
The arrester consists of ZnO tablet placed inside ceramic tube. Electrodes are connected to the end tablets.
Analysis Type:
An axisymmetric problem of Transient electric field.
Geometry:
Given:
Relative permittivity of air ε = 1.
Relative permittivity of ceramic ε = 2.
Relative permittivity of ZnO element ε = 60.
Conductivity of ZnO element  nonlinear.
Nominal voltage U_{0} = 35 kV.
Maximal current I_{max} = 520 A.
Surge voltage U_{max} = 200 kV.
Problem:
Calculate the varistor current.
Solution:
The arrester can be represented by the equivalent schema with resistor R and capacitance C connected in parallel.
At nominal voltage the arrester acts as a capacitance (I_{C}>I_{R}). At overvoltage (surge) I_{R} prevails and varistor acts like a resistor. QuickField can calculate both active (I_{R}) and reactive (I_{C}) currents.
Results:
Voltage 
Active Current 
35 kV 
0.67 mA 
197 kV 
433 A 
Surge impulse passing through the arrester
See the Telec2.pbm problem in the Examples folder.