Martindale Socket Tester EZ150

[Mikey]

Hi,

Will this tester indicate possible earth cable deterioration when connecting to an outside socket as i have three outdoor sockets which were all working fine but one of them is now tripping my fuse box and would like to determine which one it is before replacing the cable?

[John Rumm]

Looking at the manual:

It appears to be able to measure earth loop impedance and give an indication of which of 7 possible bands the result falls. So if you know your earthing system[1], and the expected impedance reading, it could give an indication of a problem.

[1]

Could you clarify what you mean by "tripping your fuse box"?

It would be quite common for example for exterior electrics to present high earth leakage currents that would trip a typical RCD[2]. However a poor earth connection is unlikely to make that any more likely.

Moisture ingress, insulation breakdown, insect life in electrical enclosures however would make RCD trips more likely. MCB[3] trips would be more typically associated with cable damage.

[2]

Testing and identifying the source of the fault is worth doing certainly. However don't assume necessarily that its a cable fault, or specifically a poor earth connection fault.

[Brian Gaff (Sofa 2)]

I think I'kd just break each circuit at the most logical place and then reconnect them till it starts to trip. I dont like outdoor electric sockets and plugs. Brian

[Mikey]

replying to John Rumm, Mikey wrote: Thanks John, All was fine until a few weeks ago and now the fuse box keeps tripping after a few hours when my outside appliances are turned on from the fused switch. I have isolated and checked all the outside sockets and appliances which are fine however i did notice one of the earth copper cables which was feeding my pump was displaying green corrosion. Regards Mike

[John Rumm]

With circuits and the stock market, previous performance is no indication of future...

We could probably give more specific advice if you made it clear what is tripping in the fuse box.

Is this actually a fuse that is blowing, a circuit breaker (MCB) that is tripping, or a RCD that is tripping?

[Dave Plowman (News)]

Unless a cable had been physically damaged, more likely damp and dirt etc in a socket. Give them all a good clean out and dry, first.