swa sizing

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dan.

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sorry for yet another post,got a few jobs coming through at the mo.

im doing a garage conversion soon making it into an office, im rewiring it completly with a lighting circuit for 10 downlights ,32amp ring and a 20amp circuit for 2 1500w heaters i get this lot to 50amps total load with a little bit of diversity on the ring circuit.now my question is will i get away with putting in 6mm swa or does it need 10mm ?the run is about 20m maybe less and will be run on the surface of a wall. thanks

 

Badger

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I have a customer who requires a armoured supply putting in t65 metres from the house to their gate at the end of the driveway

whats the calculation for the size of armoured id need to calc volt drop. it will be no more then 10 amps supplied to gate.

cheers badger

 

Badger

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sorry for yet another post,got a few jobs coming through at the mo.im doing a garage conversion soon making it into an office, im rewiring it completly with a lighting circuit for 10 downlights ,32amp ring and a 20amp circuit for 2 1500w heaters i get this lot to 50amps total load with a little bit of diversity on the ring circuit.now my question is will i get away with putting in 6mm swa or does it need 10mm ?the run is about 20m maybe less and will be run on the surface of a wall. thanks
i would say 10 mm to be on the safe side with that loading

 

dan.

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didnt know there was a difference swa is swa??

im intending using a 50amp mcb if that makes a difference

 

paulh

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didnt know there was a difference swa is swa??im intending using a 50amp mcb if that makes a difference
Sorry if this is condecending don't mean too, but have you looked at the regs tables for current carrying capacity of cables?. What difference exactly do you think a 50amp mcb will make, will it save a 6mm swa cable? all the answers to these questions are in the tables.

 

dan.

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no offense taken. i thought 10mm straight away its only because i went on the tlc site to check for volt drop that 6mm cropped up.6mm would be at its max and theres no room for overloading either.back to original plan 10mm cheers guys.no a 50amp mcb wouldnt save a 6mm cable.

 

extension15

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no offense taken. i thought 10mm straight away its only because i went on the tlc site to check for volt drop that 6mm cropped up.6mm would be at its max and theres no room for overloading either.back to original plan 10mm cheers guys.no a 50amp mcb wouldnt save a 6mm cable.
10mm would be install choice, for the sake of the extra cost..

:D

 
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sorry for yet another post,got a few jobs coming through at the mo.im doing a garage conversion soon making it into an office, im rewiring it completly with a lighting circuit for 10 downlights ,32amp ring and a 20amp circuit for 2 1500w heaters i get this lot to 50amps total load with a little bit of diversity on the ring circuit.now my question is will i get away with putting in 6mm swa or does it need 10mm ?the run is about 20m maybe less and will be run on the surface of a wall. thanks
OK..

so maybe I'm being a bit fick here but 50A for a garage supply..

conversion to office??? :eek: ? :|

How big is this garage???

lights:

10 downlights, 50watt? maybe = 500watt = 2.17A [@ 66% diversity 1.44A]

I assume this is a 6A MCB?

2 x 1500watt heater, 3000w = 13.04A [diversity 100% of 10a + 50% of rest

= 11.52A]

I would stick them on a 16A radial!

Ring ciruit.... 32A why? is 7360watts of power going to be used...

(remembering heating has already been taken account of?)

what is going to be plugged in that is taking 7.36Kwatts?????

if its mostly computer & IT type equipment I would guess it is not going to be any more that 13A max ?

I would probably put socket on a 16A or 20A MCB?

so absoulte MAX 20+16+6 = 42A

or allowing a bit of diveristy.. more realistic values probably ... approx 28 - 29Amp.,

I just cannont see your requirment or 50amp???

:)

 

dan.

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i know it sounds over kill but they want to use it as an office/workshop and they want 8 double sockets in there room is 11ft by 23ft.

heating is set for 2 1.kw heaters but i reckon in middle of winter that wont be enough so im over speccing so if needs be they can plug more heat in.

 

The Godfather

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i know it sounds over kill but they want to use it as an office/workshop and they want 8 double sockets in there room is 11ft by 23ft.heating is set for 2 1.kw heaters but i reckon in middle of winter that wont be enough so im over speccing so if needs be they can plug more heat in.
That's is not enough heating Dan, install the 10mm SWA..

Alterations/additional needs are covered.

Don

 

dan.

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aye im gonna use 10mm. was originally, its just the TLC site with its volt drop calculator that got me thinking.ill not bother in future and just use good old calculations ; \

 
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i know it sounds over kill but they want to use it as an office/workshop and they want 8 double sockets in there room is 11ft by 23ft.heating is set for 2 1.kw heaters but i reckon in middle of winter that wont be enough so im over speccing so if needs be they can plug more heat in.
IMHO you are very much over specifing... 50A?? for approx 250sq ft of floor space?

taking into consideration many a whole house is still only on a 60A main fuse.. or more common 80A..

& thats for all your cookers / showers / imm heaters / electric fires etc.. etc..

even if things do turn out cold..

There are plenty of lower power type heaters.. e.g. some oil filled appliances..

take longer to heat up but once warm generate a fair bit of background heat..

that can be left of continuous or set up on a timer to take the chill off a cold morning!

or even there are some good convector type heaters 750watt.

http://www.dimplex.co.uk/products/domestic_heating/portable_heating/convector_heaters/latitude_range/index.htm

Unless you have some really unusual workshop type equipment?

(had a customer who did ceramics & glass work.. needed a miniature Kiln for firing & baking the work!! :_| )

Still cant see you being anywhere near 50A? :eek: :|

lights: 6A

10 down lights, 50watt? maybe = 500watt = 2.17A?

heating: 16A

2 x 1500watt heater, 3000w, 13.04A?

Ring ciruit.... 32A? (reckon 20A would be big enough)

plug in 2 x 750watt extra heaters... 6.5amps

leaves 13.5A (3kw) of other power plugged in?

So assuming everything is running full wack NO diversity..

20+16+6=42amps

But your lights are nowhere near 6A

your 2 x 1.5k heaters are NOT 16A

more likely 30A tops IHO?

 
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she does a bit of pottery on the weekends:D
so a 3k plug in kiln oven type thing?

which would also generate some heat in the room?

alleviating the need for too much other additional heat possibly? ;)

Or are we talking a bigger rating hard wired bigger oven?

Has the room had any insulation or building improvements done to it?

 

dan.

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yeah 100mm insulation all round.im doing alot of the work with my old man.itll be better than the house he lives in!!calculated it needs 3000watts of heating to maintain 21 degrees

 
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