Basic insulation exposed in electrical outdoor meter box.

I acknowledge that there are more pressing matters to address; however, is this forum not intended for discussions related to BS 7671?

The question arises due to the increasing acceptance of terminating SWA cable cores directly into an REC isolator within an external wall-mounted meter box. This practice does not comply with regulations 134.1.1, 526.8, and 521.10.1. 

The DNO does not own the cupboard, so what entitles it to say what may be in there?

The conditions of the supply contract, I would imagine...

   - Andy.

We have two identical "meter cupboards" side-by-side, but they could be one (bigger, obviously) cupboard. The DNO does not own the cupboard, so what entitles it to say what may be in there? By contrast, in the garage, the cupboard is the garage with the DNO's tackle and switch-fuse side-by-side. (We have two supplies.)

Chris Pearson said:

In the case of a switch-fuse, is not the device DB1, and at the other end DB2 (probably the house's CU)?

But the issue here is whether the switch-fuse ought to be in the meter cupboard. I don't think the product standard for the meter cupboard has considered equipment not belonging to the DNO/meter operator being in there.

whjohnson said:

think first

... Which is best done by writing down the problem and attempting to vocalise the problem with a specific question (it's why writing down notes in school/college/university classes works well..). I often find that once the [my] question has been formulated, that the release of frustration happens after pressing 'send', that the [my] brain can then allow itself some free thinking and bring forward alternate 'obvious' (isn't hindsight wonderful) solutions. When we receive such queries we often forget that the obvious answer shouldn't be over analysed.

I suspect that in this big discussion we have the classic scissors/paper/stone arguments at the three registration levels, and we have a massive round robin of finger pointing. Those who maintain standards need clarity about those standards. Those that interpret standards need an understanding of the rationale, and those that create/update standards depend on those that maintain the standards. [we all are standing on shoulders of giants etc.]. 

.. Not sure if I was meant to reply :wink: .

Thanks GK, that's a useful clarification for my side query.

AJJewsbury said:

Generally we just don't trust basic insulation alone to provide adequate protection against shock

Perhaps with wiring systems, but that's not 'generally' the case across BS 7671. IP2X/IPXXB is generally sufficient - no socket-outlet would otherwise be practicable.

Biggest exception is the case of GLS lampholders where even IP2X is unnecessary.

Agree. I think the best approach is to think first and ask yourself why you are asking the question in the first place. In the majority of instances when this approach is adopted, the questioner suddenly finds that there is no real need to ask in the first place and that the answer is self evident when a smidgeon of thought is applied upfront.

If however, the questioner persists, then at least give a reason why you are asking and what your thoughts are on the suject.

is there a risk of shock? Electricity meter boxes conforming to the relevant British Standard do have an electricity warning sign moulded into the door, so there is a warning to take care ... and all parts should be covered with at least basic insulation ?

Generally we just don't trust basic insulation alone to provide adequate protection against shock - twisted twin went out with the ark, basic insulation showing elsewhere in an installation would normally be coded C2 (not an immediate danger, but could be if the basic insulation failed or was damaged - still a fail on an EICR) - why treat this any differently?

What's worse, it deprives the good electrician of an argument against patent bad practice ... bare wires under a bath (behind a screwed on panel) or under a floorboard? no problem says the cowboy - it's only accessible using a tool...

   - Andy.

AMK said:

I believe it’s more a rule of thumb precaution due to supply loop impedances as DNOs are under no legal obligation to provide or maintain any particular value of earth loop impedance and during the lifetime of an installation a number of circumstances may alter the earth fault loop impedance

Legal obligation or not, when I reported a slightly high Ze (say 1.05 Ω) to my DNO, they were round like a shot. There was some debate between the operatives as to whether to leave me connected. Within the day, they had dug up the side lawn (using a road breaker 'cos the weather was the same as now) and "PME'd" the supply.