VDR Silicon Carbide Varistors

Application Data

Technical Properties for VDR Silicon Carbide Varistors:

Characteristic	Value
Operating Voltage	5 to 460 V
Nominal Diameter	12.5 to 80 mm
Exponent	2 to 7
Energy Absorption	7 to 1900 J
Continuous Rating	0.5 to 19W
Reaction Time	< 10 ns
Operating Temperature at Zero Load	- 40 °C to + 130 °C
Operating Temperature at Full Load	- 40 °C to + 55 °C
Temperature Coefficient:
Of Voltage at Constant Current	- 0.12 to - 0.18 % / K
Of Current at Constant Voltage	- 0.5 to 0.8 % / K

Selection of Type

Silicon carbide varistors are classified as follows:

For Example 125 SDL 1,0K/6

125	= Nominal Diameter in mm Disc Types 7.5 / 10 / 12.5 / 17.5 / 25 / 40 / 60 / 80 / 85 / 105 mm Nominal Diameter. The Installation Diameter of SDL Types is larger than the Nominal Diameter because of the lacquer coating.
S/R	= Shape: S = Disc, R = Roll
D/B	= Mode of Connection: D = Wire Connection, B = Plug In or Screw Connection
L	= Coating: L = Lacquered
1,0K	= B Value: Voltage at 1 A
/6	= Exponent: Slope of the U / I Curve
W	= Preferred Type for AC Voltage use (measuring voltage ~)

Technical Data

The specified maximum values are absolute limits.

The maximum permissible load of a varistor is reached when one of the specified maximum values will be exceeded, even if the other limits have not been reached.

Type	Maximum Power Dissipation at Δt = 80 °K (Watts)	Mean Impact Strength (Joules)
125S / SD / SDL	0.8	18
250S / SD / SDL	2	100
400S / SD / SDL	3	250
410 SB	3	250
610 SB	5	600
820 SB	19	1900
100R / RD / RDL	1	45