Varistor Products High Energy Industrial Disc CA Varistor Series The CA Series of transient surge suppressors are industrial high-energy disc varistors (MOVs) intended for special applications requiring unique electrical contact or packaging methods provided by the customer. The electrode finish of these devices is solderable and can also be used with pressure contacts. Discs of the same diameter may be stacked. This series of industrial disc varistors are available in three diameter sizes of 32, 40, and 60mm, with disc thicknesses ranging from 1.8mm minimum to 32mm maximum. They offer a wide voltage range of from 250 to 2800 VM(AC)RMS . For information on soldering considerations, refer to AN8820 update. “Recommendations for Soldering Terminal Leads to MOV Varistor Discs”. Features • Provided In Disc Form For Unique Packaging By Customer • Solderable Electrode Finish Options • Pressure Contacts and/or Disc Stacking May be Utilized • Standard Disc Sizes 32mm, 40mm, and 60mm Diameter • Available Edge Passivation Insulation • Wide Operating Voltage Range VM(AC)RMS 250V to 2800V • High Peak Pulse Current Range . . . . . . . . . . ITM 20,000A to 70,000A • Very High Energy Capability WTM . . . . . . . . . . . . . . .330J to 10,000J • No Derating Up to 85oC Ambient 114 w w w. l i t t e l f u s e . c o m Varistor Products High Energy Industrial Disc CA Varistor Series For ratings of individual members of a series, see Device Ratings and Specifications chart CA SERIES Continuous: Steady State Applied Voltage: AC Voltage Range (VM(AC)RMS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 to 2800 DC Voltage Range (VM(DC)) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 to 3500 Transient: Peak Pulse Current (ITM) For 8/20µs Current Wave (See Figure 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20,000 to 70,000 Single Pulse Energy Range For 2ms Current Square Wave (WTM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 to 10,000 Operating Ambient Temperature Range (TA). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 to 85 Storage Temperature Range (TSTG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 to 85 Temperature Coefficient (αV) of Clamping Voltage (VC) at Specified Test Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <0.01 UNITS V V A J C O C %OC O CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Device Ratings and Specifications MAXIMUM RATINGS (85 oC) CONTINUOUS SPECIFICATIONS (25 oC) TRANSIENT VRMS VDC ENERGY (2ms) PEAK CURRENT (8/20µs) VARISTOR VOLTAGE AT 1mA DC TEST CURRENT MAX CLAMPING VOLT V C AT 200A CURRENT (8/20µs) TYPICAL CAPACITANCE SIZE VM(AC) VM(DC) WTM ITM MIN VN(DC) MAX VC f = 1MHz (mm) (V) (V) (J) (A) (V) (V) (V) (V) (pF) V131CA32 32 130 175 200 20000 184 200 228 350 4700 V151CA32 32 150 200 220 20000 212 240 268 410 4000 V251CA32 V251CA40 V251CA60 32 40 60 250 330 330 370 880 20000 40000 50000 354 390 429 680 650 620 2500 5000 10000 V271CA32 V271CA40 V271CA60 32 40 60 275 369 360 400 950 20000 40000 50000 389 430 473 750 730 680 2200 4500 9000 V321CA32 V321CA40 V321CA60 32 40 60 320 420 390 460 1100 20000 40000 50000 462 510 561 850 830 760 1900 3800 7500 V421CA32 V421CA40 V421CA60 32 40 60 420 560 400 600 1500 25000 40000 70000 610 680 748 1200 1130 1060 1500 3000 6000 V481CA32 V481CA40 V481CA60 32 40 60 480 640 450 650 1600 25000 40000 70000 670 750 825 1300 1240 1160 1300 2700 5500 V511CA32 V511CA40 V511CA60 32 40 60 510 675 500 700 1800 25000 40000 70000 735 820 910 1440 1350 1300 1200 2500 5000 V571CA32 V571CA40 V571CA60 32 40 60 575 730 550 770 2100 25000 40000 70000 805 910 1000 1600 1480 1420 1100 2200 4500 V661CA32 V661CA40 V661CA60 32 40 60 660 850 600 900 2300 25000 40000 70000 940 1050 1160 1820 1720 1640 1000 2000 4000 MODEL NUMBER w w w. l i t t e l f u s e . c o m 115 2 VARISTOR PRODUCTS Absolute Maximum Ratings Varistor Products High Energy Industrial Disc CA Varistor Series Device Ratings and Specifications (continued) MAXIMUM RATINGS (85 oC) CONTINUOUS SPECIFICATIONS (25 oC) TRANSIENT PEAK CURRENT (8/20µs) MAX CLAMPING VOLT V C AT 200A CURRENT (8/20µs) TYPICAL CAPACITANCE VRMS VDC ENERGY (2ms) SIZE VM(AC) VM(DC) WTM ITM MIN VN(DC) MAX VC f = 1MHz (mm) (V) (V) (J) (A) (V) (V) (V) (V) (pF) V751CA32 V751CA40 V751CA60 32 40 60 750 970 700 1050 2600 25000 40000 70000 1080 1200 1320 2050 2000 1880 800 1800 3500 V881CA60 60 880 1150 3200 70000 1290 1500 1650 2340 2700 V112CA60 V142CA60 V172CA60 V202CA60 V242CA60 V282CA60 60 60 60 60 60 60 1100 1400 1700 2000 2400 2800 1400 1750 2150 2500 3000 3500 3800 5000 6000 7500 8600 10000 70000 70000 70000 70000 70000 70000 1620 2020 2500 2970 3510 4230 1800 2200 2700 3300 3900 4700 2060 2550 3030 3630 4290 5170 2940 3600 4300 5200 6200 7400 2200 1800 1500 1200 1000 800 MODEL NUMBER VARISTOR VOLTAGE AT 1mA DC TEST CURRENT NOTE: Average power dissipation of transients not exceed 1.5W, 2.0W and 2.5W for model 32mm, 40mm and 60mm, respectively. 1. Peak current applies to applications rated up to 115VRMS. Peak Current is 30kA for applications greater than 115VRMS. 2. Peak current applies to applications rated up to 132VRMS. Peak Current is 30kA for applications greater than 132VRMS. Power Dissipation Ratings PERCENT OF PEAK VALUE Should transients occur in rapid succession, the average power dissipation result is the energy (watt-seconds) per pulse times the number of pulses per second. The power so developed must be within the specifications shown on the Device Ratings and Specifications table for the specific device. Furthermore, the operating values need to be derated at high temperatures as shown in Figure 1. Because varistors can only dissipate a relatively small amount of average power they are, therefore, not suitable for repetitive applications that involve substantial amounts of average power dissipation. PERCENT OF RATED VALUE 100 90 80 70 90 50 10 O1 60 50 40 T T1 TIME T2 O1 = Virtual Origin of Wave T = Time From 10% to 90% of Peak T1 = Virtual Front Time = 1.25 • t T2 = Virtual Time to Half Value (Impulse Duration) 30 20 10 0 -55 100 50 60 70 80 90 100 110 120 130 140 150 AMBIENT TEMPERATURE ( oC) Example: For an 8/20µs Current Waveform: 8µs = T1 = Virtual Front Time 20µs = T2 = Virtual Time to Half Value FIGURE 2. PEAK PULSE CURRENT TEST WAVEFORM FIGURE 1. CURRENT, ENERGY AND POWER DERATING CURVE 116 w w w. l i t t e l f u s e . c o m Varistor Products High Energy Industrial Disc CA Varistor Series Transient V-I Characteristics Curves TA = -55oC TO 85oC 2,000 V751CA32 V661CA32 V571CA32 1,000 V511CA32 900 V481CA32 800 V421CA32 700 600 V321CA32 500 V271CA32 V251CA32 400 3,000 10-2 1,000 900 800 700 600 V321CA40 500 V271CA40 10-1 100 101 102 PEAK AMPERES 103 104 V251CA40 400 V151CA40 6,000 5,000 4,000 MAX CLAMPING VOLTAGE DISC SIZE 60mm 250 TO 880VM(AC) RATING 3,000 TA = -55oC TO 85oC V131CA40 200 10-1 10-2 105 30,000 V511CA60 V481CA60 V421CA60 1,000 900 800 700 600 V321CA60 500 V271CA60 V251CA60 400 101 102 PEAK AMPERES 103 104 105 MAX CLAMPING VOLTAGE DISC SIZE 60mm 1100 TO 2800VM(AC) RATING 20,000 V881CA60 V751CA60 V661CA60 V571CA60 100 FIGURE 4. CLAMPING VOLTAGE FOR V131CA40 - V751CA40 MAX PEAK VOLTS (V) MAXIMUM PEAK VOLTS (V) 2 300 FIGURE 3. CLAMPING VOLTAGE FOR V131CA32 - C751CA32 2,000 TA = -55oC TO 85oC V751CA40 V661CA40 V571CA40 V511CA40 V481CA40 2,000 V421CA40 300 V151CA32 V131CA32 200 10-3 MAXIMUM CLAMPINGVOLTAGE DISC SIZE 40mm 130 TO 750 VM(AC) RATING VARISTOR PRODUCTS 3,000 6,000 5,000 4,000 MAXIMUM CLAMPINGVOLTAGE DISC SIZE 32mm 130 TO 750 VM(AC) RATING MAXIMUM PEAK VOLTS (V) MAXIMUM PEAK VOLTS (V) 6,000 5,000 4,000 10,000 9,000 8,000 7,000 6,000 TA = -55oC TO 85oC V282CA60 5,000 V242CA60 4,000 V202CA60 V172CA60 300 3,000 V142CA60 200 10-2 2,000 10-2 V112CA60 10-1 100 101 102 103 PEAK AMPERES (A) 104 105 FIGURE 5. CLAMPING VOLTAGE FOR V251CA60 - V881CA60 10-1 100 101 102 PEAK AMPERES (A) 103 104 105 FIGURE 6. CLAMPING VOLTAGE FOR V112CA60 - V282CA60 w w w. l i t t e l f u s e . c o m 117 Varistor Products High Energy Industrial Disc CA Varistor Series Pulse Rating Curves 50,000 50,000 2 10,000 105 10 5,000 1,000 103 500 104 200 100 50 20 100 1,000 IMPULSE DURATION ( µs) SURGE CURRENT (A) 2,000 103 500 200 100 106 50 FIGURE 9. 100 50 100 1,000 IMPULSE DURATION ( µs) 10,000 20,000 2 10 DISC SIZE 60mm V251CA60 - V321CA60 5,000 102 2,000 103 1,000 104 500 105 200 100 106 50 20 INDEFINITE 20 200 10,000 104 105 1,000 10 106 1,000 103 500 104 1 DISC SIZE 40mm V131CA40 - V751CA40 10,000 10 102 105 2,000 102 50,000 1 2 5,000 10 FIGURE 8. SURGE CURRENT RATING CURVES FOR V421CA32 - V751CA32 SURGE CURRENT (A) 20,000 5,000 10 20 10,000 FIGURE 7. SURGE CURRENT RATING CURVES FOR V131CA32 - V321CA32 50,000 DISC SIZE 32mm V421CA32 - V751CA32 2 20 INDEFINITE INDEFINITE 10 20 1 10,000 106 102 2,000 20,000 SURGE CURRENT (A) 20,000 SURGE CURRENT (A) DISC SIZE 32mm V131CA32 - V321CA32 1 100 1,000 IMPULSE DURATION ( µs) 10,000 SURGE CURRENT RATING CURVES FOR V131CA40 - V751CA40 100,000 50,000 20,000 INDEFINITE 100 1,000 IMPULSE DURATION ( µs) 10,000 FIGURE 10. SURGE CURRENT RATING CURVES FOR V251CA60 - V321CA60 DISC SIZE 60mm V421CA60 - V282CA60 1 10 20 10 20 2 SURGE CURRENT (A) 10,000 5,000 102 2,000 103 1,000 104 500 105 200 100 106 50 20 10 20 INDEFINITE 100 1,000 IMPULSE DURATION ( µs) 10,000 FIGURE 11. SURGE CURRENT RATING CURVES FOR V421CA60 - V282CA60 NOTE: If pulse ratings are exceeded, a shift of VN(DC) (at specified current) of more than ±10% could result. This type of shift, which normally results in a decrease of VN(DC), may result in the device not meeting the original published specifications, but does not prevent the device from continuing to function, and to provide ample protection. 118 w w w. l i t t e l f u s e . c o m Varistor Products High Energy Industrial Disc CA Varistor Series Series Dimensions OPTIONAL PASSIVATION COLLAR 2.0 DISC DIAMETER 0.25 ELECTRODE DIAMETER (SEE TABLE) MILLIMETERS INCHES MODEL SIZE MIN MAX MIN MAX 32 31.0 33.0 1.220 1.299 40 38.0 40.0 1.496 1.575 60 58.0 62.0 2.283 2.441 2 VARISTOR PRODUCTS ELECTRODE THICKNESS THICKNESS (32mm DISC MODELS) THICKNESS (40mm AND 60mm DISC MODELS) MODEL VRMS VM(AC) MIN MAX MIN MAX MIN MAX MIN MAX 130 † 1.4 2.4 0.071 0.094 1.4 2.8 0.055 0.134 150 † 1.7 2.8 0.083 0.110 1.5 3.0 0.06 0.150 250 1.6 2.2 0.063 0.087 2.0 2.7 0.079 0.106 275 1.8 2.5 0.071 0.098 2.2 3.0 0.087 0.118 320 2.1 2.9 0.083 0.114 2.6 3.5 0.102 0.138 420 2.9 3.9 0.114 0.154 3.5 4.7 0.138 0.185 480 3.1 4.3 0.122 0.169 3.8 5.2 0.150 0.205 510 3.5 4.7 0.138 0.185 4.2 5.7 0.165 0.224 575 3.8 5.1 0.150 0.201 4.6 6.3 0.181 0.248 660 4.4 6.0 0.173 0.236 5.3 7.2 0.209 0.283 750 5.1 6.9 0.240 0.327 6.1 8.3 0.240 0.327 880 †† - - - - 7.3 10.3 0.287 0.406 1100 †† - - - - 9.2 13.0 0.362 0.512 1400 †† - - - - 11.5 16.0 0.453 0.630 1700 †† - - - - 14.0 19.0 0.551 0.748 2000 †† - - - - 17.0 22.5 0.669 0.886 2400 †† - - - - 20.0 27.0 0.787 1.063 2800 †† - - - - 24.0 32.0 0.945 1.260 MILLIMETERS INCHES MILLIMETERS INCHES † Available in 32mm and 40mm only. †† Available in 60mm size only. w w w. l i t t e l f u s e . c o m 119 Varistor Products High Energy Industrial Disc CA Varistor Series SIZE (mm) TYPICAL DISC WEIGHT (GRAMS) V131CA32 V131CA40 32 40 9 21 V151CA32 V151CA40 32 40 11 23 V251CA32 V251CA40 V251CA60 32 40 60 8 17 39 V271CA32 V271CA40 V271CA60 32 40 60 10 18 42 V321CA32 32 11 V321CA40 40 22 V321CA60 60 50 V421CA32 32 15 V421CA40 40 28 V421CA60 60 66 V481CA32 32 16 V481CA40 40 31 V481CA60 60 71 V511CA32 32 18 V511CA40 40 35 V511CA60 60 80 V571CA32 32 20 V571CA40 40 38 V571CA60 60 88 V661CA32 32 23 Encapsulated Recommendations After lead attachment, the disc/lead assembly may be coated or encapsulated in a package to provide electrical insulation and isolation from environmental contamination as required by the application. Coating/Filler materials for containers may include silicones, polyurethanes, and some epoxy resins.Two examples of acceptable polyurethanes are Dexter Hysol (US7013, parts A and B) and Rhenatech (resin 4714, hardener 4900), or their equivalents. Materials containing halogens, sulfides, or alkalines are not recommended. Electrode Metallization The standard CA Series is supplied with sintered silver electrodes on CA32 devices and arc-sprayed copper-over-aluminum electrodes for CA40 and CA60 series. CA40 parts are also available with sintered silver electrode, see “Ordering information.” In general, when discs are stacked to attain a specific operating voltage or energy capability, the copper finish is typically chosen. Likewise, the copper finish is used with high temperature lead attach soldering operations (wave solder). The silver metallization is typically used for solder reflow lead attach operations (I-R, Vapour-Phase). The recommended temperature profile of a belt-fed convection oven is shown in Figure 13. 250 200 TEMPERATURE ( oC) MODEL NUMBER 150 100 50 V661CA40 40 44 V661CA60 60 101 V751CA32 32 26 V751CA40 40 51 V751CA60 60 116 V881CA60 60 141 V112CA60 V142CA60 V172CA60 V202CA60 V242CA60 V282CA60 60 60 60 60 60 60 178 220 265 317 377 450 0 0 100 200 300 400 500 600 700 800 900 TIME (SEC) FIGURE 13. TYPICAL BELT OVEN TEMPERATURE PROFILE Stacking and Contact Pressure Recommendations When applications require the stacking of Littelfuse CA discs or when electrical connection is made by pressure contacts, the minimum pressure applied to the disc electrode surface should be 2.2kGs (5 pounds). The maximum recommended pressure applied to the disc electrode is dependent upon diameter size and is given in the following table. MODEL SIZE (mm) MAXIMUM PRESSURE 32 16N/CM2 (23LBs/IN2) Passivation Layer 40 8N/CM2 (11.5LBs/IN2) The standard CA Series is supplied with passivation layer around the outside perimeter of the disc forming an electrical insulator as detailed in the dimensional drawing. The CA Series is also available without a passivation layer for applications where the customer provides a suitable encapsulation or potting material as recommended below. (See Ordering Information.) 60 4N/CM2 (5.7LBs/IN2) 120 w w w. l i t t e l f u s e . c o m Varistor Products High Energy Industrial Disc CA Varistor Series Ordering Information NOTES: 1. The 60mm disc types V112CA60 to V282CA60, inclusive, are only supplied with glass passivation and arc-sprayed copper finish electrodes. (That is, with the “PC” option suffix code.) 2. The 32mm size discs are only available with silver metallization. Note also that the CA Series receives no branding on the disc itself. ELECTRODE MATERIAL NON-PASSIVATED DISC PASSIVATED DISC Arc-Sprayed Copper NC PC Sintered Silver NS PS 2 Packaging and Shipping The CA Series is supplied in bulk for shipment. Discs are packaged in compartmentalized cartons to protect from scratching or edge-chipping during shipment. V 25 1 CA 40 P S SILVER ELECTRODE OPTION DESIGNATOR VARISTOR DESIGNATOR PASSIVATION OPTION DESIGNATOR MAX AC RMS WORKING VOLTAGE (FIRST SIGNIFICANT DIGITS) V M(AC) DISC SIZE (mm) DIAMETER VM(AC) VOLTAGE DECADE MULTIPLIER SERIES DESIGNATOR w w w. l i t t e l f u s e . c o m 121 VARISTOR PRODUCTS The CA Series offers optional electrode finish materials and a glass passivation edge option which must be designated. When ordering, the code letters suffix as shown in the following table must be selected and appended to the standard Model number.