Running new cable to supply garage from sub-board

[Billsays]

Fair enough your still learning your trade, and well done for asking when your not 100% sure. A good trait........
When you boil it down you have a 40A MCB supplying 2 x ring mains, a 32A hot tub, a 16A radial (which you haven't given any details of) and 2 lighting circuits. You must see that this is likely to overload the 40?
As much as a pain as it is, you need to tell your customer that they need to replace the supply to the garage.
Its not easy when you are just starting to tell the client "bad news" and other chancers may come along and do just what you said. However if you intend to be a decent Electrician you must get used to the idea that the customer is not always right.

 

[buzzlightyear]

Fair enough your still learning your trade, and well done for asking when your not 100% sure. A good trait........
When you boil it down you have a 40A MCB supplying 2 x ring mains, a 32A hot tub, a 16A radial (which you haven't given any details of) and 2 lighting circuits. You must see that this is likely to overload the 40?
As much as a pain as it is, you need to tell your customer that they need to replace the supply to the garage.
Its not easy when you are just starting to tell the client "bad news" and other chancers may come along and do just what you said. However if you intend to be a decent Electrician you must get used to the idea that the customer is not always right.

wow, how did you come to that, read post 6!

 

[kmulcahy1994]

Thanks for the reply. And i an see exactly where your coming from. I havent looked into this in detail so i dont even know what size cable they have used to supply the submain. So if its the max cable size for that 40A MCB then i will not supply the garage and will have to find another route. The old garage supply runs under the house which has a 450mm deep void, fingers crossed I can fish the new supply that way!

 

[Billsays]

wow, how did you come to that, read post 6!

Lol.......your right.....MODS close the thread, Buzzer has solved it!
(I took post 16 to mean your succinct reply was not quiet clear enough!)

 

[GlenTavener]

You can run your new supply to the garage from wherever it takes your fancy
Before you decide from what location, you need to assess the existing cable size,the protection it affords, the present load and whether it has the capacity to cope with the calculated additional load and the earthing requirements and protection of that load

These questions are often encountered by electricians who have trained to obtain the skill to adequately answer so that the installation is safe for the user

There are people who just add cables to connections points and get things working, safety is not considered and/or mostly understood,but there are people who seek help or advise from those with the training to assess these installations
Shoving loads on systems willy nilli is not recommended

Spot on, almost anyone can make it "work" but make no attempt, or incapable of dealing with possible faults that may lie ahead, "risk assessment" does not come into it. I have, like many on here, seen incredible botch ups. In the long run its just as easy to do it the right way, yes and spend a bit extra, to ensure everyone's safe operation of the things you install. I had an admiral very proud of his work in his own home, yes all the sockets worked, wired in 1mm t/e connected to existing ring circuit, yeah it worked. Supply to his stables, oh boy, again 1mm t/e spade slot across the lawn then up the drain pipe and under the eves to a consumers unit, yeah it worked! I know and trained people on here know how to assess these situations and know what has to be done for a proper installation. I so dislike DIY know it alls.