New insall in workshop and CU change in house advice

[PHS]

Morning everyone,

I am looking for some advice and knowledge to help jog my memory as it’s been a few months since I finished my course and due to health reasons, I had to give up my job on site as a mate and start working for myself after 4 months off work.

This will be the first job I have had that lets me join a competent bodies scheme as they require a “big” job to come down and assess.

Basically, a fella has had a workshop built in the garden and wants it powered up and the old consumer unit in the house is extremely outdated and will be replaced too.

If you could please look over what I intend to do and pin point any mistakes or alterations that I may have over looked I would be most grateful.
The old CU in the house is fitted with B30 and B5 breakers from http://www.gepowercontrols.com



I would be looking at replacing this with a 11 Way Metal Consumer Unit-100 Amp Switch with a 63 Amp 30mA RCD 2 Pole-Wylex, Two 6 Amp Wylex MCB's, Three 32 Amp Wylex MCB's and a non protected 40 Amp Wylex MCB for run out to workshop.

30m run of 6mm SWA out to workshop and a 5 Way Metal Consumer Unit - 100 Amp Switch with a 40 Amp 30mA RCD 2 Pole - Wylex, One 6 Amp Wylex MCB running Two 2ft 18w Non Corrosive Weatherproof Fluorescent Light Fittings and Two 20 Amp Wylex MCB's on the Two radial circuits.

I would greatly appreciate any feedback on this set up as, although i have been a mate for 4 years and done the course, i'm still wet behind the ears after having so much time off work and not being around the industry for a few months now.
Many thanks in advance

 

[DPG]

Not a good idea putting all 5 MCBs on the one RCD. Daz

 

[Guitarist]

Current earthing arrangement?

 

[PHS]

Not a good idea putting all 5 MCBs on the one RCD. Daz

no worries, i can put in two and split the load
cheers

 

[PHS]

Current earthing arrangement?

its a TN-S system
cheers

 

[Engineer54]

You'll need what they call, a ''High Integrity'' CU where at least one of the MCB's will be unprotected by either of the RCD's. Either that or an all RCBO CU, where the supply out to the workshop will be protected by an MCB.


I take it you will be using an appropriately sized SWA buried cable for this new workshop supply??

 

[telectrix]

BG 13 way hi-integrity CU was £60 from screwfix. not metal box though. why you want metal box?

 

[Octopus]

I'd go down the RCBO route - how old is the property/wiring?

 

[PHS]

BG 13 way hi-integrity CU was £60 from screwfix. not metal box though. why you want metal box?

was only going with metal for ease of termination of the swa gland ?

 

[PHS]

I take it you will be using an appropriately sized SWA buried cable for this new workshop supply??

the cable will be run along the wall of the house, across the top of a fixed gate and along the wall of the garage to the new workshop, all clipped and out of the way of any traffic.

 

[Guitarist]

was only going with metal for ease of termination of the swa gland ?

You can do that easily into a decent plastic CU (as long as you know what you are doing).

 

[Engineer54]

was only going with metal for ease of termination of the swa gland ?

You can use a metal adaptable box to terminate the SWA cable, mounted directly under the new CU, and take the SWA cable tails through into the plastic CU...

 

[PHS]

10 Way Hi Integrity Dual RCD + 100A Main Switch Consumer Unit

would i be better going for something like this then for the house CU?
with a 40 amp rcbo for run out to workshop?

 

[Octopus]

10 Way Hi Integrity Dual RCD + 100A Main Switch Consumer Unit

would i be better going for something like this then for the house CU?
with a 40 amp rcbo for run out to workshop?

yes. whats the bonding like?

 

[PHS]

yes. whats the bonding like?

to the best of my knowledge, its ok

 

[telectrix]

just need to verify the connections to the gas and water then.

 

[PHS]

i suppose i have to go get myself a Torque Setting VDE Screwdriver as well now too, seeing as its my test piece?
there was a lot of talk about them in the centre and i know there is mixed reviews as to the need for them

 

[telectrix]

waste of space.

 

[Guitarist]

waste of space.

Well, I thought that. Now that I have one though, I find that I use it all the time and actually like it. Go figure....

 

[Engineer54]

10 Way Hi Integrity Dual RCD + 100A Main Switch Consumer Unit

would i be better going for something like this then for the house CU?
with a 40 amp rcbo for run out to workshop?

The reason you are going for a High Integrity CU, is that you have an unprotected way (MCB) at the house CU. Otherwise you're not going to have any discrimination between the RCD device in the workshop CU and the RCD in the house CU!!! The SWA sub-main does not require RCD protection.....