Power Factor Capacitors & Harmonic Filters 37.0-1 June 2006 Power Factor Capacitors & Harmonic Filters Sheet 1623 CA08104001E Contents Power Factor Capacitors & Harmonic Filters Capacitor Application Considerations Capacitor Selection 37.0-2 NEC Code Requirements for Capacitors 37.0-2 Capacitor Switching Devices 37.0-3 Installing Capacitors in a Plant Distribution System 37.0-5 Locating Capacitors on Reduced Voltage and Multi-Speed Motor Starters 37.0-6 Harmonic Considerations 37.0-7 Eliminating Harmonic Problems — Passive and Switched Harmonic Filters 37.0-8 Motor Power Factor Correction 37.0-9 Capacitor Application Tables for Motors 37.0-10 600 Volts ac and Below Fixed Low Voltage Capacitors and Filters Power Factor Correction Capacitors 37.1-1 Harmonic Filtering 37.1-1 UNIPAK Filter 37.1-2 UNIPAK Low Voltage Fixed Capacitor Banks 37.1-4 Dimensions 37.1-5 UNIPAK Low Voltage Fixed Harmonic Filters 37.1-6 UNIPUMP Power Factor Correction Capacitors 37.1-7 Automatic Power Factor Correction Systems AUTOVAR 300 Wall-Mounted up to 300 kvar 37.2-1 AUTOVAR 600 Floor-Mounted up to 1200 kvar 37.2-2 AUTOVAR Filter 37.2-3 AUTOVAR 300 Dimensions 37.2-4 AUTOVAR 600 Dimensions 37.2-5 AUTOVAR Switched Harmonic Filter Dimensions 37.2-6 Active Harmonic Filter-Harmonic Correction Unit (480 V Max.) General Description 37.3-1 Dimensions 37.3-3 Transient-Free Static Switching Power Factor Correction Units — Low Voltage General Description 37.4-1 Product Configurations 37.4-2 Metal-Enclosed — Medium Voltage UNIVAR Fixed PFC Unit General Description 37.5-1 Layout Dimensions 37.5-3 AUTOVAR Metal-Enclosed PFC System General Description 37.6-1 Layout Dimensions 37.6-8 Specifications For complete product specifications in CSI format, see Eaton’s Cutler-Hammer Product Specification Guide on enclosed CD-ROM: 1995 CSI Format: Fixed Power Factor Correction Equipment — LV(UNIVAR) Section 16280A Switched Power Factor Correction Equipment — LV (AUTOVAR) Section 16280B Switched Harmonic Filter Equipment — LV (AUTOVAR) Section 16280C Switched Power Factor Correction — MV Section 16280D Switched Capacitor & Harmonic Filter Equipment — MV (AUTOVAR) Section 16280E 2004 CSI Format: Fixed Power Factor Correction Equipment — LV(UNIVAR) Section 26 35 33.11 Switched Power Factor Correction Equipment — LV (AUTOVAR) Section 26 35 33.13 Switched Harmonic Filter Equipment — LV (AUTOVAR) Section 26 35 26.15 Switched Power Factor Correction — MV Section 26 35 33.17 Switched Capacitor & Harmonic Filter Equipment — MV (AUTOVAR) Section 26 35 33.19 For more information visit: www.EatonElectrical.com 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 37.0-2 Power Factor Capacitors & Harmonic Filters Application Considerations June 2006 Sheet 1624 Capacitors 22 23 24 25 26 27 28 29 30 31 32 There are two basic types of capacitor installations: individual capacitors on linear or sinusoidal loads, and banks of fixed or automatically switched capacitors at the feeder or substation 35 36 37 38 39 40 41 42 ■ ■ ■ Individual vs Banked Installations ■ Improved motor performance due to more efficient power utilization and reduced voltage drops Motors and capacitors can be easily relocated together Easier to select the right capacitor for the load Reduced line losses Increased system capacity Advantages of bank installations at the feeder or substation: Advantages of individual capacitors at the load: ■ Lower cost per kvar ■ Total plant power factor improved — reduces or eliminates all forms of kvar charges ■ Automatic switching ensures exact amount of power factor correction, eliminates overcapacitance and resulting overvoltages ■ Complete control Capacitors cannot cause problems on the line during light load conditions ■ No need for separate switching Motor always operates with capacitor Table 37.0-1 Summary of Advantages/Disadvantages of Individual, Fixed Banks, Automatic Banks, Combination Method Advantages Disadvantages Individual Capacitors Most technically efficient, most flexible Higher installation and maintenance cost Fixed Bank Most economical, fewer installations Less flexible, requires switches and/or circuit breakers Automatic Bank Best for variable loads, prevents overvoltages, low installation cost Higher equipment cost Combination Most practical for larger numbers of motors Least flexible 33 34 ■ Capacitor Selection Selection Criteria Load Size The selection of the type of capacitor installation will depend on advantages and disadvantages of each type and several plant variables, including load type, load size, load constancy, load capacity, motor starting methods and manner of utility billing Facilities with large loads benefit from a combination of individual load, group load and banks of fixed and automatically-switched capacitor units A small facility, on the other hand, may require only one capacitor at the control board Load Type Sometimes, only an isolated trouble spot requires power factor correction in applications such as welding machines, induction heaters or dc drives If a particular feeder serving a low power factor load is corrected, it may raise overall plant power factor enough that additional capacitors are unnecessary If a facility has many large motors, 50 hp and above, it is usually economical to install one capacitor per motor and switch the capacitor and motor together If there are many small motors, 1/2 to 25 hp, motors can be grouped with one capacitor at a central point in the distribution system Often, the best solution for plants with large and small motors is to use both types of capacitor installations Load Constancy Load Capacity If feeders or transformers are overloaded, or to add additional load to already loaded lines, correction must be applied at the load If a facility has surplus amperage, capacitor banks can be installed at main feeders If load varies a great deal, automatic switching is probably the answer Utility Billing The severity of the local electric utility tariff for power factor will affect payback and ROI In many areas, an optimally designed power factor correction system will pay for itself in less than two years National Electric Code Requirements for Capacitors Nameplate kvar: Tolerance +15, - 0% Discharge Resistors: Capacitors rated at 600 volts and less must reduce the charge to less than 50 volts within minute of de-energization Capacitors rated above 600 volts must reduce the charge within minutes Continuous Operation: Up to 135% rated (nameplate) kvar, including the effects of 110% rated voltage (121% kvar), 15% capacitance tolerance and harmonic voltages over the fundamental frequency (60 Hz) Dielectric Strength Test: Twice the rated ac voltage (or a dc voltage 4.3 times the ac rating for non-metallized systems) Overcurrent Protection: Fusing between 1.65 and 2.5 times rated current to protect case from rupture Does not preclude NECா requirement for overcurrent protection in all three ungrounded conductors Note: When capacitor is connected to the load side of the motor overcurrent protection, fused disconnects or breaker protection is not required Fuses are recommended for all other indoor applications If a facility operates around-the-clock and has a constant load demand, fixed capacitors offer the greatest economy If load is determined by eight-hour shifts five days a week, utilize switched units to decrease capacitance during times of reduced load 43 For more information visit: www.EatonElectrical.com CA08104001E June 2006 Power Factor Capacitors & Harmonic Filters Application Considerations 37.0-3 Sheet 1625 Switching Devices Capacitor Switching Devices We recommend that such application be referred to Eaton Medium Voltage Capacitor Switching A breaker specified for capacitor switching should include as applicable: Capacitance switching constitutes severe operating duty for a circuit breaker At the time the breaker opens at near current zero the capacitor is fully charged After interruption, when the alternating voltage on the source side of the breaker reaches its opposite maximum, the voltage that appears across the contacts of the open breaker is at least twice the normal peak lineto-neutral voltage of the circuit If a breakdown occurs across the open contact the arc is re-established Due to the circuit constants on the supply side of the breaker, the voltage across the open contact can reach three times the normal line-to-neutral voltage After it is interrupted and with subsequent alternation of the supply side voltage, the voltage across the open contact is even higher Rated maximum voltage ANSI Standard C37.06 (indoor oilless circuit breakers) indicates the preferred ratings of Eaton’s Cutler-Hammerா Type VCP-W vacuum breaker For capacitor switching careful attention should be paid to the notes accompanying the table The definition of the terms are in ANSI Standard C37.04 Article 5.13 (for the latest edition) The application guide ANSI/IEEE Standard C37.012 covers the method of calculation of the quantities covered by C37.06 Standard Note that the definitions in C37.04 make the switching of two capacitors banks in close proximity to the switchgear bus a back-to-back mode of switching This classification requires a definite purpose circuit breaker (breakers specifically designed for capacitance switching) Rated frequency Rated open wire line charging switching current Rated isolated cable charging and shunt capacitor switching current Rated back-to-back cable charging and back-to-back capacitor switching current Rated transient overvoltage factor Rated transient inrush current and its frequency Rated interrupting time Rated capacitive current switching life 10 Grounding of system and capacitor bank Loadbreak interrupter switches are permitted by ANSI/IEEE Standard C37.30 to switch capacitance but they must have tested ratings for the purpose Refer to Cutler-Hammer Type MVS ratings Low Voltage Capacitor Switching Circuit breakers and switches for use with a capacitor must have a current rating in excess of rated capacitor current to provide for overcurrent from overvoltages at fundamental frequency and harmonic currents The following percent of the capacitor-rated current should be used as a general guideline: Fused and unfused switches 165% Molded case breaker or equivalent 150% DSII power circuit breakers 135% Magnum DS power circuit breaker 135% Contactors: Open type 135% Enclosed type 150% The NEC, Section 460-8(c)(4), requires the disconnecting means to be rated not less than 135% of the rated capacitor current (for 600 V and below) See Page 37.0-4 for more information on Low Voltage Capacitor Switching Devices CA08104001E For more information visit: www.EatonElectrical.com Projects which anticipate requiring capacitor bank switching or fault interrupting should identify the breakers that must have capacitive current switching ratings on the equipment schedules and contract drawings used for the project Manufacturer’s standard medium voltage breakers meeting ANSI C37.xx are not all rated for switching capacitive loads Special breakers are usually available from vendors to comply with the ANSI C37.012 (Application Guide for Capacitor Current Switching) and other applicable ANSI standards The use of capacitive current rated breakers can affect the medium voltage switchgear layout, thus early identification of these capacitive loads are critical to the design process For example, the standard 15 kV Eaton 150 VCP-W 500, 1200 ampere vacuum breaker does not have a capacitive current switching rating, however the 15 kV Eaton 150 VCP-W 25C, 1200 ampere vacuum breaker does have the following general purpose ratings: ■ 25 ampere rms cable charging current switching ■ Isolated shunt capacitor bank switching current ratings of 25 to 600 amperes ■ Definite purpose back-to-back capacitor switch ratings required when two banks of capacitors are independently switched from the 15 kV switchgear bus The special breakers with these capacitive current ratings not have UL labels, thus UL assembly ratings are not available Contact Eaton for more details on vacuum breaker and fused load interrupter switch products with capacitive switching current ratings at medium voltages 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 37.0-4 Power Factor Capacitors & Harmonic Filters Application Considerations June 2006 Sheet 1626 Switching Devices 22 Table 37.0-2 Recommended Switching Devices ᕃ Capacitor Rating Amperes kvar Safety Switch Fuse Rating 23 Capacitor Rated Current Molded Case Breaker Trip Rating Table 37.0-2 (Continued) Power Breaker Trip Rating 240 Volts 24 2.5 7.5 Capacitor Rating Amperes kvar Safety Switch Fuse Rating Capacitor Rated Current Molded Case Breaker Trip Rating Power Breaker Trip Rating 600 Volts 6.0 12.0 18.0 15 20 30 15 20 30 15 20 30 7.5 10 4.8 7.2 9.6 15 15 20 15 15 15 15 15 15 25 10 15 20 24.1 36.1 48.1 40 60 80 40 70 90 40 50 70 15 20 25 14.4 19.2 24.1 25 35 40 30 30 40 20 30 40 26 25 30 45 60 72.2 108 100 125 200 100 125 175 90 100 150 30 35 40 28.9 33.6 38.5 50 60 70 50 50 70 40 50 70 27 50 60 75 120 144 180 200 250 300 200 225 275 175 200 250 45 50 60 43.3 48.1 57.8 80 80 100 70 100 100 70 70 90 28 90 100 120 217 240 289 400 400 500 350 400 500 300 350 400 75 80 100 72.2 77.0 96.2 125 150 175 125 125 150 100 125 150 29 125 135 150 301 325 361 500 600 600 500 500 600 450 500 500 120 125 150 115 120 144 200 200 250 175 200 225 175 175 200 30 180 200 225 433 480 541 800 800 900 700 800 900 600 700 800 160 180 200 154 173 192 300 300 350 250 300 300 225 250 300 31 240 250 270 578 602 650 1000 1000 1200 900 900 1000 800 900 1000 225 240 250 217 231 241 400 400 400 350 350 400 300 350 350 32 300 360 375 720 866 903 1200 1600 1500 — — — 1200 1200 1200 300 320 360 289 306 347 500 600 600 500 500 600 400 500 500 375 400 450 361 385 433 600 700 800 600 600 700 500 600 600 480 Volts 33 7.5 2.41 6.01 9.0 15 15 15 15 15 15 15 15 15 34 10 15 20 12.0 18.0 24.0 20 30 40 20 30 40 20 30 40 35 25 30 35 30.0 36.1 42 50 60 70 50 70 70 50 50 60 36 40 45 50 48.1 54 60.1 80 90 100 100 100 100 70 80 90 37 60 75 80 72.2 90.2 96.2 125 150 175 125 150 150 100 125 150 38 90 100 120 108 120 144 200 200 250 175 200 225 150 175 200 39 125 150 160 150 180 192 250 300 350 225 300 300 200 250 300 40 180 200 225 216 241 271 400 400 500 350 400 500 300 350 400 41 240 250 300 289 301 361 500 500 600 500 500 600 400 400 500 42 320 360 375 385 433 451 700 800 800 600 700 700 600 600 600 400 450 481 541 800 900 800 900 800 800 43 ᕃ Switching device ratings are based on percentage of capacitor-rated current as indicated (above) The interrupting rating of the switch must be selected to match the system fault current available at the point of capacitor application Whenever a capacitor bank is purchased with less than the ultimate kvar capacity of the rack or enclosure, the switch rating should be selected based on the ultimate kvar capacity — not the initial installed capacity For more information visit: www.EatonElectrical.com CA08104001E Power Factor Capacitors & Harmonic Filters Application Considerations June 2006 37.0-5 Sheet 1627 Capacitor Installation Installing Capacitors in a Plant Distribution System Location C — Line Side of Starter ■ ■ At the Load ■ Since capacitors act as kvar generators, the most efficient place to install them is directly at the motor, where kvar is consumed Three options exist for installing capacitors at the motor Use Figures 37.0-1 – 37.0-7, and the information below to determine which option is best for each motor ■ ■ Motors that are jogged, plugged, reversed Multi-speed motors Starters with open transition and starters that disconnect/reconnect capacitor during cycle Motors that start frequently Motor loads with high inertia, where disconnecting the motor with the capacitor can turn the motor into a self-excited generator Location A — Motor Side of Overload Relay At the Service Feeder ■ When correcting entire plant loads, capacitor banks can be installed at the service entrance, if load conditions and transformer size permits If the amount of correction is too large, some capacitors can be installed at individual motors or branch circuits New motor installations in which overloads can be sized in accordance with reduced current draw ■ Existing motors when no overload change is required Location B — Line Side of Overload Relay ■ Existing motors when overload rating surpasses code (see Appendix for NEC code requirements) Main Bus or Feeder 22 23 Fused Switch or Circuit Breaker ቢ 24 25 Capacitor Bank 26 Figure 37.0-2 Installing Capacitors Online ᕃ Refer to Pages 37.0-3 and 37.0-13 for switching device considerations and conductor sizing 27 28 29 When capacitors are connected to the bus, feeder, motor control center or switchboard, a disconnect and overcurrent protection must be provided 30 31 Locating Capacitors on Motor Circuits 32 Motor Feed C B Thermal Overload A 33 Motor 34 35 Fused Safety Switch or Breaker Motor Starter 36 37 38 Install at Location: Capacitor C Capacitor B Capacitor A 39 Figure 37.0-1 Locating Capacitors on Motor Circuits 40 41 42 43 CA08104001E For more information visit: www.EatonElectrical.com 37.0-6 Power Factor Capacitors & Harmonic Filters Application Considerations June 2006 Sheet 1628 Locating Capacitors 22 Locating Capacitors on Reduced Voltage and Multi-Speed Motors 23 24 25 Start: Close 6-7-2-3-4 Transfer: Open 6-7 Line Run: Close 1-5 4A Motor Stator B Wye Start: Close 1-2-3-7-8 Delta Run: Close 1-2-3-4-5-6 C 26 B A Motor Stator Line 27 Figure 37.0-3 Autotransformer — Closed Transition Note: Connect capacitor on motor side of starting contacts (2, 3, 4) at points A – B – C C 28 29 30 Start: Close 1-2-3 Second Step: Open 4-5-6 Third Step: Close 7-8-9 Figure 37.0-6 Wye-Delta Starting Note: Connect capacitor on motor side of starting contacts (1, 2, 3) at points A – B – C A Line B 31 32 Motor Stator C Start: Close 1-2-3 Run: Close 4-5-6 A B Note: Connect capacitor on motor side of starting contactor (1, 2, 3) at points A – B – C C A Line 38 Note: Connect capacitor on motor side of starting contactor (1, 2, 3) at points A – B – C C Motor Stator Start: Close 1-2-3 Run: Close 4-5-6 36 37 Figure 37.0-7 Reactor Starting B 35 Motor Stator 33 34 Line Figure 37.0-4 Series Resistance Starting Figure 37.0-5 Part-Winding Starting Note: Connect capacitor on motor side of starting contacts (1, 2, 3) at points A – B – C 39 40 41 42 43 For more information visit: www.EatonElectrical.com CA08104001E Power Factor Capacitors & Harmonic Filters Application Considerations June 2006 37.0-7 Sheet 1629 Harmonic Considerations Harmonic Considerations If 350 kvar of capacitors were used to improve power factor, h would be: A discussion of power system harmonics is incomplete without discussing the effects of power factor correction capacitors In an industrial plant containing power factor correction capacitors, harmonic currents and voltages can be magnified considerably due to the interaction of the capacitors with the service transformer This is referred to as harmonic resonance or parallel resonance For a typical plant containing power factor correction capacitors, the resonant frequency (frequency at which amplification occurs) normally falls in the vicinity of the 5th to the 13th harmonic Since non-linear loads typically inject currents at the 5th, 7th, 11th and 13th harmonics, a resonant or near-resonant condition will often result if drives and capacitors are installed on the same system, producing the symptoms and problems outlined in the previous section Note: Capacitors themselves not cause harmonics, but only aggravate potential harmonic problems Often, harmonic-related problems not “show up” until capacitors are applied for power factor correction It is a common misconception that the problem of applying capacitors in harmonic environments is limited to problems caused for the capacitor itself — that the capacitor’s lower impedance at higher frequencies causes a current overload into the capacitor and, therefore, must be removed However, the capacitor/harmonics problem must be viewed from a power system standpoint The capacitor-induced increase of harmonic voltages and currents on a plant’s system may be causing problems while the capacitor itself remains within its acceptable current rating Capacitor Banks and Transformers Can Cause Resonance Capacitors and transformers can create dangerous resonance conditions when capacitor banks are installed at the service entrance Under these conditions, harmonics produced by non-linear devices can be amplified many fold Problematic amplification of harmonics becomes more likely as more kvar is added to a system which contains a significant amount of non-linear load An estimate of the resonant harmonic frequency is found by using the following formula: kVA sys -kvar kVA sys = Short Circuit Capacity of the System kvar = Amount of Capacitor kvar on the Line h = The Harmonic Number referred to a 60 Hz Base h = 17,391 = 350 49.7 = 7.0 22 23 Because h falls right on the 7th harmonic, these capacitors could create a harmful resonance condition if non-linear devices were present in the factory In this case the capacitors should be applied only as harmonic filtering assemblies 24 Diagnosing a Potential Harmonics Related Problem 26 Negative symptoms of harmonics on plant equipment include blown fuses on capacitors, reduced motor life, false or spurious operations of fuses or circuit breakers, decreased life or increased noise in transformers or mis-operation of electronic or microprocessor controls If one or more of these symptoms occurs with regularity, then the following steps should be taken If the plant contains power factor correction capacitors, the current into the capacitors should be measured using a ‘true rms’ current meter If this value is higher than the capacitor’s rated current at the system voltage (by >5% or so), the presence of harmonic voltage distortion is likely 25 27 28 29 30 31 Conduct a paper audit of the plant’s harmonic-producing loads and system configuration This analysis starts with the gathering of kVA or horsepower data on all the major non-linear devices in the plant, all capacitors, and rating information on service entrance transformer(s) This data is analyzed to determine whether the conditions are present to create unfavorable levels of harmonics 32 If the electrical distribution system is complex — e.g., multiple service entrances, distributed capacitors — or if the paper audit is incomplete or considered to be too burdensome, the most definitive way to determine whether harmonics are causing a problem is through an on-site plant audit This audit involves an inspection of the electrical system layout and connected loads, as well as harmonic measurements taken at strategic locations This data can then be assembled and analyzed to obtain a clear and concise understanding of the power system 35 h = If h is near the values of the major harmonics generated by a non-linear device — i.e., 3, 5, 7, 11 — then the resonance circuit will greatly increase harmonic distortion For example, if a plant has a 1,500 kVA transformer with a 5-1/2% impedance and the short-circuit rating of the utility is 48,000 kVA, then kVAsys would equal 17,391 kVA 33 34 36 37 38 39 40 41 42 43 CA08104001E For more information visit: www.EatonElectrical.com 37.0-8 Power Factor Capacitors & Harmonic Filters Application Considerations June 2006 Sheet 1630 Harmonic Considerations 22 23 24 25 26 27 28 29 30 31 32 33 Eliminating Harmonic Problems When power factor correction is required in the presence of non-linear loads, or the amount of harmonic distortion must be reduced to solve power quality problems or avoid penalties, the most reliable, lowest cost solution is often realized with the use of harmonic filters Passive and Switched Harmonic Filters A shunt harmonic filter (see Figure 37.0-8) is, essentially, a power factor correction capacitor combined with a series iron core reactor A filter provides power factor correction at the fundamental frequency and becomes an inductance (like a motor) at frequencies higher than its “tuning point.” Most harmonic filters are tuned below the 5th harmonic Therefore, the filter provides an inductive impedance path to those currents at harmonic frequencies created by nearly all three-phase non-linear loads (5th, 7th, 11th, 13th, etc.) Since the filter is not capacitive at these frequencies, the plant electrical system can no longer resonate at these frequencies and can not magnify the harmonic voltages and currents A shunt harmonic filter therefore accomplishes three things: Provides power factor correction Prevents harmonic overvoltages due to resonance Reduces voltage harmonic distortion and transformer harmonic loading at frequencies above its tuning point In some circumstances, a harmonic resonance condition may accrue gradually over time as capacitors and non-linear loads are installed in a plant The replacement of such capacitors with harmonic filters in order to correct a problem may be prohibitively expensive Custom-designed harmonic filters which are able to eliminate problems associated with resonance at any particular frequency while providing an extremely low amount of power factor correction capacitance These low kvar filters are therefore able to provide the same amount of filtering capacity as a much larger conventional filter, but at a lower cost Phase A B C Reactor Capacitor Bank Figure 37.0-8 Shunt Harmonic Filter If the plant loads vary widely then a switched capacitor/filter bank is recommended 34 35 36 37 38 39 40 41 42 43 For more information visit: www.EatonElectrical.com CA08104001E June 2006 Power Factor Capacitors & Harmonic Filters Application Considerations 37.0-9 Sheet 1631 Motor Power Factor Correction Motor Power Factor Correction Tables 37.0-3 and 37.0-4 contain suggested maximum capacitor ratings for induction motors switched with the capacitor The data is general in nature and representative of general purpose induction motors of standard design The preferable means to select capacitor ratings is based on the “maximum recommended kvar” information available from the motor manufacturer If this is not possible or feasible, the tables can be used An important point to remember is that if the capacitor used with the motor is too large, self-excitation may cause a motor-damaging overvoltage when the motor and capacitor combination is disconnected from the line In addition, high transient torques capable of damaging the motor shaft or coupling can occur if the motor is reconnected to the line while rotating and still generating a voltage of self-excitation Definitions kvar — rating of the capacitor in reactive kilovolt-amperes This value is approximately equal to the motor no-load magnetizing kilovars % AR — percent reduction in line current due to the capacitor A capacitor located on the motor side of the overload relay reduces line current through the relay Therefore, a different overload relay and/or setting may be necessary The reduction in line current may be determined by measuring line current with and without the capacitor or by calculation as follows: To derate a capacitor used on a system voltage lower than the capacitor voltage rating, such as a 240-volt capacitor used on a 208-volt system, use the following formula: ( Applied Voltage ) Nameplate kvar × ( Nameplate Voltage ) (Original PF) % AR = 100 – 100 × −−−−−−−−−−−−−−−−−−−−−−− (Improved PF) If a capacitor is used with a lower kvar rating than listed in tables, the % AR can be calculated as follows: kVAC = KW (tan phase1 – tan phase2) The tables can also be used for other motor ratings as follows: A For standard 60 Hz motors operating at 50 Hz: kvar = 1.7 – 1.4 of kvar listed % AR = 1.8 – 1.35 of % AR listed B For standard 50 Hz motors operating at 50 Hz: kvar = 1.4 – 1.1 of kvar listed % AR = 1.4 – 1.05 of % AR listed C For standard 60 Hz wound-rotor motors: kvar = 1.1 of kvar listed % AR= 1.05 of % AR listed Note: For A, B, C, the larger multipliers apply for motors of higher speeds; i.e., 3600 rpm = 1.7 mult., 1800 rpm = 1.65 mult., etc 23 Actual kvar = For the kVAC required to correct the power factor from a given value of COS φ1 to COS φ2, the formula is: Actual kvar % AR = Listed % AR × −−−−−−−−−−−−−−−−−−−−−− kvar in Table 22 Capacitors cause a voltage rise At light load periods the capacitive voltage rise can raise the voltage at the location of the capacitors to an unacceptable level This voltage rise can be calculated approximately by the formula MVA r % VR = −−−−−−−−−−− − MVA SC 24 25 26 27 28 29 30 31 MVAR is the capacitor rating and MVASC is the system short circuit capacity With the introduction of variable speed drives and other harmonic current generating loads, the capacitor impedance value determined must not be resonant with the inductive reactances of the system This matter is discussed further under the heading “Harmonics and Non-Linear Loads.” 32 33 34 35 36 37 38 39 40 41 42 43 CA08104001E For more information visit: www.EatonElectrical.com 37.0-10 Power Factor Capacitors & Harmonic Filters Application Considerations June 2006 Sheet 1632 Application Considerations — Motors 22 23 24 Table 37.0-3 Suggested Maximum Capacitor Ratings Induction Motor hp Rating 7.5 31 — 1800 RPM Current Capacitor Reduction kvar % — 1200 RPM Current Capacitor Reduction kvar % — 900 RPM 10 — 720 RPM 12 — 600 RPM Current Capacitor Reduction kvar % Current Capacitor Reduction kvar % Current Capacitor Reduction kvar % Current Reduction % 14 12 11 1.5 2.5 15 13 12 1.5 20 17 15 27 25 22 2.5 35 32 30 41 37 34 10 15 20 10 9 11 10 10 14 13 12 7.5 21 18 16 27 23 21 7.5 12.5 31 27 25 25 30 40 9 8 10 9 7.5 10 11 11 10 10 12.5 15 14 13 10 12.5 15 20 18 16 15 17.5 20 23 22 20 50 60 75 12.5 15 17.5 8 10 15 17.5 8 12.5 15 17.5 10 10 10 15 17.5 20 12 11 10 20 22.5 25 15 15 14 25 27.5 35 19 19 18 100 125 150 22.5 27.5 30 8 20 25 30 8 25 30 35 9 27.5 30 37.5 10 10 10 35 40 50 13 13 12 40 50 50 17 16 15 200 250 300 40 50 60 8 37.5 45 50 7 40 50 60 8 50 60 60 10 9 60 70 80 12 11 11 60 75 90 14 13 12 350 400 450 500 60 75 75 75 8 8 60 60 75 75 6 75 75 80 85 8 8 75 85 90 100 9 9 90 95 100 100 10 10 9 95 100 110 120 11 11 11 10 27 30 Capacitor kvar 1.5 2.5 26 29 — 3600 RPM Used for High Efficiency Motors and Older Design (Pre “T-Frame”) Motors ᕃ 25 28 Number of Poles and Nominal Motor Speed in RPM T-Frame NEMAா “Design B” Motors ᕃ 32 1.5 14 14 14 1.5 2.5 24 23 22 1.5 30 28 26 42 38 31 40 40 40 50 49 49 33 7.5 10 15 2.5 14 14 12 20 18 18 21 21 20 7.5 28 27 24 7.5 38 36 32 10 45 38 34 34 20 25 30 7.5 12 12 11 7.5 17 17 16 7.5 10 19 19 19 10 15 23 23 22 10 12.5 15 29 25 24 12.5 17.5 20 30 30 30 35 40 50 60 12.5 15 17.5 12 12 12 15 17.5 20 16 15 15 15 20 22.5 19 19 17 17.5 22.5 25 21 21 20 20 22.5 30 24 24 22 25 30 35 30 30 28 36 75 100 125 20 22.5 25 12 11 10 25 30 35 14 14 12 25 30 35 15 12 12 30 35 40 17 16 14 35 40 45 21 15 15 40 45 50 19 17 17 37 150 200 250 30 35 40 10 10 11 40 50 60 12 11 10 40 50 60 12 11 10 50 70 80 14 14 13 50 70 90 13 13 13 60 90 100 17 17 17 38 300 350 400 45 50 75 11 12 10 70 75 80 10 8 75 90 100 12 12 12 100 120 130 14 13 13 100 120 140 13 13 13 120 135 150 17 15 15 450 500 80 100 8 90 120 120 150 10 12 140 160 12 12 160 180 14 13 160 180 15 15 39 ᕃ For use with 3-phase, 60 Hz NEMA Classification B Motors to raise full load power factor to approximately 95% 40 41 42 43 For more information visit: www.EatonElectrical.com CA08104001E 37.5-2 Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage June 2006 Sheet 1660 Technical Data 22 Technical Data Table 37.5-1 UNIVAR Three-Phase Ratings 23 24 25 26 Volts Hertz kvar 2400 60 25 – 825 4160 60 25 – 900 4800 60 25 – 900 6600 50/60 25 – 400 7200 50/60 25 – 400 12,470 60 50 – 500 13,800 60 50 – 500 Table 37.5-2 UNIVAR Dimensions — Standard Fuses (2400 — 4800 Volts) 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 Description kvar 2400 Volt 4160 Volt 4800 Volt Dimensions (A) Inches (mm) Dimensions (B) Inches (mm) Approx Weight Lbs (kg) Figure No ᕃ Standard dwg no ᕃ 25 25243FKED 25413FKED 25483FKED 24.44 (621) 50 50243FKED 50413FKED 50483FKED 26.06 (662) 3.71 (94) 54 (25) 37.5-1 5D10237 5.34 (136) 59 (27) 37.5-1 75 75243FKED 75413FKED 75483FKED 5D10237 27.68 (703) 6.96 (177) 64 (29) 37.5-1 100 100243FKED 100413FKED 5D10237 100483FKED 29.44 (748) 8.71 (221) 69 (31) 37.5-1 125 125243FKED 5D10237 125413FKED 125483FKED 30.18 (767) 9.46 (240) 76 (35) 37.5-1 150 5D10237 150243FKED 150413FKED 150483FKED 32.68 (830) 11.96 (304) 81 (37) 37.5-1 5D10237 175 175243FKED 175413FKED 175483FKED 33.35 (847) 12.63 (321) 86 (39) 37.5-1 5D10237 200 200243FKED 200413FKED 200483FKED 33.35 (847) 12.63 (321) 92 (42) 37.5-1 5D10237 225 225FKY2432 225FKY4132 225FKY4832 36.06 (916) 18.33 (466) 103 (47) 37.5-1 5D10237 250 250FKY2432 250FKY4132 250FKY4832 36.06 (916) 18.33 (466) 103 (47) 37.5-1 5D10237 275 276FKY2432 275FKY4132 275FKY4832 36.06 (992) 18.33 (466) 114 (52) 37.5-1 5D10237 300 — 300FKY4132 300FKY4832 36.06 (992) 18.33 (466) 114 (52) 37.5-1 5D10237 300 300FKY2432 — — 33.43 (849) 12.70 (323) 149 (68) 37.5-2 5D10239 325 325FKY2432 325FKY4132 325FKY4832 33.43 (849) 12.70 (323) 154 (70) 37.5-2 5D10239 350 350FKY2432 350FKY4132 350FKY4832 33.43 (849) 12.70 (323) 159 (72) 37.5-2 5D10239 375 375FKY2432 375FKY4132 375FKY4832 33.43 (849) 12.70 (323) 165 (75) 37.5-2 5D10239 400 400FKY2432 400FKY4132 400FKY4832 33.43 (849) 12.70 (323) 171 (78) 37.5-2 5D10239 425 425FKY2433 425FKY4133 425FKY4833 39.18 (995) 18.45 (469) 181 (82) 37.5-2 5D10239 450 450FKY2433 450FKY4133 450FKY4833 39.18 (995) 18.45 (469) 192 (87) 37.5-2 5D10239 500 500FKY2433 500FKY4133 500FKY4833 39.18 (995) 18.45 (469) 192 (87) 37.5-2 5D10239 525 525FKY2433 525FKY4133 525FKY4833 39.18 (995) 18.45 (469) 203 (92) 37.5-2 5D10239 550 550FKY2433 550FKY4133 550FKY4833 39.18 (995) 18.45 (469) 214 (97) 37.5-2 5D10239 575 — 575FKY4133 575FKY4833 39.18 (995) 18.45 (469) 214 (97) 37.5-2 5D10239 600 — 600FKY4133 600FKY4833 39.18 (995) 18.45 (469) 214 (97) 37.5-2 5D10239 575 575FKY2433 — — 33.43 (849) 12.70 (323) 248 (113) 37.5-3 5D10241 600 600FKY2433 — — 33.43 (849) 12.70 (323) 254 (115) 37.5-3 5D10241 625 625FKY2433 625FKY4133 625FKY4833 39.18 (995) 18.45 (469) 265 (120) 37.5-3 5D10241 650 650FKY2433 650FKY4133 650FKY4833 39.18 (995) 18.45 (469) 276 (125) 37.5-3 5D10241 675 675FKY2433 675FKY4133 675FKY4833 39.18 (995) 18.45 (469) 287 (130) 37.5-3 5D10241 700 700FKY2433 700FKY4133 700FKY4833 39.18 (995) 18.45 (469) 298 (130) 37.5-3 5D10241 725 725FKY2433 725FKY4133 725FKY4833 39.18 (995) 18.45 (469) 298 (130) 37.5-3 5D10241 750 750FKY2433 750FKY4133 750FKY4833 39.18 (995) 18.45 (469) 298 (130) 37.5-3 5D10241 775 775FKY2433 775FKY4133 775FKY4833 39.18 (995) 18.45 (469) 309 (135) 37.5-3 5D10241 800 800FKY2433 800FKY4133 800FKY4833 39.18 (995) 18.45 (469) 320 (140) 37.5-3 5D10241 825 825FKY2433 825FKY4133 825FKY4833 39.18 (995) 18.45 (469) 331 (145) 37.5-3 5D10241 850 — 850FKY4133 850FKY4833 39.18 (995) 18.45 (469) 331 (145) 37.5-3 5D10241 875 — 875FKY4133 875FKY4833 39.18 (995) 18.45 (469) 331 (145) 37.5-3 5D10241 900 — 900FKY4133 900FKY4833 39.18 (995) 18.45 (469) 331 (1450 37.5-3 5D10241 ᕃ See Page 37.5-3 for figure and drawing details For more information visit: www.EatonElectrical.com CA08104001E Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage June 2006 37.5-3 Sheet 1661 Dimensions Dimensions — Medium Voltage UNIVAR Fixed Capacitors Solderless Conn for #10 Solid to #4 Str'd Cond Removable Top Cover 11.34 22 Removable Top Cover Terminal for #6 to 250 kcmil Cable 26.75 21.08 21.08 NP Solderless Conn for #10 Solid to #2 Str'd Cond .25-20 Grd Scr .25-20 Grd Scr A 26 (4).562 (2).500 x 625 Slots B 4.50 24.50 15.62 16.58 Figure 37.5-3 Drawing No 5D10241 Figure 37.5-1 Drawing No 5D10237 27 15.75 17.15 28 29 30 Terminal for #14 to 1/0 Cable 19.75 B Holes 14.50 17 24 25 A Removable Top Cover 23 21.08 25-20 Grd Scr 31 32 A 33 (4).562 Mounting Holes 14.50 17.50 B 15.75 17.15 34 35 36 Figure 37.5-2 Drawing No 5D10239 37 38 39 40 41 42 43 CA08104001E For more information visit: www.EatonElectrical.com 37.5-4 Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage June 2006 Sheet 1662 Dimensions 22 Table 37.5-3 UNIVAR Dimensions —Optional Fuses (2400 – 4800 Volts) Description 4160 Volt 4800 Volt Dimensions (A) Inches (mm) Dimensions (B) Inches (mm) Approx Weight 2400 Volt Lbs (kg) Figure No Standard Dwg No 25 50 75 25243FKED3 50243FKED3 75243FKED3 25413FKED3 50413FKED3 75413FKED3 25483FKED3 50483FKED3 75483FKED3 27.68 (703) 27.68 (703) 27.68 (703) 6.69 (177) 6.96 (177) 6.96 (177) 64 (29) 64 (29) 64 (29) 37.5-4 37.5-4 37.5-4 5D10238 5D10238 5D10238 100 125 150 100243FKED3 125243FKED3 150243FKED3 100413FKED3 125413FKED3 150413FKED3 100483FKED3 125483FKED3 150483FKED3 29.44 (748) 30.18 (767) 32.68 (830) 8.71 (221) 9.46 (240) 11.96 (304) 69 (31) 76 (35) 81 (37) 37.5-4 37.5-4 37.5-4 5D10238 5D10238 5D10238 25 175 200 225 175243FKED3 200243FKED3 225FKY24323 175413FKED3 200413FKED3 225FKY41323 175483FKED3 200483FKED3 225FKY48323 33.35 (847) 33.35 (847) 36.06 (916) 12.63 (321) 12.63 (321) 18.33 (466) 86 (39) 92 (42) 103 (47) 37.5-4 37.5-4 37.5-4 5D10238 5D10238 5D10238 26 250 275 300 250FKY24323 276FKY24323 — 250FKY41323 275FKY41323 300FKY41323 250FKY48323 275FKY48323 300FKY48323 36.06 (916) 36.06 (992) 39.06 (992) 18.33 (466) 18.33 (466) 18.33 (466) 103 (47) 114 (52) 114 (52) 37.5-4 37.5-4 37.5-4 5D10238 5D10238 5D10238 27 300 325 350 300FKY24323 325FKY24323 350FKY24323 — 325FKY41323 350FKY41323 — 325FKY48323 350FKY4832 33.43 (849) 33.43 (849) 33.43 (849) 12.70 (323) 12.70 (323) 12.70 (323) 149 (68) 154 (70) 159 (72) 37.5-5 37.5-5 37.5-5 5D10240 5D10240 5D10240 28 375 400 425 375FKY24323 400FKY24323 425FKY24333 375FKY41323 400FKY41323 425FKY41333 375FKY48323 400FKY48323 425FKY48333 33.43 (849) 33.43 (849) 39.18 (995) 12.70 (323) 12.70 (323) 18.45 (469) 165 (75) 171 (78) 181 (82) 37.5-5 37.5-5 37.5-5 5D10240 5D10240 5D10240 29 450 500 525 450FKY24333 500FKY24333 525FKY24333 450FKY41333 500FKY41333 525FKY41333 450FKY48333 500FKY48333 525FKY48333 39.18 (995) 39.18 (995) 39.18 (995) 18.45 (469) 18.45 (469) 18.45 (469) 192 (87) 192 (87) 203 (92) 37.5-5 37.5-5 37.5-5 5D10240 5D10240 5D10240 30 550 575 600 550FKY24333 — — 550FKY41333 575FKY41333 600FKY41333 550FKY48333 575FKY48333 600FKY48333 39.18 (995) 39.18 (995) 39.18 (995) 18.45 (469) 18.45 (469) 18.45 (469) 214 (97) 214 (97) 214 (97) 37.5-5 37.5-5 37.5-5 5D10240 5D10240 5D10240 31 575 600 625 575FKY24333 600FKY24333 625FKY24333 — — 625FKY41333 — — 625FKY48333 33.43 (849) 33.43 (849) 39.18 (995) 12.70 (323) 12.70 (323) 18.45 (469) 248 (113) 254 (115) 265 (120) 37.5-6 37.5-6 37.5-6 5D10242 5D10242 5D10242 32 650 675 700 650FKY24333 675FKY24333 700FKY24333 650FKY41333 675FKY41333 700FKY41333 650FKY48333 675FKY48333 700FKY48333 39.18 (995) 39.18 (995) 39.18 (995) 18.45 (469) 18.45 (469) 18.45 (469) 276 (125) 287 (130) 298 (130) 37.5-6 37.5-6 37.5-6 5D10242 5D10242 5D10242 33 725 750 775 800 725FKY24333 750FKY42333 775FKY24333 800FKY24333 725FKY41333 750FKY41333 775FKY41333 800FKY41333 725FKY48333 750FKY48333 775FKY48333 800FKY48333 39.18 (995) 39.18 (995) 39.18 (995) 39.18 (995) 18.45 (469) 18.45 (469) 18.45 (469) 18.45 (469) 298 (130) 298 (130) 309 (135) 320 (140) 37.5-6 37.5-6 37.5-6 37.5-6 5D10242 5D10242 5D10242 5D10242 825 850 875 900 — — — — 825FKY41333 850FKY41333 875FKY41333 900FKY41333 825FKY48333 850FKY48333 875FKY48333 900FKY48333 39.18 (995) 39.18 (995) 39.18 (995) 39.18 (995) 18.45 (469) 18.45 (469) 18.45 (469) 18.45 (469) 331 (145) 331 (145) 331 (145) 331 (145) 37.5-6 37.5-6 37.5-6 37.5-6 5D10242 5D10242 5D10242 5D10242 kvar 23 24 34 35 Table 37.5-4 UNIVAR Dimensions — Standard Fuses (6600 – 13,800 Volts) 36 37 38 39 40 Standard Fuses Dimensions 7200 Volt 13,800 Volt 50 100 150 50663FKED3 50723FKED3 50123FKED3 50133FKED3 4.25 (108) 45.50 (1156) 100663FKED3 100723FKED3 100123FKED3 100133FKED3 4.25 (108) 45.50 (1156) 150663FKED3 150723FKED3 150123FKED3 150133FKED3 4.25 (108) 45.50 (1156) 14.46 (367) 0.25 (6) 198 (90) 14.46 (367) 0.25 (6) 198 (90) 14.46 (367) 0.25 (6) 198 (90) 37.5-7 37.5-7 37.5-7 5D10243 5D10243 5D10243 200 250 300 200663FKED3 200723FKED3 200123FKED3 200133FKED3 5.62 (143) 45.50 (1156) 250FKY66323 250FKY2323 250FKY12323 250FKY13323 5.62 (143) 48.50 (1232) 300FKY66323 300FKY2323 300FKY12323 300FKY13323 5.62 (143) 53.50 (1359) 14.46 (367) 0.25 (6) 220 (100) 17.46 (443) 0.25 (6) 246 (112) 17.46 (443) 0.25 (6) 246 (112) 37.5-7 37.5-7 37.5-7 5D10243 5D10243 5D10243 350 400 450 500 350FKY66323 400FKY66323 — — 17.46 (443) 22.46 (570) 22.46 (570) 26.21 (666) 37.5-7 37.5-7 37.5-7 37.5-7 5D10243 5D10243 5D10243 5D10243 350FKY12323 400FKY12323 450FKY12323 500FKY12323 350FKY13323 400FKY13323 450FKY13323 500FKY13323 (A) Inches (mm) Figure Standard No Dwg No 6600 Volt 350FKY2323 400FKY2323 — — 12,470 Volt Approx Weight kvar 5.62 (143) 5.62 (143) 5.62 (143) 5.62 (143) (B) Inches (mm) 53.50 (1359) 57.25 (1454) 57.25 (1454) 57.25 (1454) (C) Inches (mm) (D) Inches (mm) 0.25 (6) 0.25 (6) 0.25 (6) 0.25 (6) Lbs (kg) 246 (112) 281 (128) 281 (128) 336 (153) 41 42 43 For more information visit: www.EatonElectrical.com CA08104001E Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage June 2006 37.5-5 Sheet 1663 Dimensions Dimensions — Medium Voltage UNIVAR Fixed Capacitors Removable Top Cover Solderless Conn for #10 Solid to #4 Str'd Cond Removable Top Cover 11.34 22 26.75 23 21.08 25-20 Grd Scr NP 21.08 25-20 Grd Scr 24 25 A A 26 B (2).500 x 625 Slots B 27 14.50 15.75 24.50 17.15 (4).562 Mounting Holes 15.62 16.58 4.00 Figure 37.5-4 Drawing No 5D10238 Removable Top Cover 19.75 29 Figure 37.5-6 Drawing No 5D10242 Removable Top Cover 21.08 250-20 Grd Scr Barriers Solderless Conn for A #10 Solid to A #4 Str'd Conn Grd Scr 31 32 33 B (4).562 Mounting Holes 30 34.00 16.42 25-20 A 28 B 34 D C (2).500 x 625 Slots [13 x 16] 14.50 17.50 Figure 37.5-5 Drawing No 5D10240 15.75 17.15 A 24.12 25.08 Figure 37.5-7 Drawing No 5D10243 35 36 37 38 39 40 41 42 43 CA08104001E For more information visit: www.EatonElectrical.com 37.5-6 Power Factor Capacitors and Harmonic Filters June 2006 Sheet 1664 22 This page intentionally left blank 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 For more information visit: www.EatonElectrical.com CA08104001E June 2006 Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage 37.6-1 Sheet 1665 General Description AUTOVAR Medium Voltage Metal-Enclosed PFC System Product Description The AUTOVAR medium voltage automatic power factor capacitor systems are designed for power factor correction in applications where plant power factor can be constant or changing, and an engineered solution is required These systems can be a fixed amount of capacitance with a disconnect, a number of switched capacitance stages, or a combination of both The AUTOVAR medium voltage capacitor system can switch stages of capacitance in and out automatically based on information collected by the power factor controller on the door-in-door control panel Applications ■ Large motors ■ Motor control centers ■ Branch circuits ■ Service entrance Utility Customers Metal-enclosed power factor correction systems are fully assembled, tested and ready for installation Very little field assembly is required Installation and maintenance costs for metalenclosed systems are low compared to pole and rack mounted capacitor banks Metal-enclosed systems and harmonic filters are less vulnerable to wildlife and airborne contaminants that can cause tracking and faults In addition, metalenclosed systems significantly reduce the risks and the associated liability involving untrained personnel All live parts are contained in a grounded, key interlocked enclosure and no internal hardware is accessible Metal-enclosed systems are aesthetically pleasing due to their low profile, and can be painted to match the surrounding architecture These are just some of the reasons more and more utilities are utilizing metal-enclosed capacitor and harmonic filter systems CA08104001E Industrial Customers Large industrial power users can utilize the benefits associated with medium voltage power factor correction and harmonic filtering Medium voltage solutions usually support the scale and scope of larger services Medium voltage applications can be found in the following types of industries as examples: automotives, pulp and paper, plastics, petrochemical, and heavy manufacturing Individual fixed capacitors provide power factor correction directly at the cause of the problem, such as a large horsepower MV motor Medium voltage systems allow large industrials to correct power factor at or close to the point of common coupling (PCC), where the utility electrical system meets theirs This allows correction for an entire facility, instead of having to correct at multiple locations The Cutler-Hammer NEMA 3R design also allows the system to be placed outdoors, saving valuable manufacturing floor space The savings can be enormous, in materials, installation costs and floor space In short, medium voltage solutions provide a cost-effective alternative to many local low voltage power factor correction units, while protecting the customer’s entire electrical distribution system Commercial Customers Many commercial customers are purchasing power from their utility at higher voltages today (2.4 kV – 15 kV), and can also take advantage of medium voltage power factor correction systems These solutions can meet the needs of large office complexes, hospitals and universities, among others The benefits of safety (key interlocking, no exposed live parts, etc.), and aesthetics (low profile, can be painted to match environment) both meet the needs of these applications where there are large numbers of untrained personnel in proximity of electrical equipment Features, Benefits and Functions 22 Benefits 23 Ease of Installation 24 Eaton makes installation easy All systems are completely assembled in the factory, with all equipment pre-wired and pre-tested for easy on-site installation Only shipping splits must be connected in the field Splice kits connect bus systems, and control wiring is easily connected at each enclosure Current limiting fuses, contactor assemblies, and the incoming switch assembly can be removed from the enclosure if needed Line terminals are completely accessible from the front of the system Personnel Safety Positive mechanical isolating switch with visible disconnect completely grounds and isolates the unit from the line connectors A screened barrier protects personnel from live parts All medium voltage doors are mechanically interlocked with the disconnect switch Key interlocks are provided standard on all enclosure doors, and can be coordinated with upstream disconnect devices The low voltage control section has a separate doorin-door design, and is segregated from the medium voltage sections so that an operator can work in that section safely Ease of Maintenance All components are front-accessible, facilitating routine inspection or parts replacement A viewing window is standard on all compartment doors 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 For more information visit: www.EatonElectrical.com 37.6-2 Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage June 2006 Sheet 1666 General Description 22 23 24 25 Flexibility Systems are expandable The customer can add stages in the future by connecting the phase bus in the field via splice kits Structures can be bolted together in the field ■ ■ ■ 26 27 ■ ■ ■ 28 29 ■ ■ 30 ■ ■ ■ 31 ■ 32 ■ ■ ■ 33 ■ ■ 34 35 ■ ■ ■ ■ ■ 36 Voltages from 2400 V – 34.5 kV Reactive power ratings through 30 MVar Harmonic tuned, de-tuned, or multi-tuned filter designs available Externally fused capacitor units standard Blown fuse indication standard Integral load interrupter switch, NEMA hole termination pad, or VCP-TLC draw-out type circuit breaker Delivered fully assembled, tested and ready for interconnection Integral protection and control system Top or bottom cable entry Earthing switch 60 kV BIL up to 4.8 kV 95 kV BIL from 4.8 kV to 14.4 kV 125 kV BIL from 14.4 kV to 27 kV 170 kV BIL above 27 kV Up to 12 automatic switched capacitor stages Warning labels Meets the following requirements: ANSI IEEE NEC NESC Main incoming fuses are rated 63 kAIC to provide main bus protection, as well as back-up protection for the capacitor systems Standard Features — AUTOVAR MV Enclosure Free-standing, 11-gauge steel construction with 3-point padlockable latching handles and stainless steel hinges The enclosure is painted with a corrosion-resistant ANSI 61 light gray enamel paint as standard Other colors are available as an option NEMA 3R construction is standard, NEMA 4X is available as an option Load Interrupter Air Disconnect Switch Integral disconnect switch, externally operated, mechanically chain driven with visible blades is available as per NEC requirements Disconnect switch is mechanically interlocked with the ground switch, and with the customer’s upstream device (if applicable) Incoming section is frontaccessible only for safety, and screens isolate live connections from the user Enclosure is UL/CSA approved See Figure 37.6-2 for dimensions and elevations See Figure 37.6-1 for a typical singleline drawing Medium Voltage PFC Enclosure Incoming Section with Protective Screens 37 38 39 Bottom Plate Incoming Cutout Provided Standard 40 41 Incoming Section with Screens Removed 42 43 For more information visit: www.EatonElectrical.com CA08104001E June 2006 Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage 37.6-3 Sheet 1667 General Description Ground Switch Vacuum Contactors Individual Capacitor Fusing A ground switch is provided to ground the load-side terminals of the incoming switch (or MLO) for safety during maintenance Optional controls are available to permit closing contactors after the grounding switch has been closed to ground capacitors immediately (rather than waiting five (5) minutes for full discharge) On multi-stage capacitor systems, each stage is controlled by low maintenance vacuum contactors (2.4 – 7.2 kV) or vacuum switches (7.2 – 15 kV) depending on the application (see below) Oil switches are also available Each capacitor is externally fused with current limiting fuses Fuses are equipped with blown fuse indication Internally fused capacitors are also available as an option 22 23 24 25 26 27 28 29 Ground Switch in the Incoming Section 30 Vacuum Switches On multi-stage capacitor systems, each stage is controlled by low maintenance vacuum contactors (2.4 – 7.2 kV) or vacuum switches (7.2 – 15 kV) depending on the application (see below) Oil switches are also available 31 Each Capacitor Section is Individually Fused Environmental Controls kV Switched Capacitor Stage Enclosure ■ Exhaust fans: Exhaust fans are provided for forced air ventilation of all enclosures as standard ■ Thermal controls: Thermostats are included as standard to help maintain an acceptable internal environment for all components ■ Space heaters: Space heaters are provided to control moisture and humidity inside all enclosures 32 33 34 35 36 37 38 39 40 41 15 kV Switched Capacitor Stage Enclosure 42 43 CA08104001E For more information visit: www.EatonElectrical.com 37.6-4 Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage June 2006 Sheet 1668 General Description 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Capacitors Key Interlock System Control Panel Low loss, double-bushing capacitors that meet or exceed IEC 871, IEEE Std 18 and CSA standards are supplied Capacitors are connected in an ungrounded wye as standard, but can be connected delta as well The dielectric fluid is environmentally friendly, biodegradable, non-PCB Capacitor units are equipped with internal discharge resistors which reduce the residual voltage to less than 50 volts within minutes of de-energization The key interlock system controls the sequential operation of the load break switch (or circuit breaker) and the ground switch to permit safe entry into the capacitor system All capacitor stage enclosures are also interlocked with the ground switch If applicable, the customer’s upstream disconnect device can be interlocked as well See Figure 37.6-1 for key interlock operation on a typical single-line drawing A door-in-door NEMA 3R swing-out control panel is provided on the main incoming structure as standard This unit includes a viewing window so that all controls and information can be viewed without opening the panel All low voltage controls and logic are accessible from the front of the system, and are isolated from the medium voltage section ■ PFC controller Ammeter with switch (for maintenance and diagnostic purposes) ■ Stage ON/OFF pilot lights ■ Manual stage operation switches ■ Any special controls requested by the customer ■ Harmonic Filtering Eaton’s Cutler-Hammer medium voltage harmonic filter systems are designed for industrial, utility and commercial power systems to improve power factor, reduce harmonic distortion, increase system capacity and reduce I2R losses The reactors are typically tuned to the 4.7th harmonic, to mitigate the most damaging 5th level harmonic This is the most common harmonic produced by six pulse variable speed drives These filters are designed to the unique specifications of each electrical distribution system Medium voltage capacitor banks can also be configured with de-tuned harmonic filters, typically set to the 4.2nd harmonic This helps avoid harmonic resonance problems, provides harmonic filtering, and avoids the overloading that is possible with an improperly applied filter 36 Included: Key Interlock System Ensures Safety in Main and Stage Doors Blown Fuse Detection System A visual pop-up blown fuse detection system is provided as standard Control Power Transformer A fused control power transformer rated for 1.75 kVA is provided for protection, control and operation of the capacitor or harmonic filter system Door-in-Door Control Panel Transient Voltage Surge Suppression 37 A TVSS unit is supplied standard for protection of all low voltage controls in the system 38 39 40 41 42 CPT and TVSS Provide Power and Protection for Control Section 43 Harmonic Filter Capacitor Stage Enclosure For more information visit: www.EatonElectrical.com CA08104001E Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage June 2006 37.6-5 Sheet 1669 General Description Solid-State Controller 22 Automatic metal-enclosed capacitors and harmonic filter systems come equipped with an automatic controller that switches each capacitor stage based upon power factor The customer simply programs in the target PF to meet The controller analyzes current PF, the size of each stage, and turns on and off stages to meet the customer’s programmed target The controller has alarms such as power factor out of range, high harmonic voltage content and loss of power 23 24 25 26 27 Up to 12 steps of capacitance can be designed into any system Customers can note this feature when designing for future expansions 28 Communications Communications of power factor data via RS-232, RS-485 or Modbusா is available as an option Communicated information from the controllers: ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Voltage Current Target power factor Current power factor Active power Apparent power Reactive power Number of steps in the circuit All alarm status All counters Time and date Continuous Ground Bus with Pad in Each Section Inrush Reactor for Back-to-Back Switching Bus ■ Continuous 1/4” x 2” silver-plated copper bus rated 600 A standard is provided throughout the line-up for easy interconnection, field installation and future expansion ■ ■ ■ ■ Inrush Reactors Inrush reactors are provided as standard on all switched (non-harmonic filtered) capacitor systems for protection against transients from backto-back switching Reactors in harmonic filtered applications provide this same protection Additional Standard Controls and Features ■ Phase Bus Continuous 1/4” x 1” silver-plated copper ground bus rated 300 A is provided throughout the line-up for easy interconnection, field installation and future expansion Ground studs are available in all structures for customer connection Three-phase manual current monitoring, for maintenance purposes Unbalance alarm and unit shutdown on all wye-connected systems Unit alarm and isolated fail-safe contacts for customer use on all systems Controls allow sufficient time (5 minutes) to allow the capacitors time to discharge before re-energization can occur Overvoltage alarm Temperature alarms on all harmonic filter units Manual stage controls 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 CA08104001E For more information visit: www.EatonElectrical.com 37.6-6 Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage June 2006 Sheet 1670 General Description Lightning Arresters 22 Optional heavy-duty distribution class lightning arresters protect the capacitor system from lightning and switching transients 23 IQ Digital Power Meter 24 25 Medium Voltage Metal-Enclosed PFC System 26 27 Optional Features Fixed Capacitor Systems 28 29 30 A highly advanced digital power meter (IQ Analyzer or Power Xpertீ series), suited to many power and control applications, can be supplied as an option This solid-state meter can take the place of numerous meters and control circuits to meet your power and energy monitoring requirements Communications options are also available For standard fixed capacitor applications where the customer requires a disconnect, Eaton can provide a unit with a main load break switch, fuse, inrush reactor, and 3-phase fixed delta capacitor cell This system can be provided at the following ratings: Predictive Diagnostics/Partial Discharge Detection Sensors can be mounted in medium voltage power factor correction systems to detect partial discharges in an enclosure and/or adjoining enclosures They can be connected to an InsulGardீ monitor mounted in the field, or mounted in the MV PFC enclosure The InsulGard monitor can ascertain the relative condition of insulation in the electrical distribution system, the deterioration of which is the leading cause of electrical failures With the InsulGard, there is no need to take equipment out of service or send personnel to conduct tests It constantly monitors its sensors and alerts the operator of a potential problem ■ 31 32 33 34 35 36 37 2.4 – 4.8 kV, up to 900 kvar, 94 H x 45 W x 49 D inches (2387.6 H x 1143.0 W x 1244.6 D mm), NEMA 3R enclosure ■ 5.5 – 14.4 kV, up to 2400 kvar, 94 H x 90 W x 49 D inches (2387.6 H x 2286.0 W x 1244.6 D mm), NEMA 3R enclosure (includes a ground switch) See Figure 37.6-3 and Figure 37.6-5 for structure outlines See Figure 37.6-4 and Figure 37.6-6 for one-line drawings Harmonic Filter Reactors Iron core reactors provide the necessary reactance to tune the capacitor system to a desired frequency Standard tuning is the 4.7th harmonic Other tuning frequencies, as well as multi-tuned systems, are also available 38 IQ Analyzer 6600 Circuit Breaker The VCP-TLC drawout type and VCP-TRLC fixed type medium voltage circuit breakers are available with short circuit breaking current ratings up to 25 kV and continuous current ratings up to 1200 amperes The linear actuator mechanism provides for a high degree of reliability with low maintenance needs Partial Discharge Sensor Connection Point Enclosure Options NEMA 4X construction for highly caustic environments or areas requiring wash down Other plant colors available Alarm Strobe Strobe light can be provided for visual indication of faults and alarms Current Transformer Automatic systems can be shipped with a customer-specified current transformer for mounting in the field 39 40 41 Harmonic Filter 42 43 For more information visit: www.EatonElectrical.com CA08104001E Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage June 2006 37.6-7 Sheet 1671 Technical Data Technical Data 22 23 Utility Line 24 Utility Transformer 25 Main Breaker CT A-Phase 26 27 28 Feeder Breaker 29 K0 30 Plant Loads 31 K-K Interlock K-K Interlock (Optional) 32 C C1 K-K Interlock K1 K0 Main Switch BLR-CM CPT 1-Phase Power Factor Controller 33 Tap On B&C K1 Ground Switch S1 34 S1 46 CT1 AS AM 59 S2 S3 Control Relays 35 Alarm or Trip 36 S1 37 Fuse Enclosure Door 38 C1 39 Vacuum Contactor 40 Reactor 41 42 Capacitor Delta/Wye Capacitor Delta/Wye Capacitor Delta/Wye Figure 37.6-1 Typical Medium Voltage Automatic Power Factor Correction Single-Line Drawing CA08104001E For more information visit: www.EatonElectrical.com 43 37.6-8 Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage June 2006 Sheet 1672 Layout Dimensions 22 ipping Split 23 24 25 Main witch 92.56 90.33 DANGE HIGH VOL KEEP OU 26 DANGER HIGH VOLTAGE KEEP OUT KE DANGER KEEP OUT Ground witch 27 28 49.10 29 45.00 1.50 (Typ) Front Right Side Elevation (Typ) 30 19.00 31 Incoming Conduit 19.00 Area 48.27 32 33 8.23 1.00 Floor Plan 34 Top Entry 19.00 MV Conduit Area Top Entry 16.00 Control Conduit 4" x 4" 13.00 15.00 38.00 4.00 35 36 37 38 Top View Figure 37.6-2 Typical Engineered Metal-Enclosed Power Factor Correction System Dimensional Data 39 40 41 42 43 For more information visit: www.EatonElectrical.com CA08104001E Power Factor Capacitors and Harmonic Filters Metal-Enclosed — Medium Voltage June 2006 37.6-9 Sheet 1673 Layout Dimensions 900 kvar / 2.4 kV – 4.8 kV Fixed Capacitor Bank 22 23 24 92.56 0.33 25 26 49.10 91 Right Side Elevation levation 45.00 1.50 Top Entry MV Conduit Area Top Entry Control Conduit 4" x 4" 4.00 Incoming Conduit d i 19.00 Area 48.27 Tiedown Points Per Enclosure Front & Rear For 1/2-Inch Hardware Floor Plan (Typ) 27 (Typ) 15.00 19.00 Right Side Elevation Front Elevation 49.10 19.00 19.00 8.23 Top Entry Control t Conduit 4" x 4" 48.27 Incoming Conduit 19.00 Area 16.00 4.00 38.00 Tiedown Points Per Enclosure Front & Rear For 1/2-Inch Hardware Estimated Weight: 3,400 lbs 29 13.00 Top View 30 Estimated Weight: 1,700 lbs 31 Floor Plan Figure 37.6-3 Fixed PFC Outline Drawing — Structure Figure 37.6-5 Fixed PFC Outline Drawing — Structure 5.5 kV – 14.4 kV Fixed Capacitor Bank From Customer's Feeder Breaker 2.4 kV – 4.8 kV, 3-Phase KO-KO Interlock at Customer Breaker K0 K1 1L 1N 20 A 120 V/10 KAIC Fuse 63 kAIC 15.5 kV TSF1 40ºF 80ºF H1 Ground Switch F1 S1 Inrush Reactor F11 Fans: Fans 115 V/60 Hz/0.5 A Fuse 63 kAIC 5.5 kV F1 F11 Inrush Reactor Fans: 115 V/60 Hz/0.5 A F12 Space Heater: 120 V/60 Hz/350 W Enclosure S1 Door HTR1 Capacitor Bank Control Schematic Single-Line Figure 37.6-4 Fixed PFC One-Line Drawings Space Heater: 120 V/60 Hz/350 W Capacitor Bank Control Schematic Single-Line Figure 37.6-6 Fixed PFC One-Line Drawings For more information visit: www.EatonElectrical.com 38 39 Enclosure K1 Door Cutler-Hammer is a federally registered trademark of Eaton Corporation NEMA is the registered trademark and service mark of the National Electrical Manufacturers Association National Electrical Code and NEC are registered trademarks of the National Fire Protection Association, Quincy, Mass UL is a federally registered trademark of Underwriters Laboratories Inc CSA is a registered trademark of the Canadian Standards Association Modbus is a registered trademark of Modicon, a division of Schneider Electric Industries SA CA08104001E 36 37 TSF1 40ºF 80ºF H1 35 GND BUS #12 (WH) Fans F12 HTR1 1N Main Switch TSH1 K1 K0 K1 20 A 120 V/10 kAIC #12 (BK) 1 TSH1 1N G TB1-1N TB1-G TB1-1L #12 (BK) 1L GND BUS #12 (WH) 1L Main Switch 33 34 K0 From Customer's 120 Vac Source 120 Vac/20 A, 1-PH, 60 Hz #12 (BK) #12 (BK) KO-KO Interlock at Customer Breaker K0 1N G TB1-1N TB1-G 1L TB1-1L 32 2.4 kV – 4.8 kV Fixed Capacitor Bank From Customer's Feeder Breaker 5.5 kV – 14.4 kV, 3-Phase From Customer's 120 Vac Source 120 Vac/20 A, 1-PH, 60 Hz 28 16.00 15.00 38.00 11.42 13.00 Top View Top Entry MV Conduit Area 19.00 40 41 42 43 37.6-10 Power Factor Capacitors and Harmonic Filters June 2006 Sheet 1674 22 This page intentionally left blank 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 For more information visit: www.EatonElectrical.com CA08104001E ... www.EatonElectrical.com CA08104001E June 2006 Power Factor Capacitors & Harmonic Filters Application Considerations 37.0-9 Sheet 1631 Motor Power Factor Correction Motor Power Factor Correction Tables 37.0-3... equipment will mitigate specific harmonic issues, and correct poor power factor as well UNIPAK Power Factor Correction Capacitors Power factor correction capacitors and harmonic filters are an essential... 37.0-8 Power Factor Capacitors & Harmonic Filters Application Considerations June 2006 Sheet 1630 Harmonic Considerations 22 23 24 25 26 27 28 29 30 31 32 33 Eliminating Harmonic Problems When power