armoured cable

[iamagirlremember]

Hi,

My partner has just brought some land and eventually wants to build a property on there (6 bed house-hopefully ) plus farm bulidings, possible chicken/goat shed.

He needs 200m initially.

Would 16mm 3 core be sufficient. I havent a clue and nor does he really.

Best to be more me thinks!!

Does this sound ok???

Many thanks

 

[SgtTrojan]

To supply what? The goat's Sky TV box or what?

Question 1 is:
What is the maximum demand? i.e. How much power will you be demanding from the supply authority?

And 200 metres of supply cable. I hope your partner figured in a couple of grand for the cable installation alone :O

 

[peterduckett]

Well looking at the TLC voltage drop it may be able to take 2.7 kw over that distance

I hope you don't want to boil a kettle!!

 

[iamagirlremember]

I have had quotes of up to 1300 for the cable. But he can dig trench and fix, (he may become hairless at this point!!!)

I dont know how much the demand will be, havent a clue

But will 16mm 3 core cover every eventuality??

 

[iamagirlremember]

Please explain further peter, i am a girl remember!!!

 

[SgtTrojan]

Not for 200m no chance. The old meter tails used to supply 16mm squared but that was only for a couple of meters in length for 63A. We now get 25mm squared to cover the standard 100A but again for only a couple of metres of cable.

For 200m a calculation will need to be made. If you add a 16mm and you have will have just installed yourself some heating in your field to keep your goats tootsies warm!

Refer to question 1.

 

[iamagirlremember]

Ok so I need to use my swede!

But i dont know what items consume what, is their a website etc that can give me what supply they need, I am calculating in voltage or amps, i am a donut sorry

 

[peterduckett]

The supply voltage drops for every meter of cable you have.

So the supply end may be 240v the other end maybe 200v to over come this you normally install a thicker cable.

I believe the tolerance of this is 3% for lighting circuits and 5% non lighting circuits.

With that in mind the maximum is 2.7kw or 4.5kw respectably nost house with a 60amp fuse can draw around 13.8kw

so no it wont be suitable

 

[peterduckett]

Ok so I need to use my swede!

But i dont know what items consume what, is their a website etc that can give me what supply they need, I am calculating in voltage or amps, i am a donut sorry

Well a in my house:
Kettle 3kw
fridge 0.2kw
hair-dryer 2.8kw
oven 4kw
halagon flood light 0.5kw
TV + skybox 0.3KW (32inch)
shower 9.8kw
boiler 0.1kw

Just an idea

 

[Adam_151]

I think we need to go back to the begininng with this one...

Where is this supply comming from, if its an existing premsies then is there enough spare capacity for the addition?

If its a cabinet on the boundry for the supply authority equipment, then have you tried getting a quote for s supply directly to the property?

This installation really needs to be designed properly, the house doesn't pose too many uncertainties, if its going to be a standard 1 family dwelling with gas central heating (is it?)... any electric shower?, then you can easily enough put a fiqure on demand, but farm buildings are a different matter and demand will depend on intended use

As others have said, there is no way 16mm will be adequate

 

[ricicle]

There is no way you can even begin to take on a job of this nature without specialist help. You need to consult an Electrician or possibly DNO as they will specify cable size/route/depth/type/length as it will be their liability when all is done.

 

[mfarrow]

These days for a typical house DNOs will only allow a maximum of 20kVA being requested - i.e. with a cutout of about 80A.

If you do the calcs, this works out at requiring a 120mm² cable for a 200m run, assuming you're feeding some lights on the end of this somewhere (?).

I would go to the DNO and ask them for a quote, they might surprise you.

 

[ban-all-sheds]

You'll need to decide what maximum voltage drop you want to see at the incomer to your CU, because you'll need some left for the final circuits, but assuming that you want to go for 2-3%, and your maximum load in the range 60 - 80A then you're looking at 0.58 - 0.29 mV/A/m, so 95mm² - 185mm² for copper cable, 150mm² - 300mm² for aluminium.

Figures subject to verification by someone with a proper cable calculator, but basically trying to supply an entire house by transmitting LV over hundreds of metres is a non-starter.

 

[iamagirlremember]

Hi thanks all very much for your advice.

I think i will speak to this DNO, but please can you tell me what it stands for!!

Again many thanks

 

[bernardgreen]

My partner has just brought some land and eventually wants to build a property on there (6 bed house-hopefully ) plus farm bulidings, possible chicken/goat shed.

As it is a new build you and he are going to have to have all services laid on to the site by the supply organisations. water, sewage, telephone and electricity and possibly gas.

Cost of a new supply to a new site is often much lower than repairs / upgrades to an existing customer. ( new customer, = more sales = more income )

Been there ( self build 1980 ) and believe me the cost of a new electrical supply is trivial compared to the overall build costs.

DNO = District Network Operator The company that maintains the supply network of cables to houses. They are NOT the people you buy electricity from.