Just doing a periodic on some offices, and each office has a small mains unit fed with a piece of 16mm t&e, they are relying on the 6mm earth in the cable for the main earth. Now they are only a few sockets and lights in each office, no bonding needed or anything and if you do the aidiabatic equation the size is well in but I'm not 100% sure whether to code it on the report or not. There are individual isolators for each submain and these are fed with 25/16 earth tails so that covers the main earth cable size. This is the distibution area by the way, the real problem is the whole lot is fed from a single 100A supply, this wouldn't be too bad but there is a chip shop wired off it as well. Cut out too hot to touch pulling 75+ amps.
Can't see anything wrong with the T&E earth. You say that the cut out is too hot to touch even though it is 100A and only pulling 75A. I would attempt to verify that it is a 100A supply.
Not the best picture. Thought it was 3 phase at first glance, lead incoming cable with 100A fuse, the other two are unused but look like they are connected with a bus bar through them, I suppose the load could be split between them but you would still have a single neutral return and obviously the same load is still on the lead cable. Earth connection is **** as well. Meant to add, its probably my clamp meter that inaccurate, although the live is warmer than neutral so possibly bad connection.
It can't be as this varies based upon a number of factors which require calculation, so is different for every installation. T&E is essentially designed to be used with domestic installations only. That said, if we are being told that the cpc size does satisfy the adiabatic equation then I can't see why we are being asked if the cpc size is adequate. Surely he has answered his own question.
Never relied on the 16mm t + e cpc when we did conversions. I always ran a separate 10mm green/yellow to each flats earth marshall from intake position. All labelled accordingly.
If the cut-out is "too hot to touch" does that not raise any alarm bells? Like a potential fire? All that f lot on one cut out? I would say that far exceeds the concern over a bloody cpc wouldn't you?
Its a report not a fix it, I have to mention everything and I'm pretty sure I already know the answer to the hot fuse.
You shouldn't, but you see all kinds of crazy things these days. The OP did tell us that these were offices - not a domestic installation. But the adequacy of the cpc can only be confirmed by calculation, which the OP tells us he has done. So I don't understand why he thinks an observation would be justified on a report when he has confirmed that the cpc is of an adequate csa.
I would not use Twin and skin on any Industrial install, see it loads of times tie wrapped to tray etc.
Now I never said I would use it. You have both made claims it is designed for domestic only. Can you back this up as I have never heard this before?
Twin and skin sheath does not have the same mechanical protection as say SWA or conduit etc. so its not best suited to industrial works
Ahhh but you never said that did you. You agreed with Risteard that it is 'not designed for industrial use'. If this statement is true then in the ops case cable is being used against manufacturers guidance which is a reg break and should be coded. Of course, however T&E is not specifically designed for any particular sector so that statement is rubbish.