Locate Underground High Voltage Power

Locate Underground High Voltage Power Cables

Underground high voltage power cables (HV) can be a scary prospect. Technically anything over 1000 Volts is classified as HV in Australia. We use high voltage power cables as transmission lines to take power over long distances. The majority of the High Voltage cables you’ll come across in Australia are going to be 66,000 Volts or 132,000 Volts, nothing to sneeze at. It goes without saying (but i’ll say it anyway) that safety is the utmost priority when working around such networks.

As always, your best first course of action is for you to request Dial Before You Dig (DBYD) plans for the area you’re interested in. Always keep in mind that with Dial Before You Dig you aren’t likely to get any information on private services, though they are very useful for working in public areas.

Things can possibly get tricky from there depending on the environment. The biggest obstacle with live HV is that is too dangerous to get close to induction points so some second order locating techniques often have to be employed. It’s possible to get a read in an uncontested area using passive induction power scanning, that will be a good starting point, but not enough to go on with. You’ll want to detect a point on the cable using existing plans, passive induction or two person induction sweeping. Then use induction on top of the cable to locate the remaining line.

It’s often a lot more difficult than it sounds to locate HV, certainly not impossible though. The nature of HV is that is requires a significant protection system built into the cable and often into the environment its installed into. There is a jacket of insulation around the cable that can create some issues with inducting your signal. Other problems may be caused by concrete barriers installed over the cable, or the depth needed for the cable to be safely installed.