personnel who plan and design installations of Pulse Width Modulated PWM AC drives The following publications provide general drive information Title Publication Available Installing Operating and Maintaining D2 3115 2 Engineered Drive Systems Reliance Electric Safety Guidelines for the Application Installation SGI 1 1 www
62. ncy common mode coupled from output to ground noise currents These currents cause sensitive equipment to malfunction if they are allowed to propagate Path for Common Mode Current MOTOR FRAME back Device Path for Common Mode Current Path for Common Mode Current Path for Common Mode Current SYSTEM GROUND Path for Common Mode Current 3 4 Grounding The grounding scheme can greatly affect the amount of noise and its impact on sensitive equipment The power scheme is likely to be one of three types e Ungrounded Scheme e Scheme with High Resistance Ground e Fully Grounded Scheme An ungrounded scheme as shown in Figure 3 2 does not provide a direct path for the common mode noise current causing it to seek other uncontrolled paths This causes related noise issues Figure 3 2 Ungrounded Scheme De Earth Ground Potential A scheme with a high resistance ground shown in Figure 3 3 provides a direct path for common mode noise current like a fully grounded scheme Designers who are concerned with minimizing ground fault currents commonly choose high resistance ground schemes Figure 3 3 Scheme with High Resistance Ground Earth Ground Potential A fully grounded scheme shown in Figure 3 4 provides a direct path for common mode noise currents Rockwell Automation strongly recommends the use of grounded neutral systems for the following reasons Controlled path for com
63. ns to Ground Stud or Bolts Practices 4 9 Wire Routing General When routing wiring to a drive separate high voltage power and motor leads from I O and signal leads To maintain separate routes route these in separate conduit or use tray dividers Table 4 A Cable and Wiring Recommendations Minimum Spacing in inches between Levels in Wiring Steel Conduits Cable Trays Spacing Category Level Signal Definition Signal Examples 1 2 3 4 5 6 7 8 9 10 11 Notes Power 1 AC Power 600V or greater 2 3kV 3 Ph AC Lines 0 3 9 3 9 3 18 Refer to Refer to Spacing Spacing Note6 Notes 1 2 and 5 2 AC Power less than 600V 460V 3 Ph AC Lines 3 9 0 3 6 3 12 Refer to Refer to 3 AC Power AC Motor Spacing Spacing 4 Dynamic Brake Cables Refer to Spacing Note Note Notes 1 2 7 and 5 Control 5 115V ac dc Logic Relay Logic PLC I O 13 9 3 6 0 3 9 Refer to Refer to Motor Thermostat Spacing Spacing 115V ac Power Power Supplies Note6 Notes 1 2 Instruments and 5 6 24V ac dc Logic PLC 1 0 Signal 7 Analog Signals DC Supplies Reference Feedback 3 18 3 12 3 9 0 1 3 Refer to Process Signal 5 to 24V DC Spacing Digital Low Speed TTK Notes 2 3 8 Digital High Speed 1 0 Encoder Counter 4and 5 Pulse Tach Signal 9 Serial Communication RS 232 422 to Refer to Spacing Note 6 1 3 0 Comm Terminals Printers 11 Serial Communication ControlNet greater
64. op etc Dry Dry locations per Per NEC Article 100 or local code dv dt The rate of change of voltage over time Fill Rates The maximum number of conductors allowed in a conduit as determined by local state or national electrical code Fixed Geometry Cable whose construction fixes the physical position of each conductor within the overall coating usually with filler material that prevents individual conductors from moving IGBT Insulated Gate Bi Polar Transistor The typical power semi conductor device used in most PWM AC drives today mil 0 001 inches MOV Metal Oxide Varistor NEC United States National Electric Code NFPA70 Peak Cable Charging Current The current required to charge capacitance in motor cable This capacitance has various components conductor to shield or conduit conductor to conductor motor stator to motor frame Glossary 3 PVC Polyvinyl Chloride typically thermoplastic RWR Reflected Waver Reducer an RL network mounted at or near the drive used to reduce the amplitude and rise time of the reflected wave pulses Cat No 1204 RWR2 09 B or 1204 RWR2 09 C Shielded Cable containing a foil or braided metal shield surrounding the conductors Usually found in multi conductor cable Shield coverage should be at least 15 Signal Individual hard wired analog inputs or outputs typically used to issue reference commands or process information to or from the drive Surrounding A
65. pment or software described in this manual Reproduction of the contents of this manual in whole or in part without written permission of Rockwell Automation Inc is prohibited Throughout this manual when necessary we use notes to make you aware of safety considerations WARNING Identifies information about practices or circumstances that can cause an explosion in a hazardous environment which may lead to personal injury or death property damage or economic loss gt Important Identifies information that is critical for successful application and understanding of the product ATTENTION Identifies information about practices or circumstances that can lead to personal injury or death property damage or economic loss Attentions help you identify a hazard avoid a hazard and recognize the consequences Shock Hazard labels may be located on or inside the equipment e g drive or motor to alert people that dangerous voltage may be present Burn Hazard labels may be located on or inside the equipment e g drive or motor to alert people that surfaces may be at dangerous temperatures gt gt VTAC 9 and VS Utilities are registered trademarks of Rockwell Automation Inc Summary of Changes This is the initial release of the VTAC Wiring and Grounding Guidelines for Pulse Width Modulated AC Drives publication VTAC INO02 Changes made to subsequent versions of this manual will be listed on this page i
66. quire redundant ground connections Periodically check the integrity of all connections Refer to the instructions supplied with the filter Grounding Motors The motor frame or stator core must be connected directly to the drive PE connection with a separate ground conductor It is recommended that each motor frame be grounded to building steel at the motor Refer to Cable Trays in Chapter 4 for more information Grounding and TN S Five Wire Systems Do not connect ground to neutral within a system cabinet when using a TN S five wire distribution system The neutral wire is a current conducting wire There is a single connection between ground and neutral typically in the distribution system TN S five wire distribution systems are common throughout Europe with the exception of the United Kingdom and Germany Leg to leg voltage commonly at 400V powers three phase loads Leg to neutral voltage commonly at 230V powers single phase loads Grounding 3 3 Figure 3 1 Cabinet Grounding with a TN S Five Wire System Input Transformer System Cabinet AC Drive L2 L3 PEN or N PE Single Phase Device e fe o Cabinet Ground Bus Noise Related Grounds It is important to take care when installing PWM AC drives because output can produce high freque
67. r to Table 1 A on page 1 5 Figure 1 8 Type 2 Installation Shielded Cable with Brake Conductors 1 8 Wire Cable Types Type 3 Installation These cables have 3 XLPE insulated copper conductors 25 minimal overlap with helical copper tape and three 3 bare copper grounds in PVC jacket TIP Other types of shielded cable are available but the selection of these types may limit the allowable cable length Particularly some of the newer cables twist 4 conductors of THHN wire and wrap them tightly with a foil shield This construction can greatly increase the cable charging current required and reduce the overall drive performance Unless specified in the individual distance tables as tested with the drive these cables are not recommended and their performance against the lead length limits supplied 1s not known For more information about motor cable lead restrictions refer Appendix A Conduit on page 4 13 Moisture on page 4 18 and Effects On Wire Types on page 5 1 on THHN wire Armored Cable Cable with continuous aluminum armor is often recommended in drive system applications or specific industries It offers most of the advantages of standard shielded cable and also combines considerable mechanical strength and resistance to moisture It can be installed in concealed and exposed manners and removes the requirement for conduit EMT in the installat
68. ransformer rating Closing the delta with a third single phase 240V transformer allows full rating for the two single phase 240V transformers The phase leg opposite the midpoint has an elevated voltage when compared to earth or neutral The hottest high leg must be positively identified throughout the electrical system It should be the center leg in any switch motor control three phase panel board etc The NEC requires orange color tape to identify this leg Power Distribution 2 3 Ungrounded Secondary AY AL Grounding the transformer secondary is essential to the safety of personnel and safe operation of the drive Leaving the secondary floating allows dangerously high voltages between the chassis of the drive and the internal power structure components Exceeding the voltage rating of the drive s input MOV Metal Oxide Varistor protection devices could cause a catastrophic failure In all cases the input power to the drive should be referenced to ground If the system is ungrounded other general precautions such as a system level ground fault detector or system level line to ground suppressor may be necessary or an isolation transformer must be considered with the secondary of the transformer grounded Refer to local codes regarding safety requirements Also refer to Surge Protection MOVs and Common Mode Capacitors on page 2 10 High Resistance Ground AN Grounding the wye secondary neutral through a resistor is
69. styles may require a non standard screwdriver Crimp lugs will require a crimping tool On smaller sizes a stripping gauge may be provided on the drive to assist in the amount of insulation to remove Normally the three phase input is not phase sensitive That is the sequence of A B C phases has no effect on the operation of the drive or the direction of motor rotation Control TB Control terminal blocks are either pull apart or fixed non pull apart Terminals will be either spring clamp type or barrier strip A stripping gauge may be provided on the drive to assist in the amount of insulation to remove Some control connections such as analog input and output signals are polarity sensitive Consult the applicable user manual for correct connection Signal TB If an encoder or tachometer feedback is used a separate terminal block or blocks may be provided Consult the user manual for these phase sensitive connections Improper wiring could lead to incorrect drive operation Cables terminated here are typically shielded and the signals being carried are generally more sensitive to noise Carefully check the user manual for recommendations on shield termination Some shields can be terminated at the terminal block and others will be terminated at the entry point Refer to NEC Article 100 for definitions of Damp Dry and Wet locations The U S NEC permits the use of heat resistant thermoplastic wire in both dry and damp applications Tab
70. tage returns to zero Charging and arcing continues until the distance between the contacts is sufficient to provide insulation The arcing radiates noise at an energy levels and frequencies that disturb logic and communication circuits If the power source is periodic like AC power you can reduce the interference by opening the contact when the current waveform crosses zero Opening the circuit farther from zero elevates the energy level and creates more interference 6 4 Electromagnetic Interference How to Prevent or Mitigate The most effective way to avoid this type of transient interference is to use Transient Interference from a device like an Allen Bradley Bulletin 156 contactor to switch inductive Electromechanical Switches AC loads These devices feature zero cross switching Al A2 11 T1 O Bulletin 156 Contactor AC Load O Putting Resistive Capacitive RC networks or Voltage Dependant Resistors Varistors across contacts will mitigate transient interference Make sure to select components rated to withstand the voltage power and frequency of switching for your application AC Load AC Load AC Electromagnetic Interference 6 5 A common method for mitigating transient interference is to put a diode in parallel with an inductive DC load or a suppressor in parallel with an inductive AC load Again make sure to select components rated to
71. the lamp and its switch use a metal encased switch install a filter between the switch and the power line or shield the power line cable 00 O o a TU ac power Shielding grid Shielded Metel encased Line filter or over lamp cable switch shielded power line 6 8 Electromagnetic Interference Notes Appendix A Motor Cable Length Restrictions Tables The distances listed in each table are valid only for specific cable constructions and may not be accurate for lesser cable designs particularly 1f the length restriction is due to cable charging current indicated in tables by shading When choosing the proper cable note the following definitions Unshielded Cable e Tray cable fixed geometry without foil or braided shield but including an exterior cover e Individual wires not routed in metallic conduit Definition Shielded Cable e Individual conductors routed in metallic conduit e Fixed geometry cables with foil or braided shield of at least 75 coverage e Belden 295xx or Alcatel C1202 needed as indicated by individual table for specific drive e Continuous weld or interlocked armored cables with no twist in the conductors may have and optional foil shield Important Certain shielded cable constructions may cause excessive cable charging currents and may interfere with proper application performance particularly on smaller drive ratings Shielded cables that do not maintain a fixed geome
72. tomation may recommend that the same type of shielded cable specified for the AC motors be used between the drive and transformer Check the individual user manuals or system schematic note sheets for specific additional requirements in these situations The majority of recommendations regarding drive cable address issues caused by the nature of the drive output A PWM drive creates AC motor current by sending DC voltage pulses to the motor in a specific pattern These pulses affect the wire insulation and can be a source of electrical noise The rise time amplitude and frequency of these pulses must be considered when choosing a wire cable type The choice of cable must consider 1 The effects of the drive output once the cable is installed 2 The need for the cable to contain noise caused by the drive output 3 The amount of cable charging current available from the drive 4 Possible voltage drop and subsequent loss of torque for long wire runs Keep the motor cable lengths within the limits set by the drive s user manual Various issues including cable charging current and reflected wave voltage stress may exist If the cable restriction is listed because of excessive coupling current apply the methods to calculate total cable length as shown in Figure 1 11 on page 1 11 If the restriction is due to voltage reflection and motor protection tabular data is available Refer to Appendix A for exact distances allowed
73. tors in conduit or cable tray have no fixed relationship and are subject to a variety of issues including cross coupling of noise induced voltages excess insulation stress and others Fixed geometry cable cable that keeps the spacing and orientation of the individual conductors constant offers significant advantages over individual loose conductors including reducing cross coupling noise and insulation stress Three types of fixed geometry multi conductor cables are discussed below Unshielded shielded and armored Wire Cable Types 1 5 Table 1 A Recommended Cable Design Type Max Wire Size Where Used Rating Type Description Typei 2 AWG Standard Installations 600V 90 C 194 F Four tinned copper conductors with XLPE insulation 100 hp or less XHHW2 RHW 2 Type2 2 AWG Standard Installations 600V 90 C 194 F Four tinned copper conductors with XLPE insulation plus 100 hp or less with Brake RHH RHW 2 one 1 shielded pair of brake conductors Conductors Type3 500 MCM AWG Standard Installations Tray rated 600V 90 C 194 F Three tinned copper conductors with XLPE insulation 150 hp or more RHH RHW 2 and 3 bare copper grounds and PVC jacket Type 4 1500 MCM AWG Water Caustic Chemical Tray rated 600V 90 C 194 F Three bare copper conductors with XLPE insulation and Crush Resistance RHH RHW 2 three copper grounds on 10 AWG and smaller Acceptable in Class I amp Il Division 4 II locations Type 5 500
74. tromagnetic Interference 6 3 As a general rule IF the distance between the drive and motor or the distance between drive and input transformer is greater than 75 feet AND TF sensitive circuits with leads greater then 75 feet such as encoders analog or capacitive sensors are routed in or out of the cabinet near the drive or transformer THEN Common mode chokes should be installed Electromechanical contacts cause transient interference when switching inductive loads such as relays solenoids motor starters or motors Drives as well as other devices having electronic logic circuits are susceptible to this type of interference Examine the following circuit model for a switch controlling an inductive load Both the load and the wiring have inductance which prevents the current from stopping instantly when the switch contacts open There is also stray capacitance in the wiring Wiring f Load Capacitance ind ctanc Load AD YY Wiring Inductance Interference occurs when the switch opens while it is carrying current Load and cable inductance prevents the current from immediately stopping The current continues to flow and charges the capacitance in the circuit The voltage across the switch contacts VC rises as the capacitance charges This voltage can reach very high levels When the voltage exceeds the breakdown voltage for the space between the contacts an arc occurs and the vol
75. try but rather twist the conductors and tightly wrap the bundle with a foil shield may cause unnecessary drive tripping Unless specifically stated in the table the distances listed ARE NOT applicable to this type of cable Actual distances for this cable type may be considerably less Type A Motor e No phase paper or misplaced phase paper e Lower quality insulation systems e Corona inception voltages between 850 and 1000 volts Type B Motor e Properly placed phase paper e Medium quality insulation systems e Corona inception voltages between 1000 and 1200 volts 1488V Motor e Meets NEMA MG 1 1998 section 31 standard e Insulation can withstand voltage spikes of 3 1 times rated motor voltage due to inverter operation Reliance Electric Inverter Rated Motor e Motor designed to meet or exceed the requirements of the Federal Energy Act of 1992 e Optimized for variable speed operation and include premium inverter grade insulation systems which meet or exceed NEMA MGI Part 31 40 4 2 A 2 Table A A VTAC 9 Drives 480V No External Devices Feet Meters Motor Cable Length Restrictions Tables
76. ts the lead length limitations based on drive size and the quality of the insulation system in the chosen motor If the distance between drive and motor must exceed these limits contact the local office or factory for analysis and advice Refer to Appendix A for complete tables Chapter 6 Electromagnetic Interference This chapter discusses types of electromagnetic interference and its impact on drive systems What Causes Common Faster output dv dt transitions of IGBT drives increase the possibility for Mode Noise increased Common Mode CM electrical noise Common Mode Noise is a type of electrical noise induced on signals with respect to ground MOTOR FRAME ES Feed R back Devici i Path for Common Mode Current Path for Common Mode Current Path for Common Mode Current Path for Common Mode Current SYSTEM GROUND Path for Common Mode Current There is a possibility for electrical noise from drive operation to interfere with adjacent sensitive electronic equipment especially in areas where many drives are concentrated Generating common mode currents by varying frequency inverters is similar to the common mode currents that occur with DC drives Although AC drives produce a much higher frequency then DC drives 250 kHz 6MHz Inverters have a greater potential for exciting circuit resonance because of very fast turn on switches causing common mode currents to look for the lowest impedance
77. uch as Belden 8770 or equiv 3 conductor shielded 1 12 Wire Cable Types Analog Signal and Encoder Cable Communications Always use shielded cable with copper wire Wire with insulation rating of 300V or greater is recommended Analog signal wires should be separated from power wires by at least 0 3 meters 1 foot It is recommended that encoder cables be run in a separate conduit If signal cables must cross power cables cross at right angles Terminate the shield of the shielded cable as recommended by manufacturer of the encoder or analog signal device Table 1 C Recommended Signal Wire Signal Type Where Used Wire Type s Description Minimum Insulation Rating AZ Tb Standard Analog I O Belden 8760 9460 or equiv 0 750 mm 18AWG twisted pair 100 shield with drain Remote Pot Belden 8770 or equiv 0 750 mm 18AWG 3 cond shielded Encoder Pulse I O Combined Belden 9730 or 0 196 mm 24AWG Less 30 5 m 100 ft equivalent 1 individually shielded Encoder Pulse I O Signal Belden 9730 9728 0 196 mm 24AWG 30 5 m 100 ft to or equivalent individually shielded 152 4m 500ft Bower Belden 8790 2 10 750 mm2 18AWG Combined Belden 9892 0 330 mm or 0 500 mm 2 Encoder Pulse I O Signal Belden 9730 9728 0 196 mm 24AWG 152 4 m 500 ft to or equivalent individually shielded 259 1 m 850t power Belden 8790 10 750 m
78. und Bus or Directly to Drive PE Terminal BUILDING GROUND POTENTIAL Grounding 3 7 Cable Shields Motor and Input Cables Shields of motor and input cables must be bonded at both ends to provide a continuous path for common mode noise current Control and Signal Cables Shields of control cables should be connected at one end only The other end should be cut back and insulated The shield for a cable from one cabinet to another must be connected at the cabinet that contains the signal source The shield for a cable from a cabinet to an external device must be connected at the cabinet end unless specified by the manufacturer of the external device Never connect a shield to the common side of a logic circuit this will introduce noise into the logic circuit Connect the shield directly to a chassis ground Shield Splicing Figure 3 5 Spliced Cable Using Shieldhead Connector If the shielded cable needs to be stripped it should be stripped back as little as possible to ensure that continuity of the shield is not interrupted Avoid splicing motor power cables when ever possible Ideally motor cables should run continuously between the drive and motor e terminals The most common reason for interrupted cable shield is to incorporate an at the motor disconnect switch In these cases the preferred method of splicing is to use fully shielded bulkhead connectors Single Point
79. wever not all applications allow the use of magnetic steel conduit Stainless steel or PVC may be required Conduit other than magnetic steel will not provide the same level of shielding for magnetic fields induced by the motor and input power currents Conduit must be installed so as to provide a continuous electrical path through the conduit itself This path can become important in the containment of high frequency noise To avoid nicking use caution when pulling the wire Insulation damage can occur when nylon coated wiring such as THHN or THWN is pulled through conduit particularly 90 bends Nicking can significantly reduce or remove the insulation Use great care when pulling nylon coated Do not use water based lubricants with nylon coated wire such as THHN Do not route more than 3 sets of motor cables in one conduit Maintain the proper fill rates per the applicable electrical codes Do not rely on the conduit as the ground return for a short circuit Route a separate ground wire inside the conduit with the motor or input power wires 4 14 Practices Cable Trays When laying cable in cable trays do not randomly distribute them Power cables for each drive should be bundled together and anchored to the tray A minimum separation of one cable width should be maintained between bundles to reduce overheating and cross coupling Current flowing in one set of cables can induce a hazardous voltage and or excessive noise on the c

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