Help needed. Garage wiring

[Afoster615]

Hi all, new to this forum, from northern ireland an keen to learn the art of electrical installation and theorys. But for now i need some help. Bought a house a couple weeks back, with 4 outhouses and a shed, that are wired up by what looks like a man that didnt have a clue. So i have my main 12 way CU which is wired to a 3 way switch box with old ceramic fuses in a spare room in the house by a 32amp mcb from the main CU. its covering 3 sockets in the kitchen and then wired to another old 3 way switch box / CU in the shed which has a couple sockets & lights wired to it (WHICH DO NOT CURRENTLY WORK) worked until last week then bang. Im planning on stripping this whole system and adding a 6way consumer unit into the spare room, via the 32amp mcb thats already been wired to the switch box,( reason im using 6 way is because ive got one new for free) then running 4mm amoured cable into the sheds to a new 3 way CU and wiring up 4 sockets + 3 lights. In my head it sounds fine, but i know its not the case so please someone who was mad enough to read this, enlighting me on this matter of what i can do. Thanks

 

[Afoster615]

Might i add, im not convinced wiring from 32amp mcb from main CU to 100amp main switch in sub CU is safe & useable, although it was previously done an is the way it sits.

 

[shaun1]

Hi,

Some questions....
What is the earthing arangement to the house?
Is the 32A Circuit you plan to use RCD protected?
Are there any RCDs in your new 6 way board?
Is your new board ammendment 3 complient (not sure if this applies to northern ireland but a metal enclosure with make the armoured terminations easier)
What equipment are you intending to supply in the sheds/garages?
Is the supply to the kitchen the only circuit in the kitchen?

 

[Afoster615]

Thanks for your reply. Not sure what the earthing arrangement is,
yes the 32amp circuit is protected with an rcd. 1 rcd in the new 6way board.
An both new CU are in compliance with the current regs.
Would only be running my 230v 150amp welder and some light use powertools. Grinder etc. No the kitchen is mostly wired from main CU there is just 3 sockets wired by the switch box.

 

[Octopus]

Dare I suggest you get "on the ground" advice from a local spark?

Without a site visit its almost impossible to advise

 

[Afoster615]

The only thing im not sure about is the connection from the main CU to the new Sub CU. 32amp mcb 6mm t&e to a 100amp main switch. Or can i do without the main switch an wire directly to the 63a rcd. There is only 2 circuits on the sub CU.

 

[Octopus]

Its not just about what you think ....

Do you have any test kit?

 

[Afoster615]

i will not be making the final connection, i will be wiring up the shed an pulling the swa into the house to be ready for the final connection. Im just after some education for now regarding the connection from the main CU to the sub CU.

 

[Octopus]

As I said, theres more to this than meets the eye, or DIY sites who often give out misleading advice

You seem determined on the bang test ......................

 

[Afoster615]

Im well aware of that. An in my eyes its a pretty simple job, its basically just doing the exact same job thats currently there, an has been for 20 years. Only difference is im looking to strip it all an use correct equipment + changing the 2 old boxes thats there.
Ill just add this in again.
I WILL NOT BE MAKING THE FINAL CONNECTION AND IT WILL BE INSPECTED AND TESTED BY A ELECTRICIAN.

 

[casperLennon]

Ask your electrician then.

 

[DavidSpark]

Hopefully I don't cause disrespect to you in any, however I believe what some have tried to say is that although you may just be replacing what is already there, what was already there might not have had any thought behind it.

Good design requires background information and knowledge of the current electrical installation.

Earthing arrangement
Is it suitable for exporting to various sites around your property and have you considered the possibility that you may need to install earth rods and such to comply with certain requirements of BS 7671.

Cable sizes
How have you determined the correct size of conductor to supply these out houses, have you taken the de-rating factors of the cable into account?

Ill just add this in again.
I WILL NOT BE MAKING THE FINAL CONNECTION AND IT WILL BE INSPECTED AND TESTED BY A ELECTRICIAN.

I am inclined to think that this statement is not true. However on the off chance it is, as you are wishing to learn the art of electrical installation and theory, perhaps you could get in contact with a local electrician and have them talk you through what you require and the reasons behind the choices before work begins. It'll go a long way in teaching you what you wish to know.

 

[Afoster615]

Umm, i know what the problem is, you 2 “qualified electricians” cant give any advice because yous dont actually know what to do in my situation.
I know in my profession if someone asked me for help id be glad to give some advice, but suppose when you dont know the answer its hard to give advice
Please go look up the meaning of a forum

 

[Afoster615]

That statement is not towards the last 2 comments.

 

[telectrix]

but suppose when you dont know the answer its hard to give advice

without knowing all the factors involved, nobody can give a definitive answer. if i ring my GP and tell him i've got a pain in my arse, how will he know how to advise whether to put the kids in care , get a divorce, stop advising DIYers, or take tramadol?