Electrical board: Location of main feed???

[Styx]

Well just had MEB come out. They needed to change the feed to the house I am renting.

We have at present an Earth-rod (somewhere?? cant find it mind) BUT the agency that my lass and I rent off had their sparky change some of the wiring, as a result we had to have an earth-feed from the grid.

MEB turned up dug a 1'x1'x1' hole in exactly the right place outside the house to find the existing feed, cut it, pull it out and replace with a new one.


How the hell did they locate the feed so precily (the feed from the grid was in the center of one of the holes sides)

We are near no electrical manhole for them to look down?
just wandered?

 

[Nigel Goodwin]

How about a metal detector?, or detecting the magnetic field around the cable?.

They might even have used a dowsing rod?, I've seen them used for electric cables as well as water pipes.

 

[Styx]

oh yer didnt think of that

 

[stevez]

Lots of good tools exist that help in locating underground utilities. In some cases a transmitter is placed on a line, conduit or other conductor. A fairly sensitive reciever is used to pinpoint the location. Many of the devices are about 1 meter long with a handle readout on one end and the sensor that is close to the ground at the other end - so the user can walk along and find the item of interest. Some work as Nigel suggests on the magnetic field - others look for a specific signal. Ground penetrating radar is used for larger surveys.

In many areas here in US it's mandatory to have what's called a "stake-out" done before digging. Crews from various utility companies show up with all sorts of locators. Each one locates their item quickly with the portable tools then spray paints on the walk, grass ,whatever.

One other possibility is that there might have been clues that you just don't recognize - a bump in the wall, a conduit or meter inside.