How to locate a fault on a circuit

[Clna68]

Is there a formula to find a fault on a circuit if you know it is 75 feet long and you have 8 ohms on one end and 4 ohms on the opposite end

 

[iceworm]

We need a little more context - Or I do any way.

What is the circuit?

Two conductors in conduit?​

Something else?​

​

What is the wire size?

What is the nature of the fault?

Two conductors shorted together?​

One conductor shorted to conduit?​

Something else?​

 

[charlie b]

I will add that I do not understand what you mean by the two resistance measurements. How did you do the measurements, with what type of instrument, and to what did you attach the instrument's probes? In any event, there will not be a formula for just this situation. But it may be possible to discern the location of a fault, if more information were provided.

 

[retirede]

If we presume that you are referring to a simple two wire circuit that has the same gauge wire throughout and are trying to locate the point in the circuit where the two wires are shorted together, then you can simply ratio the resistance. In this case, it’s 1/3 of the total distance (25’) from the 4 ohm end.

 

[ptonsparky]

That’s some pretty small wire.

You are also hoping they are shorted in only one place and not two