16mm T+E for Loft Extension, (en- suit shower. )

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sparkyjohn1

16mm sub main.jpg

Just wondering if any sparks out there would have any obligations or concerns about a proposed installation for loft conversion,, ( see drawing for details..)..
Hear loads of conflicting theories about cable sizing for showers , some of them are borderline at best... and different installation methods etc... this is my proposed method, might seem a bit overkill.. but seems to tick every box regarding cable sizing , length of run,,, installation method ( in trunking..).. and diversity.. I'd rather be well clear of borderline to be honest...
Quite a big House.. concerns with the run to the opposite corner for feeding the shower... Didn't really fancy terminating two lots of 16mm in a shower pull cord switch to be honest,,, 10mm can be a nuisance at times,, I hope this method would satisfy every criteria..??
 
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plus- gives ample scope for upgrades of showers in the future if you use 10mm,,
I have never used 6mm for a shower ,, EVER,,,, asking for trouble...
 
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there's thousands of showers out there asking for trouble then. 9.5kW = 40A. 6mm ccc is 47A. what's the problem?
 
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Mate, I've seen Fire Damage caused by Electrical faults . and it aint a pretty sight, believe me,,!! Maybe its just personal preference,, I always use 10mm,, for showers, and Induction Hobs for that matter,, rather be too safe,, than have it on your conscience if anything ever happened.....
Yeah, the regs. state these values, per installation methods,, but people really push it to the boundaries sometimes,,, Just what i'd rather do,,, and walk away knowing that there is enough parameters in place should anything ever happen... Personal preference, i guess.. nothing against you mate
 
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sparkyjohn1 said:
Mate, I've seen Fire Damage caused by Electrical faults . and it aint a pretty sight, believe me,,!! Maybe its just personal preference,, I always use 10mm,, for showers, and Induction Hobs for that matter,, rather be too safe,, than have it on your conscience if anything ever happened.....
Yeah, the regs. state these values, per installation methods,, but people really push it to the boundaries sometimes,,, Just what i'd rather do,,, and walk away knowing that there is enough parameters in place should anything ever happen... Personal preference, i guess.. nothing against you mate
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It is nearly always down to poor terminations not 6mm cable.
 
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There's no such thing as "pushing the boundaries" in a compliant circuit. Either a cable can carry that amount of current or it can't. I think you will find that stated values err on the conservative side too. I have seen showers fed in 2.5mm cable that have not caught fire.
I always sleep easy as I do my calcs and install to them.
Not sure where your lack of confidence in calcs stems from, but hey, if you like overspeccing that's your preference, nothing against you either.
I have never installed more than a 6mm to any cooker or hob, and only last week saw a new induction hob with a 13A plug top as supplied.
 
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think its just a phobia of fire , combined with seeing it first hand in a fire damaged property.. I'd hate to stand up in court to defend myself if it proved fatal that is was Electrical fire damage caused by inadequate cable selection,, plus, what about if you installed clipped direct method, 6mm as most people are saying, then someone comes along and over- zealous-ly insulates the loft,, ? causing insulation to touch the cable for more than 500mm,?? would this make the electrical installation null and void..? due to the additional insulation that has been added??
 
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Andy78 said:
saw a new induction hob with a 13A plug top as supplied.
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Owing to power sharing technology. When you boost one induction zone it will take power from another. I have an induction hob - not one of the 13A ones, but I have it on a 32A cooker circuit with an oven too. Don't get the obsession with running them on their own circuit all the time!
 
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sparkyjohn1 said:
think its just a phobia of fire , combined with seeing it first hand in a fire damaged property.. I'd hate to stand up in court to defend myself if it proved fatal that is was electrical fire damage caused by inadequate cable selection,, plus, what about if you installed clipped direct method, 6mm as most people are saying, then someone comes along and over- zealous-ly insulates the loft,, ? Causing insulation to touch the cable for more than 500mm,?? Would this make the electrical installation null and void..? Due to the additional insulation that has been added??
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then it's time these insulation monkeys learnt not to smother cables with their itchy poo snot, or gain useful employment in a call centre.
 
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Listen guys,,, I just like over -compensating,,, there's no harm in that,,,!! I don't really see a problem, and i aint making it it massive argument.. I know every cable I install is protected accordingly back suitable M.C.B back at C/U. No harm in that... I aint entering realms of 'what ifs.." and all that,,,,,, Its just personal preference.. All I asked did anyone have any objections,, seems like I'm taking the brunt of mild abuse.,, for being too safe!!
 
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sparkyjohn1 said:
think its just a phobia of fire , combined with seeing it first hand in a fire damaged property.. I'd hate to stand up in court to defend myself if it proved fatal that is was Electrical fire damage caused by inadequate cable selection,, plus, what about if you installed clipped direct method, 6mm as most people are saying, then someone comes along and over- zealous-ly insulates the loft,, ? causing insulation to touch the cable for more than 500mm,?? would this make the electrical installation null and void..? due to the additional insulation that has been added??
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That's what your calcs are for. I trust them as I know they have a small margin of error built into them. I also know from experience that appliances don't always pull what they state, and that cable can take more than it is rated at.
As long as your calcs are correct you have them to back you up.

I know what you mean about insulation being laid after your cable, but you can future proof your install. Clip it up and out of the way, provide a duct for it, all sorts you can do. Do you run 16mm to larger showers just in case ?
 
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If someone comes in after and covers it in insulation, you have an installation certificate tha proves the date you fitted it, and the home owner will have a certificate of compliance for the insulation, again with a date on it.

What happens when you have gone is not your problem, so long as your work is safe and complies etc.
 
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sparkyjohn1 said:
listen guys,,, i just like over -compensating,,, there's no harm in that,,,!! I don't really see a problem, and i aint making it it massive argument.. I know every cable i install is protected accordingly back suitable m.c.b back at c/u. No harm in that... I aint entering realms of 'what ifs.." and all that,,,,,, its just personal preference.. All i asked did anyone have any objections,, seems like i'm taking the brunt of mild abuse.,, for being too safe!!
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not abuse, mate. Just friendly discussion. No issues with your methods. Better safe than sorry, ok, but still think it's overkill.
 
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Never installed 16mm for a shower mate.. lol !! Only Sub Mains,, Out-houses, Summer Houses etc.. (dependant on load.. ! ).. although found it quite appropriate to feed a chandelier once , on a 2.5 mm T+E on its own 16 amp M.C.B, 32 bulbs tho... !! lol
 
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anyway why the hell would you have 16in and out anyway?

even if its smothered then you can get away with 16mm+ to pull cord then 10mm to shower.

besides clamp the shower and I doubt it will pull rated current.

most people never had shower on max setting and it would take a long time for cable to heat up if it was undersized.

when people used to bypass there meters do you think they used 16/25mm of course they would probanly use flex or 2.5 or something easy to get
 
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Never in a million years mate..!!! correction factors , diversity, installation method aside,,, NEVER A 6 mm surely?? And NEVER 50 Amp M.C.B for 6mm either..!!!! No chance bud...
 
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shanky887614 said:
most people never had shower on max setting and it would take a long time for cable to heat up if it was undersized.

get
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The temperature settings on them change the flow rate of the water not the power it uses.
The only control of power is selecting one or two elements, the general idea is that the two element setting is for normal situations and the one element setting for low water pressure.
 
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Plus Ambient Temperature,, -- Cable ran in a loft, full of insulation,,, Middle of Summer,,, South East coast of England,,, Man, the temperatures are sweltering,,,, gotta be 100 degrees plus...!!!
 
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sparkyjohn1 said:
Personally I would never protect a 6mm on a 50 Amp M.C.B . 40 Amp MAX...!! Over compensation,, I don't trust diversity

Mr Safe,, .
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It's got nothing to do with diversity mate. A shower is a single item of current using equipment with a fixed load. No diversity applicable.

This is about the relationship between I[SUB]b[/SUB] and I[SUB]z[/SUB], and in this situation, I[SUB]n[/SUB] doesn't come in to it other than selecting an appropriate method of short circuit protection (I[SUB]a[/SUB]). Think about it :)

sparkyjohn1 said:
Plus Ambient Temperature,, -- Cable ran in a loft, full of insulation,,, Middle of Summer,,, South East coast of England,,, Man, the temperatures are sweltering,,,, gotta be 100 degrees plus...!!!
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I said correction factors allowing.
 
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shanky887614 said:
anyway why the hell would you have 16in and out anyway?

even if its smothered then you can get away with 16mm+ to pull cord then 10mm to shower.

besides clamp the shower and I doubt it will pull rated current.

most people never had shower on max setting and it would take a long time for cable to heat up if it was undersized.

when people used to bypass there meters do you think they used 16/25mm of course they would probanly use flex or 2.5 or something easy to get
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I'd put a mixer in for the shower ............save getting mixed up with the cable sizes. Either that or it'd be bleedin' tight in that pull switch.:smile5:
 
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sparkyjohn1 said:
Personally I would never protect a 6mm on a 50 Amp M.C.B . 40 Amp MAX...!! Over compensation,, I don't trust diversity

Mr Safe,, .
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Diversity is irrelevant to the point!

The question is why would you not protect a 6mm with a 50A mcb if the rating factors permit for the Ib?

You are not coming across as being mr safe here, all you appear to be doing is wasting your customers money on unnecessarily oversized cables.
 
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Listen, bud,, I'd Rather Do a full Install on a property.. safe in the knowledge that every cable is more than sufficient for the job in hand..... You can't fault me for that,,, I will include the plans for the job the next message. (proper estate agent drawings.....)... Heck,, I've installed many a dual consumer unit,,, one for lighting,, one for everything else,,, 4 R.C.D's in total,,, Big Houses down here in Kent,,, not a 2 up 2 down property...!!.. Please don't patronise me,,
 
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sparkyjohn1 said:
Listen, bud,, I'd Rather Do a full Install on a property.. safe in the knowledge that every cable is more than sufficient for the job in hand..... You can't fault me for that,,, I will include the plans for the job the next message. (proper estate agent drawings.....)... Heck,, I've installed many a dual consumer unit,,, one for lighting,, one for everything else,,, 4 R.C.D's in total,,, Big Houses down here in Kent,,, not a 2 up 2 down property...!!.. Please don't patronise me,,
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Who was that directed at? Me or Dave? I'm not being patronising, I hope :)


sparkyjohn1 said:
safe in the knowledge that every cable is more than sufficient for the job in hand
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Shower pulls 45A, cable is good for 47A. Ergo sum: cable is more than sufficient for the job in hand :)
 
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16mm T+E for Loft Extension, (en- suit shower. )
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