cable formula?

[dave_p_r_b]

Is there a formula for calculating the size of cable needed given power, current, length- etc?

I\\\'m _not_ going to use it to choose cable, I\\\'ll leave that to an expert, but am curious....

Also, typically what is the max power rating of a single oven, no hob?

 

[Albert]

Is there a formula for calculating the size of cable needed given power, current, length- etc?
Also, typically what is the max power rating of a single oven, no hob?

The answer is yes, but what you are asking is to explain to you a big part of course 2360 (electrical installations) in few sentences. It is not only using a formula it is about understanding the environmental conditions, how many cables, what type of cables, what is the method you going to run the cable/s and using the correct recommended factors and very important follow the regulations.
The value you are looking for is (normally indicated on the unit, if it is an old one and the plate or sticker was lost or removed, you should eighter call the manufactorer and find out or find this model in one of the shopes.

Do not connect it to the power before you have this info. and you did confirm with someone in the proffesion that it is safe.

 

[sterose]

As said, the forumlas would be pretty complex.

For the layman however, just err on the side of caution and use a cable with a slightly bigger rating.

 

[Sym]

Now i do not want to put down any sparkys here, but electricians are not mathematicians (i am sure they will admit) and so, although the actual formula may be fairly complicated, the one they use is not so complex, in fact it is more a table and rules of thumb they apply together with a 'lets add a bit to be safe' factor. There are on this board electrical and electronic engineers who could give you the full ins and outs of material science etc if you want.

 

[Big_Spark]

Now i do not want to put down any sparkys here, but electricians are not mathematicians (i am sure they will admit) and so, although the actual formula may be fairly complicated, the one they use is not so complex, in fact it is more a table and rules of thumb they apply together with a 'lets add a bit to be safe' factor. There are on this board electrical and electronic engineers who could give you the full ins and outs of material science etc if you want.

Sym, the reason a lot of electricians don't do the calculations all the time is simply experience. After a while you know the load a given cable will deliver a given distance, and on most installations, this has been worked out prior to work starting by engineers.

If you have maths knowledge then the formula are not complicated, you are correct, however actually understanding what the different parts of that formula are and what the answer means is another matter.

I am sure that you could do some calculations in Nuclear Physics, but would you understand the answer?

There is an old saying " A little knowledge is a dangerous thing", this is very true. If you get DIYers trying to do complicated cable calcs without fully understanding the theory behind it, then there is a real danger that they will get it wrong, and then you potentially have a dangerous situation.

There are certain things that DIYers should leave to the professionals

 

[Sym]

FWL I agree totally

 

[dave_p_r_b]

hi,
thanks all.

My brother in law will do the connection... he is an electrician.
as i said

I'm _not_ going to use it to choose cable, I'll leave that to an expert, but am curious....

The oven is new, so the information on max power consumption is available. The reason I ask about typical values is not so I can guess the cross-sectional area of the cable, but to see if an oven of only 2kW (which I have bought), is common (and capable of melting butter).

I was merely interested in the sums.

 

[Albert]

I beleive that we agree on this one for a change...

 

[IanDB]

I think most ovens are up to about 3kW max. It's the hob that really draws the power. If you think about it, if you took a 2kW fire and put it in a small metal box how long would it take for the butter to melt?

 

[dave_p_r_b]

hi,

thank you for a straight answer.

I did Actually come up with the concept of a 2 bar fire in the oven... but, then i wondered if I could cook a turkey....
.. dont ask.

Thank you again.
David.

 

[Big_Spark]

I did Actually come up with the concept of a 2 bar fire in the oven... but, then i wondered if I could cook a turkey....
.. dont ask.
.

Well a two bar fire in a metal box would cook anything..given enough time

 

[securespark]

Just make sure you bung your bird (I mean the turkey, silly!) in the oven now to guarantee readiness for Dec 25 2004!

 

[dave_p_r_b]

i should have been suspicious when i saw the oven ONLY has a "slow cook" setting on the dial...

 

[securespark]

 

[Big_Spark]

i should have been suspicious when i saw the oven ONLY has a "slow cook" setting on the dial...

I think that refers to the female component of the cooking system