9.5 kw shower on 6mm ?

[jonthesparks]

just been to a job , saw that the shower 9.5 kw is on 6mm t&e the cable goes in the wall and under floor boards ,No insulation, to the board (A cable run of no more than 10 m) . I said downgrade the shower to 8.5 max. Is it really necessary ? never quite sure , its borderline to me .

 

[sedgy34]

wow!! whos gonna last longer this thread or our forum dinosaurs? lol no insults intended the love on here is awesome

 

[steveberry11]

Ib = 41.3 A then In 45A so use a B45 mcb then It from Table 4D5 6mm Ref C = 47A So

Regs state Ib less than or = to In and In less than or = to It

Conclusion 6mm Ref C = 47A use a B45 Breaker and 9.5Kw shower at nominal current 41.3A everything OK

Don't forget all those correction factors that need to de applied to the tables you have refured to.

 

[wade88]

i think a lot can be said for a bucket with a few holes punched through hung on a pole huh.

 

[steveberry11]

i think a lot can be said for a bucket with a few holes punched through hung on a pole huh.

Z


What size bucket ( oh no here we go again)

 

[Engineer54]

The most I seen engineer is a meagre 3 630awa's per phase, and I thought that was a lot lol!

Try 19 X 95mm per phase+N run Trefoil + N on tray for around 150m and more from TX to Main Switchboard, via Stand-by Genny changeover switchboard... There were 6 TX's supplying that building, all with similar numbers of supply parallel feeders...

TX's were mainly 127/220V, (Malcolm will recognise that voltage band instantly!! lol!!) with a couple of 220/380 TX's supplying the bigger equipment...

 

[platty1005]

that's fine, platty, until the insulation muppets arrive and reduce your ccc to 27A.

First post says NO INSULATION so i was just answering the original question and stated that 6mm is ok for REf C

If REF method 101 then 16mm cable is just big enough but i would not like to wrestle it into a pull switch !!

 

[telectrix]

i totally agree with you. we design a circuit to comply under existing conditions. if these itchysnot installers don't know any better than to smother cables, then they should get fresh employment selling the big issue.

 

[sedgy34]

i totally agree with you. we design a circuit to comply under existing conditions. if these itchysnot installers don't know any better than to smother cables, then they should get fresh employment selling the big issue.

Tel, the insulation installers is monkey see monkey do they don't know about all the Calcs to do with cables etc they just fill the area with the stuff off the van and move on to the next job.
its us poor guys who have to think of all that derating factors etc

 

[Geordie Spark]

in his towel

Why would he have an MCB in a towel ?

 

[sedgy34]

Why would he have an MCB in a towel ?

you have some posts to catchup on fella

 

[Litttle Shonet]

Just or all the posts about insulation (itchy Snot, I think some of you call them). You can't future proof for every eventuallity. If you did, then you may as well put cabling in from the roof just in case customer wants PV later on.

 

[Guitarist]

Just or all the posts about insulation (itchy Snot, I think some of you call them). You can't future proof for every eventuallity. If you did, then you may as well put cabling in from the roof just in case customer wants PV later on.

Totally agree mate. If the loft has only 4" of insulation tho, it is very likely that at some point in the foreseeable future there will be some addition. I always take my oval conduit 6 inches above existing insulation for just such an eventuality

 

[Geordie Spark]

Totally agree mate. If the loft has only 4" of insulation tho, it is very likely that at some point in the foreseeable future there will be some addition. I always take my oval conduit 6 inches above existing insulation for just such an eventuality

Good thinkin' bonny lad .. are ye a Geordie by any chance?? ....... If yer not, divven't worry ... aahl make ye an honourary one for noo.

 

[stevothespark]

Havnt bothered to read the other pages so this may have been said. 6mm will do for a while, id never put a 6mm cable in for anythin over 8.5kw shower, simply because ive been to far too many homes where a 9.5kw has been on an 6mm and the cable is burnt out/switch etc. Over a period of time, the 6mm will begin to melt, usually from the women who spend an eternity in the shower ! 10mm everytime for showers over 8.5kw every time.

 

[Moses]

Tel, the insulation installers is monkey see monkey do they don't know about all the Calcs to do with cables etc they just fill the area with the stuff off the van and move on to the next job.
its us poor guys who have to think of all that derating factors etc

I think that we must recommend that all new circuits installed in lofts that have no loft insulation, should be installed, at least 300mm above the plasterboard, on the loft wall or along appropriate battens installed for the purpose.

This would circumvent the "monkeys".

 

[Geordie Spark]

I think that we must recommend that all new circuits installed in lofts that have no loft insulation, should be installed, at least 300mm above the plasterboard, on the loft wall or along appropriate battens installed for the purpose.

This would circumvent the "monkeys".

The good folks of Hartlepool knew how to deal with monkeys.

 

[Dan]

I'm just bumping some threads in the Electrical Forum, don't mind me while I do this, you don't have to respond to them. Although if they are still current topics, and you do wish to reply, you're welcome to. Keep the thread on-topic and make sure you stick to the forum rules though.

 

[Gnasher]

Only one answer to this. Carry out the full design process to determine the answer.

Just remember.

9.5 KW = 41A so the protective device must be 45A or 50A depending on CU. take into account the following down rating factors for starters.
Grouping factors
Insulation
Installation method.

6mm has never been big enough for 9.5 KW so can not be classed as does not comply with current regulations.
If it trips regularly there is an issue that must be addressed. The fact that it is only used for a short time is not the correct approach.
This is a C2 fault potentially dangerous.

 

[Megavolt]

6mm on a 32a Mcb all day long

Tin hat on