Adding a 2 way unit to a garage

[Mfctitch]

Evening everyone

I have been asked to price to add some more sockets and lights to a garage plus a few out side sockets.
now the garage already had a supply from the house via SWA cabling which just feeds a socket and the lights via a fused switched spur.
now the consumer unit in the house is an old "Ashley & Rock" with Supasafe MCB's. with blue writing if that helps the whole lot is protected with one main RCD.

Now for my question.
I know that I can fit just a 2 way unit but I was thinking that with more sockets and some of them outside it would be better to fit an RCD in the garage.
but I need this to trip before the house RCD trips so any suggestions would be great.

Thanks for all suggestions

 

[GLENNSPARK]

I will try and get back to the house before the weekend and take some photos of the problem.
Plus I will also check the earthing arrangements
as see if the SWA goes into the consumer unit.

eh?...
come on fella....first thing you do is this when survaying a proposed new install...
jesus....

 

[eganelectrical]

Top end as I the house?

Hey mfctich I advised about time delayed in the house and was ripped to shreds then one of the ones who ripped in changed his tone and said what I originally said!! Are you with me on that one?

 

[Engineer54]

Top end as I the house?

Hey mfctich I advised about time delayed in the house and was ripped to shreds then one of the ones who ripped in changed his tone and said what I originally said!! Are you with me on that one?

NO!! You were suggesting an overall S type to protect both the house and the garage!! That's not a helpful solution!!

 

[iconnect]

Depending on earthing system I would split tails put in sub board sub main swa on mc. Garage consumer with rcbos. If not give them opitions of how it can be done and the effect it will have on the house. Again difficult to say anymore without earthing arrangement and bit more info. When I do a quote I also take pics of the head, consumer unit/fusebox, and any other parts that are relevent. I only take them on my iphone but its easy to forget or not write down things like what breakers and how circuits are connected etc

 

[eganelectrical]

time delay

But wouldn't a time delay in the garage cause the house to trip first??

 

[Deleted member 9648]

1. As long as the system is not TT there is no requirement to RCD the SWA so find a way to get the SWA off the main house RCD and install a 30ma RCD at the garage end,this could be via a henley block at the intake or altering the configuration of the existing CU-not rocket science.
2.You cant put an S type in the house without ensuring final circuits in the house remain 30ma RCD protected assuming they require it,again the only way would be to alter the configuration of the CU....or convert to main switch and fit RCBO's-not rocket science.
3.If there is one 30ma RCD at the house end covering all then adding a few sockets etc isnt changing things a great deal....if the client doesnt want additional work/expense to alter the system to provide discrimination then leave it as it is and fit a standard main switch cu in the garage-not rocket science.

- - - Updated - - -

But wouldn't a time delay in the garage cause the house to trip first??

Yes indeed....the rule of discrimination is that the slowest operating device should be at the supply end

 

[partypest]

I'm surprised at this thread for a couple of reasons. My first surprise is that it took so long for someone to suggest that the submain needs to be separated from the main RCD but the biggest surprise was the amount of vitriol in some of the members replies. I thought this was a help forum? If this chap's scratching his head and looking for ideas (and we've all been there), he probably thought he was coming to the right place to ask.

 

[Deleted member 9648]

I'm surprised at this thread for a couple of reasons. My first surprise is that it took so long for someone to suggest that the submain needs to be separated from the main RCD but the biggest surprise was the amount of vitriol in some of the members replies. I thought this was a help forum? If this chap's scratching his head and looking for ideas (and we've all been there), he probably thought he was coming to the right place to ask.

Have a look at posts #2 and #3......this is the sort of thing which results in threads degenerating into vitriol. These people are charging clients for their expertise.

 

[shanky887614]

surely it would be easier and much less hastle to put the garage before the rcd and put it on an rcbo

that way it wont trip the house.

 

[Mfctitch]

Morning Everyone
And thank you again for all comments.
I take on board all criticism about coming to the forum with not enough info.
I am trying to get back to the property sooner rather than later and will report back with all relevant info.
I do have to say and this is my inexperience showing that I did not realise how hard it would be and I can see why some people would just take the easy option.
if in the mean time please keep all suggestions coming.

 

[Mfctitch]

Have a look at posts #2 and #3......this is the sort of thing which results in threads degenerating into vitriol. These people are charging clients for their expertise.

Thanks for that but as is quite evident my expertise is not that great but my willingness to do a good job rather than just a job is greater.
and this I hope is reflected in the time I and all the other members have spent on this question.

 

[partypest]

If you think he should know better, which is true enough, and you don't want to help him, don't help him. I think it's more likely that the old CU has been installed in such a way that pulling the SWA, or whatever the submain is, out and doing a Henley block etc, is going to make a whole mess of someone's house. Maybe he was hoping that someone out there has dealt with similar and found a solution. Maybe he's not that good at communicating on forums. Maybe he is a Electrical Trainee starting out or a DiY'r, I don't know and he's not saying. All I'm saying is, this is a help forum and we can choose to help or not. As somebody once said, if you can't say nothin' nice, don't say nothin'.

 

[Deleted member 9648]

Thanks for that but as is quite evident my expertise is not that great but my willingness to do a good job rather than just a job is greater.
and this I hope is reflected in the time I and all the other members have spent on this question.

My post was aimed at some of the answers you have recieved...(posts 2-3 for a start)....not you.

 

[Mfctitch]

Thank you party pest for that.
to answer some of your points yes by the looks of it 'm not doing a very good job of communicating on here but I think that we getting there.
And this will get EVERYONE going
yes I am as people like to put it a Electrical Trainee, who has "passed" with NICEIC. I don't class myself as an electrician just as an installer who with the help of people such as yourself will hopefully try and install in a safe manor.
I have been in self employed for some 20 years now so I must be doing something right.
The reason for joining one of these schemes is that when I go to fit a bathroom or a kitchen I do not have to wait for an electrician to turn up for the purpose of installing a socket or two. When he is up to his eyes doing commercial work and there fore holding me up.
And on a brighter note I know that many of you time served electricians do not think much of us, but having to stick your name on a bit of paper does make you think twice when doing a job.

 

[Octopus]

The only thing I'll add after post 59 is that if your expertise is kitchens and bathrooms why are you messing with a garage supply?

Being a Electrical Trainee is irrelevent imho, but if you are only doing the "odd" electrical job then to get up to speed with the plethora of different installations, and styles and types of installs could take you decades.