Conduit used as Earth

[m4tty]

Hi,

In my house all the wiring is in conduit buried in the concrete walls. The conduit is used as the Earth.

I was just having a play with new tester doing continuity tests on the earth from MET to copper pipework (all below 0.05ohms) and tested on the backboxes for lightswitches and sockets and got readings from 0.05ohms to 2.89ohms.

Does this sound alright .... 2.89ohms???

Just trying to learn and get used to the tester.

Thanks

 

[sellers]

2.89s a bit high if your relying on the conduit as an earth, are you sure you got a clean contact with your probe. Could have a loose joint somewhere

 

[Lurch]

Sounds like the tester is working, and your conduit is corroding!

 

[Andy™]

most likely corrosion as lurch says. many old conduits i remove whilst doing work are very rusty