2 fuse boxes one mains meter

[AndyPRK]

If it were me I would install a 50A MCB in the downstairs CU (on the non RCD side) to connect to the loft.

Nice and tidy downstairs.
One isolation switch turns everything off.

 

[freyster]

Hi Chri5

Thanks for the last message, that was easy enought to understand and makes total sense. You spot on with the 12m SWA cable.

Can you recommend what 60/65 amp fuse I should by and what type. Ive done a quick google and havent come up with much.

Also with the Henley block is it best to go with the Single Pole or Double pole box.


I did think about AndyPRKs last comment, as I have a 15 way or will have a 15way CU downstairs, I do have the space to plug in another fuse rated at 50. I know this is the easiest/ simpliest way of sorting the issue out but in terms of the best solution what would you sparkys suggest?

 

[Taylortwocities]

Wylex 60A switchfuse

Henley block, its up to you. I prefer the double ones but depends a bit on how the tails are/will be configured.

 

[Chri5]

I'd pump for the separate connections, so the cu's are independent. Thus it keeps the two installations separate and a failure at one cu won't effect the other.

On T2C's post there's an option for a metal clad s/fuse- that would allow the swa to gland on to the switch fuse case direct, rather than via a intermediate metal box- it would keep the installation tidier.

 

[Taylortwocities]

You are correct the metal one is HERE

Do not use a metal one if your supply is TT!

 

[ban-all-sheds]

Wanted some advice being a newbie on this forum as well as a newish electricain.

Define "electrician"....

Freyster - I'm not labouring this to score points, or to make you feel small, but looking at some of the questions you're asking they are pretty basic. Nobody is born knowing it - it all has to be learned, but you do have a professional responsibility, a duty of care etc to your customers.

Of course everyone has questions from time to time, and of course nobody knows it all, and of course there are always new things to learn, but when people give you a job to do they expect you to know how to do it, and how to design it properly, and what materials and accessories to use etc, and they don't expect you to be using them to practice on.

Do you honestly, hand-on-heart, think that you really should be presenting yourself as an electrician to them just yet?

 

[freyster]

Hi Ban-All-Sheds

Yes your right and I would absolutely do that in all circumstances. I only do jobs what I'm comfortable with and know I can do it.

In regards to the 2 Consumer units, its the first time I've come across this scenario and secondly its my own house I'm actually doing this ;o) hence I'm coming back to you guys/ pros for advise on what the best solution is.

Atleast if I've tested it in my own house, I will feel comfortable in taking a job on with similar requirements.

-------------------------------------------

In regards to the last comment

"Do not use a metal one if your supply is TT!" what is TT? (apologises, new to the forum and terminology)


Chri5

Thats right, I was looking to have the following (Is that what you mean by pump for seperate connections?


Meter - 25mm tail to Henley block - 25mm tail to Ground CU and 25mm to 60amp Switch Fuse - 16mm tail (SWA)

 

[Taylortwocities]

In regards to the last comment

"Do not use a metal one if your supply is TT!" what is TT? (apologises, new to the forum and terminology)

If you do not know what TT is then you should definately NOT be doing this, or any other electrical work. It is the very very first thing that you must check when doing and electrical works.

What qualifiactions do you have?

I cannot help you any more as you ahve a good chance of damaging yourself and/or your customers.

 

[freyster]

Hi

Sorry, maybe I worte that slightly wrong. I understand the concept of earthing and the various different concepts in the earthing network such as the TT, TN etc. But the issuse which baffles me, correct me if Im wrong, I thought the TT required a RCD protection. But the RCD protection will be on the consumer end where as the SWA cable will be connecting into the Switch fuse

The other dilemma I have, the consumer unit in the loft is a plastic casing so terminating the SWA cable cannot be done via the gland system as there is no method of security the round gland, just a cut out at the back of the box.

 

[Chri5]

Re: your last question to me, answer = yes !

A TT system would have a earth rod as the primary earthing for the property.

A TT system (tends) have 100 amp / 100 mA rcd at the front end- domestic rcds on boards tend to be 30 mA. It is possible to have a TT system with rcds at cu and main supply. As I'd hope you appreciate a 30 mA would trip 1st meaning that only part of the site would trip (discrimination)!

Has the swa got 2 core or 3 core ? Are you intending to use the swa armour as the earth for the CU in loft or do you intend to use (if 3 core) one of the swa cores ?

The swa armour must be earthed otherwise you negate the whole reason for providing the swa in the 1st place.

At the loft CU you need to have a box to gland off the swa.

I take it that the following mean something to you ?

Please be safe, and please note that I'm now hesitant about giving you info due to your (seemingly) lack of knowledge on very basic elements of our work.

Out of interest how do you intend to get this work through Part P notification ?

 

[bongos]

In regards to the last comment

"Do not use a metal one if your supply is TT!" what is TT? (apologises, new to the forum and terminology)

Terra Terra.

One of the earthing arrangements.

 

[freyster]

LoL

I do understand where you guys are coming from. Its all new to me, esp the 2 consumer set up which is slightly mind boggling if you havent done this before.

Chri5

Yeah I do understand you and the pics provided, I totaly get that.

In regards to the earthing, I dont have an earth rod, my earth is supplied by the supplier which is the TN-C-S set up so going for the metal switch OK.

Also I do apologise if I sound dumbish, but all this terminology, new experience etc etc is taking time to understand, esp when loads of people advising all sorts.

Hence why I came to this forum to find out what the best solution