Garage CU

[WOH64Dek]

I would like some advice please.
Ive been asked to change a garage cu which has rewireable fuses. The garage has a 3 core 6mm swa cable coming from the cu in the house and is connected to 16a mcb. The cable has a gland fitting at cu in the house but has not got gland fitting at cu in the garage, would it be ok to fit this.

http://www.screwfix.com/prods/33248...nits/MK-Sentry-4-Way-RCD-Garage-Consumer-Unit

 

[Steve]

It'd be ok, yeah, but not perfect. 6mm² will be a pain to gland into that enclosure.

Far better to fit something like this:

http://www.tlc-direct.co.uk/Products/WYNH506.html

A proper 5 way board (not that TWO way toy you linked to). A couple of RCBOs and you're sorted.

The two way "garage" boards are fine, but have limitations.

And why a 16A MCB at the house? is the feed RCD protected?

And what do you mean "you have been asked"?

 

[WOH64Dek]

Thanks for the reply
To be honest i didnt check if feed is rcd protected or not.
I recently did part p & 17th edition, so i could do my own electrical work ie extra sockets, lights. I didnt have any intentions of doing cu changes. A neighbour asked would i have a look at the cu in his garage. If i was to do it, i wanted to know what was the best way to go about it.

 

[JohnnyG]

If you've recently passed the C&G 2382 & a form of DISQ you should know that if you are to do this work it's notifiable to the LABC.
If you're not a member of a competent persons scheme and as (no offence) you don't seem confident in doing it, it may be worth your while employing a registered competent person to do it for you whilst you help them and gain some valuable experience

 

[ban-all-sheds]

I recently did part p & 17th edition

Part P is not a qualification or exam.

so i could do my own electrical work ie extra sockets, lights.

You're not a member of a Competent Person scheme - whatever qualifications you have make absolutely no difference to your need to notify work. Full marks for formalising your learning, but I can't see how it lets you do your own electrical work.

Have you bought a set of testers?

I didnt have any intentions of doing cu changes.

What if you needed to change yours?

 

[Electrifying]

To be honest i didnt check if feed is rcd protected or not.
.

Doesn't have to be, so don't worry about it

If it's SWA from the house CU to the garage then it's mechanically protected - no need to RCD the distribution cable.

 

[WOH64Dek]

"Part P is not a qualification or exam".

I didn't say it was and my question wasn't about Part P.

"You're not a member of a Competent Person scheme - whatever qualifications you have make absolutely no difference to your need to notify work. Full marks for formalising your learning, but I can't see how it lets you do your own electrical work."

I am fully aware that I still need to notify my work. You have to do work and have is assessed before you can become a member of a Competent Persons Scheme which is what I intend to do.

"Have you bought a set of testers?"

Not yet. I only said I had been asked by my neighbour to do some work not that I was jumping in and doing it. I wouldn't undertake any work on my neighbours property or my own, until I had the right equipment.

"I didnt have any intentions of doing cu changes.
What if you needed to change yours?"

Obviously I would seek advice from someone with more experience than me.

I fully agree with JohnnyG in that I need to gain some valuable experience.

 

[Steve]

To be honest i didnt check if feed is rcd protected or not.
.

Doesn't have to be, so don't worry about it

If it's SWA from the house CU to the garage then it's mechanically protected - no need to RCD the distribution cable.

No, it doesnt have to be, but he should check anyway! If there is an RCD then he needn't fit any at the shed. Is there is an RCD then he must fit one at the shed.

I suppose you go around tacking things onto cables without finding out where the cable comes from? No. So why advise anyone else to?

 

[Electrifying]

To be honest i didnt check if feed is rcd protected or not.
.

Doesn't have to be, so don't worry about it

If it's SWA from the house CU to the garage then it's mechanically protected - no need to RCD the distribution cable.

No, it doesnt have to be, but he should check anyway! If there is an RCD then he needn't fit any at the shed. Is there is an RCD then he must fit one at the shed.

I suppose you go around tacking things onto cables without finding out where the cable comes from? No. So why advise anyone else to?

Is that not the most ridiculous comment ever!

He has already told you that the cable is connected to a 16A MCB at the house CU (which you questioned??) - so he must have looked and therefore knows where it's coming from.

If it's coming off the RCD side of the board, then fine, he doesn't need an RCD in the shed - but this isn't what you were implying, is it.

Your question implied that the feed had to be RCD protected and that he was wrong not to have checked

And why a 16A MCB at the house? is the feed RCD protected?

Too many people are all to ready to jump down peoples throats on this forum

 

[ban-all-sheds]

"Part P is not a qualification or exam".

I didn't say it was

I recently did part p & 17th edition

and my question wasn't about Part P.

You wouldn't have been the first person to think that electrical qualifications meant he could DIY without notification.

I am fully aware that I still need to notify my work. You have to do work and have is assessed before you can become a member of a Competent Persons Scheme which is what I intend to do.

so i could do my own electrical work ie extra sockets, lights. I didnt have any intentions of doing cu changes.

Well I hope you can see why I wrote what I did.
That, particularly the highlighted part, really didn't read as if you were planning to register with a Competent Person scheme, and therefore work as an electrician, because an electrician wouldn't do particularly well if he didn't plan to change CUs, and I would seriously doubt the commitment, competence and confidence of anyone claiming to be an electrician but not wanting to change CUs.

 

[Steve]

I suppose you go around tacking things onto cables without finding out where the cable comes from? No. So why advise anyone else to?

Is that not the most ridiculous comment ever!

Not really, considering your ridiculous implication that it matters not what is supplying this cable.

To be honest i didnt check if feed is rcd protected or not..

Doesn't have to be, so don't worry about it

He has already told you that the cable is connected to a 16A MCB at the house CU (which you questioned??) - so he must have looked and therefore knows where it's coming from.

Show me where I questioned the supply overcurrent device. The issue here is not about the overcurrent protection, its about the RCD earth fault protection. I did query the use of a 16A MCB supplying 6mm² cable, but wouldn't you? Doesn't it seem odd that someone would spend extra on 6mm² cable and protect it with a 16A device? And the garage CU's usually have a 16A MCB for the sockets. There's be no discrimination, therefore its a bad design.

If it's coming off the RCD side of the board, then fine, he doesn't need an RCD in the shed - but this isn't what you were implying, is it.

Your question implied that the feed had to be RCD protected and that he was wrong not to have checked

is the feed RCD protected?

What exactly did I imply here? Nothing. I asked a question.

Too many people are all to ready to jump down peoples throats on this forum

Too many people are all too ready to give bad advice.

You have to remember many people come here with a little knowledge and think they know it all. You have to cover all bases. This is why we ask a lot of questions. I implied nothing in what I said. I simply asked questions. It is often by reading these questions that people are scared off doing a job, as they realise they dont know as much as they previously thought. By making broad sweeping statements like "it doesnt have to be" and "dont worry about it", you could be letting the guy make a bad mistake.

Calm down calm down.

 

[Electrifying]

I would like some advice please.

So, instead of all the criticism and argument and questions, someone could have simply replied, (in one post instead of ten) :-


Hi WOH64DEK,

Swap the 16A MCB for a 32A MCB.

If the circuit is on the RCD side of the house CU, then no need for RCD protection at the garage - buy a CU with an ordinary main switch.

If it's not RCD protected at the house, then you'll need RCD protection in the garage (like the CU in your link) - the distribution cable doesn't need RCD protection if it's SWA all the way.

Don't forget, full set of tests, EIC issued and it's notifiable work

If you don't feel competent or you don't want to pay to notify, get a sparky in, mate.

Good luck.
.
.
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See, not difficult, is it

 

[RF Lighting]

You're doing it again!

What makes you think that you can just swap the 16A CB for a 32A CB, no questions asked?

 

[Steve]

So, instead of all the criticism and argument and questions, someone could have simply replied, (in one post instead of ten) :-

I wasnt arguing with the OP. Ban seems to have started another Part P debate with him though.

Hi WOH64DEK,

Swap the 16A MCB for a 32A MCB.

You cant say this. There may be insulation and distance factors at work here.

If the circuit is on the RCD side of the house CU, then no need for RCD protection at the garage - buy a CU with an ordinary main switch.

If it's not RCD protected at the house, then you'll need RCD protection in the garage (like the CU in your link) - the distribution cable doesn't need RCD protection if it's SWA all the way.

All well and good. But its worth also pointing out that RCD protection at the house for a garage is not desireable, as to reset you have to go back to the house, and it'd knock off half the house too. Local, sockets-only protection is preferred. Lights in the garage dont usually need RCDing, and thats even less desireable as if its dark and the RCD trips, you're left with a spinning power tool in your hand . . .

Don't forget, full set of tests, EIC issued and it's notifiable work

If you don't feel competent or you don't want to pay to notify, get a sparky in, mate.

Good luck.
.
.
.
See, not difficult, is it

Granted, but can you see why we'd rather ask the questions and try to get them to think for themselves a little bit? We like to have all the facts before we go charging in with a blanket answer. Theres a saying we use, "cant see it, cant quote it". I guess another is "cant see it, cant design it".

 

[Electrifying]

You're doing it again!

What makes you think that you can just swap the 16A CB for a 32A CB, no questions asked?

6mm Armoured cable - Ref method D (direct in ground or in ducting in ground, in and around buildings) - three or four core cable - current carrying capacity 38 Amps

Unless you think he's doing something worse with it