Varistor Metal Oxide Varistor Products Page 176 Varistor Metal-Oxide Varistor Products

2017 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 09/14/17 Metal-Oxide Varistors (MOVs) Industrial High Energy Terminal Varistors > DA/DB Series Note : Average power dissipation of transients not to exceed 2.0W. DA/DB Series Ratings & Specifications Part Number Device Branding Maximum Rating (85C) Specifications (25C) Continuous Transient Varistor Voltage at 1mA DC Test Current Maximum Clamping Volt V C at 200A Current (8/20 s) Typical Capaci- tance f = 1MHz V RMS V DC Energy (2ms) Peak Current 8 x 20 s V M(AC) V M(DC) W TM I TM Min V NOM Max V C DA DB (V) (J) (A) (V) (A) (pF) V131DA40 V131DB40 130 175 270 40000 1 184.5 205 225.5 345 10000 V151DA40 V151DB40 150 200 300 40000 2 216 240 264 405 8000 V251DA40 V251DB40 250 330 370 40000 351 390 429 650 5000 V271DA40 V271DB40 275 369 400 40000 387 430 473 730 4500 V321DA40 V321DB40 320 420 460 40000 459 510 561 830 3800 V421DA40 V421DB40 420 560 600 40000 612 680 748 1130 3000 V481DA40 V481DB40 480 640 650 40000 675 750 825 1240 2700 V511DA40 V511DB40 510 675 700 40000 738 820 902 1350 2500 V571DA40 V571DB40 575 730 770 40000 819 910 1001 1480 2200 V661DA40 V661DB40 660 850 900 40000 945 1050 1155 1720 2000 V751DA40 V751DB40 750 970 1050 40000 1080 1200 1320 2000 1800 Should transients occur in rapid succession, the average power dissipation required is simply 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 above. 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. Power Dissipation Ratings 100 90 80 70 60 50 40 30 20 10 0 -55 50 60 70 80 90 100 110 120 130 140 15 PERCENT OF RATED VALUE AMBIENT TEMPERATURE ( o C) 100 90 50 10 O 1 T 1 T 2 TIME PERCENT OF PEAK VALUE Peak Pulse Current Test Waveform 0 1 = Virtual Origin of Wave T = Time from 10% to 90% of Peak T 1 = Rise Time = 1.25 x T T 2 = Decay Time Example - For an 8/20 s Current Waveform: 8 s = T 1 = Rise Time 20 s = T 2 = Decay Time NOTES: 1. Peak current Applies to applications rated up to 115VRMS. Peak current is 30kA for applications greater than 115V. 2. Peak current applies to applications rated up to 132VRMS. Peak Current is 30kA for applications greater than 132V. Figure 1 Figure 2

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