I wonder how often this happens

[John Rumm]

A friend was asking why when his friend was moving a washing machine he kept getting shocks off it, and did I think there might be something up with the wiring. Anyway, it sounded like it needed further investigation so we went round for a peak.

It turns out it is a ten year old house they moved into a month ago, and the description given by the owners sounds like we are not talking just about static. So I explained it could be a fault with the earthing in the kitchen, and that combined with either a genuine hard fault in the (now disposed of) old machine, or possibly the normal issue of mains input filters and a poor earth, would explain it.

Plugged a socket tester into a kitchen socket - no earth at all! Loop tester conformed complete open circuit. So I suggested we inspect the CU etc.

Standing there looking at it, I was thinking "am I missing something here?". Modern split load CU, TN-C-S head end, main equipotential bonds in place (even if the water pipe one was undersize)... but no connection

*at all* between the earth terminal on the suppliers cable head end and the CU!

Suggested that this was less than optimal and they ought have words with their supplier PDQ. Repeated earth loop tests on some other sockets and got a reading of 30 ohms or so (probably just the fortuitous earthing from the main EQ bonds). (oddly the RCD did not trip even here which would suggest yet another fault in addition to the circuit fault in the kitchen).

Anyway the supplier came and looked, agreed with the diagnosis, but then said they had to get their own sparks to make the earth connection. (This surprised me a little since I would have expected them to be happy to make a connection to their head end).

Just shows how useful surveys are in these cases!

[Colin Wilson]

Is there actually an earth at the cutout ? - they're not obliged to provide an earth, and depending on network factors, may not be possible to provide an earth. This is common where supplies are via two-wire overhead lines, so depending on how rural the location is...

Coastal areas are prone to earthing issues - when the tide comes in, it's great, but as soon as it goes out again it's crap...

If that's the case, it's time to start sinking earth rods :-}

[Colin Wilson]

I forgot to ask - was the earth connection on the cutout exposed ? - if not, that might be an indication that an earth isn't available.

If it was exposed, you could have just done it yourself as it was available.

[John Rumm]

It was a PME cable end type a bit different from the one I usually see, but still obviously intended to be a be PME one. It had what was either SWA or possibly concentric supply into the base of it (emerging from the garage floor) and three grommeted outlets on top, on with live tail, one neutral and an adjacent one with nothing fitted. The CU was obviously fitted out with the assumption of a TN variant rather than TT and there were no local earth stakes etc).

I did not examine the head end block that closely to see if there was an obvious way of accessing just the earth terminal - since I assumed at that point it would be something the supplier would rectify.

No, this was in a major town with underground supplies to the properties.

Anyway, after his conversation with the supplier (who confirmed they do supply an earth) he had an electrician fit the earth for him - so I guess it must have been straightforward enough. Must check at some point if he also had him track down the other faults.