Littelfuse CA Varistor Series - Manual (Page 2)

© 2013 Littelfuse, Inc. 182
Revised: May 8, 2013
Varistor Products
CA Varistor Series
High Energy Industrial Disc Varistors > CA Series
Specifications are subject to change without notice.
Please refer to www.littelfuse.com/series/ca.html for current information.
CA Series Ratings & Specifications
Part
Number
Device Branding
Size
Maximum Rating (85°C) Specifications (25°C)
Continuous Transient
Varistor Voltage at 1mA
DC Test Current
Max Clamping
Volt Vc at 200A
Current
(8/20μs)
Typical
Capacitance
V
RMS
V
DC
Energy
(2ms)
Peak
Current
(8/20μs)
V
M(AC)
V
M(DC)
W
TM
I
TM
Min V
NOM
Max V
C
f = 1MHz
(mm) (V) (V) (J) (A) (V) (V) (V) (A) (pF)
V251CA60 60 250 330 880 50000 354 390 429 620 10000
V271CA60 60 275 369 950 50000 389 430 473 680 9000
V321CA60 60 320 420 1100 50000 462 510 561 760 7500
V421CA60 60 420 560 1500 70000 610 680 748 1060 6000
V481CA60 60 480 640 1600 70000 670 750 825 1160 5500
V511CA60 60 510 675 1800 70000 735 820 910 1300 5000
V571CA60 60 575 730 2100 70000 805 910 1000 1420 4500
V661CA60 60 660 850 2300 70000 940 1050 1160 1640 4000
V751CA60 60 750 970 2600 70000 1080 1200 1320 1880 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
8800
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
NOTE: Average power dissipation of transients should not exceed 2.5W for CA60 discs.
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 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
50
10
O
1 T
T
1
T
2
TIME
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 μs Current Waveform:
8μs = T
1
= Rise Time
20μs = T
2
= Decay Time
100
90
80
70
60
50
40
30
20
10
0
-55 50 60 70 80 90 100 110 120 130 140 150
AMBIENT TEMPERATURE ( o C)
PERCENT OF R
A
TED
V
ALUE
Figure 1 Figure 2