Hey Stian,
To test faults selectively, I assume you want to test each fault in isolation. This can be best achieved using Variant Bounded Regions. This approach allows you to design all the faults and connect them appropriately, while enabling the simulation to programmatically select the fault you want to simulate, instead of requiring you to manually change the connection for each simulation. This is accomplished in tandem with the Variant Connector Block.
You can refer to the following guide to get started:
Alternatively, you can launch the above from the command line using:
openExample('simscape/VariantBoundedRegionInElectricalCircuitExample')
The following documentation for the Variant Connector Block should help you connect each fault as a variant:
