options for workshop supply

[A032701]

just wondering what people would think would be the best way of doing this.

i have got to provide a supply up to a workshop in a garden (about 80 mtrs from the house). it will run underground all the way and then in the subfloor of the house that is currently being worked on all the way to the db.

 

[Squid]

What will the cable be supplying in the workshop, a single light and a double socket or a lathe and other heavy duty equipment?

 

[A032701]

The consumer is a fan of landrovers and that will be his garage for it. so there will be possibility of welders, grinders, lathes etc
i was thinking of putting the supply on 40amp mcb

 

[Dustydazzler]

80 metres is a substantial distance , will require a proper calculation imo

You could be looking at a 40a c curve mcb to prevent tripping

 

[Yozza19]

Still approx 25mm cable

 

[Charlie_]

Tns?
I would ask for a duct to be laid from the house to the garage with a rope inside.
Pull through a 3 core 16mm swa and also a cat6 cable..

 

[A032701]

thanks everyone-
the current supply is tns
i was thinking of laying a duct then pulling through some double insulated 16mm through and a 10mm through for earth.

 

[ruston]

Due to the location heating may be a fair consideration of the loading , but I can just see a nice pot bellied stove.

 

[Charlie_]

Definitely go for swa. Make sure you get his full load requirements though, 25mm may be required

 

[A032701]

ok. will ask him in more detail as to what he will be using.

 

[Charlie_]

Is the 80m from house to garage or from cu to garage?

 

[A032701]

cu to garage.

 

[The Ghost]

I get 10.08 vd on 16mm² and 6.3 vd on 25mm they can carry 78A and 99A respectively assuming 0.7 m. depth and so on. Personally SWA for me.

 

[ruston]

I would use SWA too.

 

[Toneyz]

It seems like he is going to be using this garage on a semi-professional bases/serious hobby/past time. Full due consideration needed especially if he has other enthusiast mates helping also using equipment plus the possibility of some heating/water heater. How big is this workshop?

 

[Strima]

I'd also be leaning to a fuse at the supply end. Any other services in this workshop such as water, gas etc?

 

[Deleted member 105166]

It may be worth the customer enquiring of the DNO the cost of providing a separate supply to the garage. Depending on routing on their side, this may be relatively inexpensive and would give greater scope.

 

[A032701]

thanks everyone.
the garage/shed will be around 9mtrs x 10 mtrs.
their will most likely be water but no gas.
i will look into the possibility of getting a separate supply in

 

[TJ Anderson]

As you haven't provided a design current it is easier to use In. This also means you are covered for volt drop right up to the point of overload of the distribution circuit. 32A you could go 10mm, if you go 16mm, you can do 50A. Using In instead of Ib and youve got a VD just under 5% for both.

Check Ze. You have TNS so could be up to 0.8 ohms already....

C40 60890 max Zs is 0.54

R1+R2 for the 10mm is 0.35

R1+R2 for the 16mm is 0.23