Is This Ok?

[Nicky Tesla]

In any T&E cable, the cpc will always be one size under the main conductors. eg: 6.0t&e with a 4.0mm cpc. The only exception to this is 1.0mm t&e where the cpc is also 1.0mm

wrong...........6mm = 2.5mm also 10mm+4mm cpc

oh wow.....your not an expert any more well done :Salute (im talking about his signature paragraph on his posts)

 

[SLIPSHOD & SLAPDASH]

In any T&E cable, the cpc will always be one size under the main conductors. eg: 6.0t&e with a 4.0mm cpc. The only exception to this is 1.0mm t&e where the cpc is also 1.0mm

Thats not correct

 

[steptoe]

2.5 with 1mm cpc

What size cpc does 16mm t&e have in the UK normally?

 

[Steve3948]

Gazza I think you have been reading the wrong book

 

[Andy™]

What is the 4.0mm that's been mentioned ?

my mistake, for some reason i thought he had 10mm T&E, with 4mm earth. not 6mm T&E, with 2.5mm earth.

 

[Nicky Tesla]

This sounds to me like a standard shower protection unit (RCBO) or a one way RCD board with mcb. Either way in my view this is a second consumer unit and should be treated as such. It should not be feed from the first C/U's main switch. It could be feed from an mcb from the first board but not ideal.

If it were me I would re feed the shower protection unit from a henley block

idealy it would be on a whole new DB. it could also be fed from an MCB if they were still available.

A seperate rcd+mcb enclosure is common practice , fed from the main DB,

 

[Barx]

If the 6mm Tw& e

What about rcd protection if the cable is less than 50mm deep.

Also 6mm tw&e can sometimes have a 2.5mmm cpc.

That's what I'm saying. Its not OK because of lack of protection. And yes 6mm has 2.5mm cpc. Only ever seen it with with 2.5mm cpc. Just to clarify, I'm saying install is wrong. Lol

 

[Nicky Tesla]

That's what I'm saying. Its not OK because of lack of protection. And yes 6mm has 2.5mm cpc. Only ever seen it with with 2.5mm cpc. Just to clarify, I'm saying install is wrong. Lol

Seems you missed it the first time so i will repeat it

it is more than 50mm deep it is in the cavity of a plasterboard wall which is where the tails to the main switch comes from as well so no henly block connection for this.

Just saying it is wrong does not make it so. Can you tell me why you think it is because im not convinced so far

 

[Steve3948]

Looped supply, short length of cable probably less than 300mm, what is different to this than having a 200A bus-bar chamber with 6mm feeding 20A Switch-fuse for alarm supply.

 

[Nicky Tesla]

Looped supply, short length of cable probably less than 300mm, what is different to this than having a 200A bus-bar chamber with 6mm feeding 20A Switch-fuse for alarm supply.

HHMMMMMM yes i see, well seems ok then ....great :B-

 

[Sidewinder]

It is adequately protected against overload by the over current protective device within the enclosure with the RCD?

 

[Sidewinder]

Jumping the gun again boatyard!

 

[Barx]

Seems you missed it the first time so i will repeat it

it is more than 50mm deep it is in the cavity of a plasterboard wall which is where the tails to the main switch comes from as well so no henly block connection for this.

Just saying it is wrong does not make it so. Can you tell me why you think it is because im not convinced so far

OK, forget I even joined in in this thread as I am obviously wrong. Which is fine, I don't mind holding my hands up when I'm wrong and I still have a good bit to learn in life.

For the sake of it, the reasons I said I thought it was wrong are:

• 6mm twin protected by just the supply fuse (which is likely to be at least 60A)
  
• The twin is piggy backed from the main Isolator
  
• If the cable goes into the wall, how do you know it is >50mm deep and if it is 50mm deep, is it 50mm from the other side too as a standard CLS stud is 75mm thick. So if it's 50mm from one side, it is only 25mm from other. Obviously construction types can differ.
  

I'm no time served, qualified up to the back-nines spark so like I said, could well be wrong. I guess I play on the side of caution and would never do this personally. I tend to install to a standard that is NOT questionable.

 

[Nicky Tesla]

"I tend to install to a standard that is NOT questionable."

if you know the answers to the question then it is only questionable by those who dont know the answer

thats what forums are for, to find the answers.

"OK, forget I even joined in in this thread as I am obviously wrong."

dont get upset..........i was just waiting for the answer i didn't have an answer for........thats how you get to a conclusion.

 

[Barx]

Kiss and a hug then?

 

[Badger]

id say its wrong because if the 6mm from the main switch became loose and started to melt/short to the neutral the 6mm cable size cannoit take 60-80-100 amp depending on the main fuse.

 

[Steve3948]

Badger you are not supposed to connect it up loose, what would the PSC be, probably not 60-80-100, what the logical chance of the short.