Electric connections to outbuildings

[Deleted member 73437]

Hello,
I would begrateful for some advice.
I have recently moved into a property which has two detached outbuildings, one used as a garage and the other as a workshop, no heavy machinery just the run of the mill drills and saw.

The outbuildings are connected to the house in this manner;
From main ConsumerUnit, 80A / 30mA RCD via a 32A MCB to the Garage Consumer Unit,63A / 30mA RCDvia a 32A MCB to the Workshop Consumer Unit, 40A / 30mA RCD. The circuit is earthed via an earth rod ouside the house.

What I would like to know is does this meet the existing requirements or is it an overkill?

I am not after technical details as I intend to contact a local electrician. What I will be grateful for is some information, if this set up does not meet standards, so that I can have an idea for when I get the quotes.

Kindregards

 

[GLENNSPARK]

cant see an issue here...

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depends on the CSA of the supply cable....you may be able to up the MCB top end....

 

[GLENNSPARK]

just a thought....is the supply cable here an SWA?...if so then go for an 100mA s type RCD top end with your finals given fault protection by 30mA RCDs (which you already have there)...so as to avoid the discrimination issues with RCDs of the same type in series

 

[Richard Burns]

Yes you seem to have three 30mA RCDs in series which is pointless, but it is possible that each RCD is not in series depending on how each CU is wired.
You also have two 32A MCBs in series which provide no discrimination.
The discrimination issues would be technically a breach of the regulations if there is danger from the power outage of the entire run because of a fault at the end of the run, but this would likely not be the case in a domestic situation.
Other than that then as Glennspark says above.

 

[Deleted member 73437]

I am very grateful for your responses.

The cable from the house to the garage and the workshop is 10mm twin and earth which is housed in a very tough plastic conduit and runs above ground fixed to the walls.

Glennspark do you mean change the 80A RCDin the house consumer unit to a 100A?

Also, will it help to have an earth rod fitted to each of the consumer units?

Once again,many thanks

 

[telectrix]

Glennspark do you mean change the 80A RCDin the house consumer unit to a 100A?

no , he means the 32A MCB. feeding the 10mm. this can be uprated to a 40A, what is the present earthing system?

 

[Deleted member 73437]

Glennspark do you mean change the 80A RCDin the house consumer unit to a 100A?

no , he means the 32A MCB. feeding the 10mm. this can be uprated to a 40A, what is the present earthing system?

The earth is through an earth rod just outside the house

 

[telectrix]

then adding extra rods might be advantageous. what's the Ze

edit: sorry, just re-read yor OP. get your local spark to work everything out for you.

 

[Deleted member 73437]

then adding extra rods might be advantageous. what's the Ze

edit: sorry, just re-read yor OP. get your local spark to work everything out for you.

Manythanks, I do intend to get a local electrician to carry out an inspection ofthe whole system, in fact I have been phoning around this morning. I just wouldlike some ideas before I am baffled with science and fobbed off with a totalrewire or something.

From thereplies, I assume overall the system is fine bar from needing some tweaking toimprove the overall safety.

 

[telectrix]

if the installation is post 1980, then it should be fine. as you say, maybe a bit of updating required. be aware though, that many installations will not comply fully with current regs. that does not mean that they have to be updated. it's new work that has to be installed to latest regs.. earthing and bonding arrangements need to be inspected and if not adequate, will need upgrading.

 

[Deleted member 73437]

if the installation is post 1980, then it should be fine. as you say, maybe a bit of updating required. be aware though, that many installations will not comply fully with current regs. that does not mean that they have to be updated. it's new work that has to be installed to latest regs.. earthing and bonding arrangements need to be inspected and if not adequate, will need upgrading.

Yes the installation is post 1980, it was done as part of house extension. Thanks for clarifying the current situation. Already, one electrician I spoken to over the phone has suggested that the system does not seem to meet the new regs and therefore any works would be classed as ¨new works¨therefore the whole system might need to be changed. This is what I am trying to avoid, hence my seeking advice.
The first electrician who responds in the same vein as you kind folk will get the job. Many thanks again.

 

[telectrix]

i'm sure there are a few forum members in your area. look on the electricians in your area forum, or post a thread inj the general forum, titled " electrician wanted, ipswich"

edit: you're a bit outside my catchement area .LOL.

 

[Engineer54]

Take a few photo's of your 3 X consumer units, preferably with the covers removed so that we can see what you actually have. We can then recommend the best way to go ahead with as to, what to ask the electrician to quote against...

I would however recommend, that you do install an earth rod (2 X 5/8'' coupled together for depth) at each of the 2 outbuildings as a matter of course. Connecting these 2 additional rods with the house's main rod will not only serve the two outbuildings, but also lower the overall Ra value, which serves the main house installation too!!

 

[GLENNSPARK]

Take a few photo's of your 3 X consumer units, preferably with the covers removed so that we can see what you actually have. We can then recommend the best way to go ahead with as to, what to ask the electrician to quote against...

I would however recommend, that you do install an earth rod (2 X 5/8'' coupled together for depth) at each of the 2 outbuildings as a matter of course. Connecting these 2 additional rods with the house's main rod will not only serve the two outbuildings, but also lower the overall Ra value, which serves the main house installation too!!

yeah....caus you just know it`l be a 3/8" stalk....doin nowt....lol...

 

[telectrix]

if you can manage to get a rod through the foul drains, the Ra should become good every time the bog gets flushed. :ciappa: