DEVItector™ II V2
User Guide
BC421332622232en-010101
18 | ©Danfoss | FEC | 2022.07
Fault no. 3 : Screen/conductor short circuit, i.e. a high leakage current may be measured
The resistance of the heating cable is OK. It is possible
to measure a finite resistance between conductor
and screen. The value will depend on the distance
between cold cable and fault.
In this case the idea is to use the short circuit between
conductor and screen for tracing.
No burning is required unless the short circuit turns out
to be unstable.
Fault no. 5 : Conductor (L/N) short circuit
The resistance of the heating cable is reduced,
depending on the distance between cold cable and fault.
The insulation resistance of the heating cable is OK.
In this case the connection between the two
conductors is used for tracing. No burning is required
unless the short circuit is unstable.
Fault no. 4 : Screen/conductor short circuit
The resistance of the heating cable is OK.
It is possible to measure a finite resistance between
conductor and screen. The value will depend on the
distance between cold cable and fault.
In this case the idea is to use the short circuit between
conductor and screen for tracing.
No burning is required.
As the end-terminated heating conductor is not
disrupted, the shortest path from cold cable to fault
is the one with the least resistance assuming identical
resistances of the two conductors. The longest path
(the lower conductor on the above sketch) will emit a
magnetic field along the entire heating cable.
Thus only the conductor having the shortest path will
make the tracing possible.
If it is impossible to determine the conductor
having the shortest path, it is necessary to trace the
cable twice, first with one and then with the other
conductor, respectively.
