In the standard VDE0113 / EN60204 there is a table with cable lengths depending on rated current, conductor cross section and characteristic of the overcurrent protection element. If these line lengths are not exceeded, a loop impedance measurement on the fully installed machine will not exceed the required limit.
In the Profitest 204, these line lengths were converted into ohmic resistances. This allows you to check the machine in advance without being connected to the final installation site.
The setting depends on the type of overcurrent protection element and the cross section of the outer conductor. Cross section of the outer conductor, cross section of the protective conductor and rated current have a fixed assignment: