PME connection and stupid idiots!

[NDG Elecs]

Hi,

Had a little beer tokens job on way home today fitting a couple of smoke alarms. When I got there I noticed what looked to be a PME intake with no main earth going to it. Done a couple of Ze's and found the top connection in the photo was defunct, but the earth in the separate terminal block at bottom of photo was getting 0.14 for Ze. Never seen this kind of PME set up before though.



Another thing I noticed is in the second photo. Bloody well annoyed me it did, and I told the landlord so. The cooker switch is less than four feet off the floor with the connection unit approx 2 ft. Took two minutes to remove the cable, why the hell it wasn't done when the oven was removed is beyond me. Two youngish kids living in the place as well..

 

[Hellmooth]

Little job on the way home.........did you surface trunk the cables? I do smoke alarms for an estate agents regularly and can't find a way to get it done as a little job on the way home lol!

 

[NDG Elecs]

It was just a couple of ten year battery fire angels mate. Landlord was aware of them and the cost of mains made him shudder!

Only charged a tenner for reinstating the main earth and removing the cooker cable. Should have charged more but the landlord seemed a nice, if a bit naive, fella. The gas and water bonds had Zs at sockets down to 3 ohms which was pretty darn good! 0.40 after main earth.

 

[Dave OCD]

So was the main earth to CU originally in the top PME earthing terminal and you reconnected it into the SP block below the DNO cutout ? Could even be TNS with the wrong cutout ?

 

[NDG Elecs]

So was the main earth to CU originally in the top PME earthing terminal and you reconnected it into the SP block below the DNO cutout ? Could even be TNS with the wrong cutout ?

Hi Dave. There was no main earth....bonding provided the equivalent of a half decent TT. The earth coming out of the bottom of the DNO earth block was fatter than 16mm and disappeared behind the back board. Thought possibility of TNS but Ze was 0.14 so sort of assumed PME. No matter I suppose as Zs's decent now. The top earth connection in picture one is simply there...it is not connected to anything internally within the cut out..

 

[Dave OCD]

Ah that's what make me wonder about it being TNS, the PME terminal at the top of the cutout is normally connected to the neutral within by a solid [removable] link but for some reason this wasn't utilised by the DNO ,but either way you now have a very good reading which is the main thing. In fact the whole DNO bit looks rough as old boots, really the double insulation of the tails should go all the way in and the shroud on the incoming supply cable is cut way too big.

 

[richy3333]

So was the main earth to CU originally in the top PME earthing terminal and you reconnected it into the SP block below the DNO cutout ? Could even be TNS with the wrong cutout ?

We have quite a few of these heads around our way where they are TNS and not PME'd. Ze can often be as low as a PME connection. Did you have time to measure the PSSC/PFC?

 

[stevethesparks]

Hi,

Had a little beer tokens job on way home today fitting a couple of smoke alarms. When I got there I noticed what looked to be a PME intake with no main earth going to it. Done a couple of Ze's and found the top connection in the photo was defunct, but the earth in the separate terminal block at bottom of photo was getting 0.14 for Ze. Never seen this kind of PME set up before though.

View attachment 29868

Another thing I noticed is in the second photo. Bloody well annoyed me it did, and I told the landlord so. The cooker switch is less than four feet off the floor with the connection unit approx 2 ft. Took two minutes to remove the cable, why the hell it wasn't done when the oven was removed is beyond me. Two youngish kids living in the place as well..

View attachment 29869

Not to mention the cooker switch is directly above the cooker position?

 

[NDG Elecs]

Hi,

Didn't check PFC, although that would have answered it. Looking at it I am guessing that when the intake was upgraded the DNO probably only had PME intakes on the van. Thinking about it, it likely is TNS as where the DNO earth disappears behind the back board that would make more sense. If PME the N would connect internally direct to the earth block at top of the intake. I have had an instance of a DNO lad needing to borrow a couple of feet of tails off me before so wouldn't surprise me if they didn't have decent stock on their van!

And yep, I noticed the positioning of the cooker switch. I mentioned to the owner that an I&T would be a good idea, will wait and see if he rings. At the time I was more concerned with the exposed conductors that were all to easily energised. Especially with youngsters about.