I have an underground 240V circuit that the two hot legs are both broken, and the neutral is still intact. I have verified this with a meter. I need to find the location of the break (or burnout) so it can be repaired. I don't want to trench for a new cable because there are many other water lines and wires for a irrigation system in this area of yard. I tried a method I saw on youtube which involved using a wire connected to a lawn mower and to the underground wire and picking up signal with a portable AM radio. It works, but even thoug I had it connected to one of the broken wires, the signal bled over into the intact wire and continued to be picked up by the radio. I would like to know if anyone knows if a signal tracer available on Amazon such as the Noyafa NF-816, or something similar, would work, or would the signal bleed over through the intact wire.
You need a cable locator this is very much like a wire tracer but it uses the ground as part of the circuit. You transmit a signal over the cable and the signal returns through the ground to your receiver.
You normally use it to trace where a cable is located but you can use it to find a break in the cable as the sound will drop out suddenly where their is a break in the cable.
The short/open test set ECT3000 is not always giving enough information to find the location in case of interruptions. Maybe it is similar to the Noyafa.
An alternate option is a reflectometer. Maybe a test set could be rent for 1 hour.
A (digital USB-connected-) oscilloscope may also work. It has a rectangular waveform generator, whose signal can be fed into the cable. The time lag of the echoed signal gives the distance to the interruption (factor 2 is involved).
Either measurement should be done from both sides.
But the light/signal speed can be different from the vacuum light speed. The cable manufacturer should be able to provide that info.
Or a measurement with a second identical straight cable could serve to measure the speed.