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

[sparkyjohn1]

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..??

 

[telectrix]

way overkill. 10mm from CU1 to CU2. 6mm shower. rest OK.

 

[sparkyjohn1]

Not liking the 6mm T+E for Electric Shower bud... regard of the length....

 

[telectrix]

6mm is good for up to 9.5kW up to 20m run, as long as not run in insulation.

 

[sparkyjohn1]

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...

 

[uksparks]

Not liking the 6mm T+E for Electric Shower bud... regard of the length....

For what reason don't you like it? It's perfectly adequate and acceptable.

 

[uksparks]

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...

Why is it asking for trouble? I agree to an extent about future upgrades...

 

[telectrix]

there's thousands of showers out there asking for trouble then. 9.5kW = 40A. 6mm ccc is 47A. what's the problem?

 

[Andy78]

Crikey, I can't imagine working with 10mm in every shower pull I fit. Every 8.5kW shower I have ever fitted has had 6mm supplying it.

 

[sparkyjohn1]

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

 

[Meggerman]

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

It is nearly always down to poor terminations not 6mm cable.

 

[Andy78]

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.

 

[snowhead]

4mm For RFC then?

 

[sparkyjohn1]

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??

 

[Risteard]

saw a new induction hob with a 13A plug top as supplied.

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!

 

[Risteard]

then someone comes along and over- zealous-ly insulates the loft,, ? causing insulation to touch the cable for more than 500mm,??

Not likely to be covered on all sides by insulation if it's clipped surely.

 

[telectrix]

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??

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.

 

[sparkyjohn1]

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!!

 

[Andy78]

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??

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 ?

 

[uksparks]

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.