Cylindrical fuse operation time

QuickField simulation example

This is an example of the safety fuse simulation, performed with QuickField software.

Engineering question
How to find fuse heating during short-circuit conditions

Engineering answer
Set up a plane-parallel QuickField Multiphysics problem for a cylindrical fuse and evaluate heating under fault-current conditions from computed field results.

Typical applications
cylindrical fuses, short-circuit protection devices, fuse elements

• Download simulation files (files may be viewed using any QuickField Edition).

Problem Type
Axisymmetric multiphysics problem of DC conduction coupled to Transient heat transfer.

Geometry

Given
Conductor diameter: 0.2 mm;
Rated current I0 = 5 A.
Fault current I = 20 A.
Ambient air temperature T0 = 20 °C;
Conductor melting point T = 240 °C;
Quartz sand thermal conductivity λ = 0.3 W/m-K.

Task
Determine the cylindrical fuse operating time.

Result
Fuse resistance 0.041 Ohm. The temperature will reach conductor melting point 0.5 seconds after the fault.

• Video: Cylindrical fuse operation time. Watch on YouTube
  
• Download simulation files (files may be viewed using any QuickField Edition).