Rewiring for a 10.8kW shower

[skenk]

I think it's pretty clear who is spouting nonsense on this thread and it's not me or JohnW2. Until you can actually back up your arguments there's no point in trying to respond to your points. As usual, when someone picks you up on something or your argument is plain wrong you just ignore it or resort to personal insults

 

[holmslaw]

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[skenk]

Yes the MICC could be glanded into an enclosure but we're taking about a supply to the meter here which is 50+ yrs old. I for one am not going to be messing with it

You think I am poorly trained, inexperienced and irresponsible but just earlier today you claimed "I don't give opinions". You know practically nothing about me but you seem happy try and attack me to defend the fact that you are wrong in your answers on this thread. The OP asked a question - what's the biggest shower I can have with this cable and I gave the answer 9.6kw may be ok, and explained, briefly, why. All you have done since is claim this is incorrect and attack me so please show me where I am wrong. I am assuming method C (free air/clipped direct/plastered wall) and the unajusted figure is 46A. I said it may be possible, knowing that every 9.6kw shower I have seen is rated at 240v, and having installed such circuits using method C throughout. You said: "the 6mm cable will have a maximum rating of about 35A". I was right and you were wrong and you've been having a hissy fit ever since. Now you might not like that because every time you come across a 6mm shower circuit you insist on replacing it but the fact is that in many cases a 6mm shower circuit is adequate to be upgraded to 9.5 or 9.6kw shower (at 240v).

There's 2 threads on here just now where I was asking for help, if you look through my posts you will see I have admitted I was wrong before, so your assertion that "[you] seem to think you know it all" is rubbish.

You on the other hand, despite all your 'experience' have gotten it wrong on many occasions and never (I have never seen it) admit you were wrong even though every single other contributor on a thread disagrees with you.

The light fitting was in what is basically a shed with some cans of paint and solvents. I've left it no less safe than before (which s very safe IMO). You still haven't put up any reasonable argument why I shouldn't have done what I did, if you really cared for my clients you should at least try and help instead of just sneering and bashing. I suppose you were born experienced?

Can't believe I've had to look up the brb and take half an hour of my time to answer your bull***t

 

[holmslaw]

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[ricicle]

Holmslaw can you explain how you came about rating the 6mm² at 35A without knowing the exact install method ?

 

[JohnW2]

I am assuming method C (free air/clipped direct/plastered wall) and the unajusted figure is 46A.

I know exactly what you assumed. Must admit I am unfamiliar with your description of ref method C, my BRB just says clipped direct can't see anything about free air. If it did say free air then you assumption would be correct, but it doesn't, thats why the 46A rating cannot be applied.

You must have the same BRB as everyone else. Ref Method C includes not only Installation Method 20 ('clipped direct') but also (amongst other methods) Installation Methods 57 & 58 (in masonry, which includes plaster).

As for 'free air', that's a bit more complicated. Most people do seem to think in terms of Method C including 'in free air', but I don't think that's strictly correct. Installation in free air is Method E or F. However, since that invariably means a greater CCC than Method C, it means that, in practice, a cable which has a mixture of 'clipped direct', 'in plaster' an 'in free air' (which is the most common situation in residential installations) will have a CCC as indicated in Table 4D2A for Method C. I guess that's why people usually think as if 'in free air' were part of the Method C definition, since that results in the right answer for the common mixed-methods installation.

Taking the example of the 6mm² cable you're talking about, if it has a mixture of those three installation methods, the CCC per Table 4D2A would be 46A. If it were entirely in free air (Method E), it would have been (again per Table 4D2A) 51A.

Kind Regards, John.

 

[skenk]

Fine holmslaw, once again I will admit I made an error, scratch the words 'free air' - As John pointed out free air is not going to noticeably lower the CCC, and certainly not by 24% - but I'll give you that. A 6mm CABLE INSTALLED CLIPPED DIRECT AND IN A PLASTERED WALL HAS A CCC OF 46A (unadjusted) There are PLENTY of installations like that around here. Now when will you admit you are wrong?

[never]

Thought not.

 

[holmslaw]

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[holmslaw]

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[holmslaw]

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[JohnW2]

Also Mrwaffle has now managed to get 6mm rated at 51A, by using the wrong table.

In what sense did I use the wrong Table? What I said was that if (which it obviously isn't) the cable were entirely in free air, then per Table 4D2A, Reference method E ("in free air OR on a perforated cable tray etc., horizontal or vertical") indicates that it would have a CCC of 51A.

I'm as fallable as anyone else - so, if you think I've used the wrong table, or ended up with the wrong figure, I'd be very grateful if you could explain what I have done wrong.

Kind Regards, John.

 

[ricicle]

Holmslaw - why are you blantantly saying that the horizontal cable is not clipped, the cable could have been clipped along the joist.

 

[holmslaw]

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[ricicle]

All evidence points to the cable being laid in the floor void and therefore will not be clipped direct.

What evidence ?

 

[JohnW2]

All evidence points to the cable being laid in the floor void and therefore will not be clipped direct.

What evidence ?

I guess that (s)he is referring to the op's plan to use the existing cable to pull through a new one. That suggests that the op thinks/knows that the present cable is not clipped, and the new one (if by some miracle it got pulled through) would certainly not be.

What intrigues me is where the 35A figure came from. Even if the installation were Method B, the tabulated CCC of a 6mm² cable would appear to be 38A.

Kind Regards, John.