Wiring for detached Garage

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Hi all,
Hope everyone is well in this now crazy world.
I'm looking to buy a house which has a detached double garage currently I believe the electrics are spured off the house ring from the lounge which is around 4 foot away using SWA running under the pathway.
If I bought it I would be looking to run a compressor as well as other wood working machinery (table saw). Obviously they wouldn't all be run at the same time, but also don't want to overload circuits.
My preference would be to have the garage on it's own circuit from the CU but the CU is at the other end of the house about 15 meters away in the kitchen which is only 3 years old.

I done 16th edition regs a number of years ago, but not in that type of job anymore. Obviously I would get all the work done by a suitable electrician, but would like to understand my best route to be safe and also get the power that I need but not cost a fortune.

Any ideas appreciated.
Cheers
Adam

 

[AndyPRK]

I’d be tempted to leave it.

Usually frounded upon, but you could put a mini cu in the garage.

6A lights
20A for sockets.

The 20a would trip long before any 13A fuse and would tell you that you were close to the limit

 

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I’d be tempted to leave it.

Usually frounded upon, but you could put a mini cu in the garage.

6A lights
20A for sockets.

The 20a would trip long before any 13A fuse and would tell you that you were close to the limit

Thanks, i did think about leaving it. I would just be worried that if I was running the lights, and a 2.5hp compressor and say maybe another small power tool such as an angle grinder that I would overload the circuit. I would also like to add another 1 or 2 double sockets in there too.

 

[AndyPRK]

I don’t think you will overload it.

 

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Thanks Andy. Think maybe I am over thinking things. When I get in there I will get someone to test the wiring anyway and take it from there. I guess worst case I would have to run a separate cable from the CU to the garage if it is an issue, just would be a bit of a nightmare / upheaval.

 

[jonwmm]

I'm no electrician but have the same set up (new build with detached garage) and the site sparky wired a few additional sockets in my garage which are all fed of the downstairs socket ring.

One of them is for my plug in car charger and he said it will be fine, had no trouble yet and often use the sockets whilst the car is on charge, I'm not sure on amps but pulls about 3.5kw

 

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I'm no electrician but have the same set up (new build with detached garage) and the site sparky wired a few additional sockets in my garage which are all fed of the downstairs socket ring.

One of them is for my plug in car charger and he said it will be fine, had no trouble yet and often use the sockets whilst the car is on charge, I'm not sure on amps but pulls about 3.5kw

Thanks for the info. I presume it's a electric car for that type of power? Although that equates to about 14 amps. Good to know though that I will probably be ok.

 

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Thought I would update this thread. I've now moved in and looked at it in more detail.
The SWA coming in ti the garage is 4mm. The House CU has a 20A MCB and is also protected by a RCD. The Garage CU has a 20A MCB for a radial circuit of 2 double sockets and a 6A MCB for lighting. Is it possible to have a RCD in the garage too? Does this setup sound ok so far or should i get it upgraded? Many thanks.

 

[winston1]

Having two 20A MCBs in line is stupid. With a fault either one or both will trip. Likewise a second RCD in the garage is pointless for the same reason.

 

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Having two 20A MCBs in line is stupid. With a fault either one or both will trip. Likewise a second RCD in the garage is pointless for the same reason.

This is what i thought also. So what MCB should there be in the 4mm swa? From what I remember from doing 16th regs a long time ago I think it's 32A.

 

[Taylortwocities]

If it really is 4mm SWA then it could be protected by a 32amp MCB.

 

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If it really is 4mm SWA then it could be protected by a 32amp MCB.

It says 4mm on the cable, but not checked the terminations.