Metal Supply Cupboard Used As MET

[Shaun-]

Hi, first time poster, long time lurker. Guess I'll have to start getting involved...


Just looking for some advice really on something I haven't come across before (I don't usually work on farms).

So I'm working on an installation that is TN-C-S (PME too) and I'm putting in a new TT sub-main to a metal container. Obviously TN-C-S is not preferred on a farm but that's "how its always been" and by the sounds of it / nature of the installation it hasn't caused any issues with animals.

When looking at the incomer I have noticed that the main earth doesn't have a MET and is just bolted into the metal casing; with other earths to sub-mains on the same bolt or bolted in close by. Continuity testing and EFLI is coming back ok suggesting no high impedance connections between these.



I have discussed complete isolation of supply to add in a MET but apparently this isn't an option.

Am I right in thinking this is not acceptable even though tests ok or would this be allowed?
If this is a departure what regulation would you list this under on the EIC?

Thanks

Shaun

 

[James]

As a general rule of thumb,

if it is on a farm,

it has been done cheep

it has since been bodged and messed about with by several people who “know about electricity”

is full of dust
rusting away
the covers have been removed and lost many years ago

however to address the point you have raised,
many old and some new distribution boards use their own frame as a point of earthing but normally you would find an earth bar inside that is bolted to the frame for outgoing circuits and any other earth conductors.

if it is good continuity and mechanically sound I would not be concerned.

but my preference when seeing something like that would be to have a nice shiny copper bar with a row of crimped lugs bolted to it.

edit,
p.s. whatever you find will be deemed as safe by the farmer because

“everyone knows that you have to use this piece of wood to operate that thing with the exposed terminals”

 

[Shaun-]

Sounds like you hit the nail on the head!

Everything rusty and falling apart, but somehow still working. Looks like someone used a random selection of parts they found in the back of their van to bodge it together.

Concerns me a bit that there are NICEIC stickers on some of the work.

Yeah ideally I’d have liked the same, was looking forward to making it all neat really but he wasn’t having any of it ha. Think it’s like a different language to them most of the time anyways.

Thanks, I think I’ll just make a note of the recommendation on the cert and then at least it’s covered.