new supply to granny flat

[dean mac]

hi guys my mate wants to run in an armoured cable for a granny flat hes building its going to be all electric, shower cooker plus storage heaters,ive said 25mm should be ok its a 15 metre run what do u guys think,also i would think a new supply should be put in as he was planning on splitting the tails back in the house

 

[Evans Electric]

25mm would be well in, Dean, but do you think Granny will be pulling 100amps, I don't TBH.

I've done similar jobs with a 10mm , I think you'd be safe with 16mm tops.

Afterthought, how do you propose to do the off-peak heating, seperate sub-main or what ?

Deke

 

[dean mac]

im not sure yet if there coming off the house supply which i would think would be to much,so if a new supply is going in i would of thought because everything is going to be electric and no gas

 

[Evans Electric]

Bit OTT to have a new supply, when you say Granny flat I think of a small lounge,a small bedroom, kitchenette and shower/toilet. Should all run from the existing mains, you'd think.

 

[betty swollocks]

i would have thought 10mm swa would be more than enough,

clipped direct will allow 72A and considering most 3 bed semi's i work on have a 60A main fuse, you would be more than covered,

a new supply would be complete overkill unless your mate is a tight wad who doesnt want to pay for the power granny will use.

i think a 50A mcb from exisiting consumer unit will more than suffice, depending obviously on the current supply fuse and original house requirements.

 

[The Godfather]

and considering most 3 bed semi's i work on have a 60A main fuse, you would be more than covered,

Depending on age and area, Betty.

100A could also be considered to be the norm.

regards

The Boys

 

[green-hornet]

Me personally would ask for a new supply.

The reason being future use and saleability.

If the granny flat becomes surplus to requirements, with an independant supply it could be rented out or sold.

If this is not going to happen then a 10mm swa would for the eventual loading be ample given the cable length.

 

[dean mac]

its going to have storage hheaters as i mentioned so wouldnt he need a new supply

 

[Apache]

its going to have storage hheaters as i mentioned so wouldnt he need a new supply

is main house on economy 7?

 

[dean mac]

25mm would be well in, Dean, but do you think Granny will be pulling 100amps, I don't TBH.I've done similar jobs with a 10mm , I think you'd be safe with 16mm tops.

Afterthought, how do you propose to do the off-peak heating, seperate sub-main or what ?

Deke

sorry deke didnt see the end of ur post,what do u thinks best,i favent got the job he just asked me about the supply

 

[dean mac]

is main house on economy 7?

not sure apache havent been there will look tomoz

 

[Apache]

not sure apache havent been there will look tomoz

cos if it is then assuming we have spare capacity should be ok? If loading is going to be an issue why not put the storage heaters on a timer so the ones in the granny flat charge from 4am and the house ones from midnight?

 

[Evans Electric]

You need to check the load of the existing off-peak, see if you can add ,say 5kw to it .

Assuming, as Patch says, that there is existing Econ 7 to add to.

deke

 

[dean mac]

cheers lads