Looking up table for wire diameter selection

Dear cnpower,

The table shrank when you sent it. If it's on-line could you please provide a link to the table>

Thanks

Orpheuse

try to use excel to carry out it. as follow:

copy formula into yours. can it can calculate automatically. and get all datas what you want.

Hi cnpower.

I think it works in excel as you suggested.

Thanks

congratulation. and see more how to select current density at beneth.

I, too, tried to save it. When I try to enlarge it, the numbers get all blurry and can't be read.

Try to put it at the bottom of your thread. Select "none" for your alignment and drag it to the bottom. That way, if it gets resized, it will take up the whole width of the frame (I hope).

its a long time ago I got that tabe. I forget where it from. but you can refer this excel program for your data. hope this helps.

Nope, problem is that if you paste it here, it becomes an image and can't be copied into an Excel except as another image.

I would be careful with such a table because of some reasons. In applications where the wire diameter is a sensible data you mostly have to bear in mind some environmental conditions - otherwise anyway a thumb rule mostly is quite enough.

1. The allowed wire temperature rise is determined by the diameter.

2. The temperature is determined by the wire`s isolation which is extremely different between PVC and Silicon or even Teflon,

3. The temperature is also influenced by the number of wires laying together, which is further dependant on free-air or cable-channel wiring.

Thanks, cnpower, for your input, but - as with every tool - you have to know what for it is and where the limits are.

Regards Uwe

you are right.

how to select section area depends on temperature at all. thats why several current density values give out. different condition needs different density, for example, normal condition, we use 2A/mm². pulse condition we can choice 3A or 4A, so that you can have another wire diameter. its only reference.

I mean type the formula I listed into your function box. so that you can get the result as same as the table.

Pi = 3.14. you can use 3.14 replace pi symbol. and then multiply current density to get current value'

sorry not make clear at first.

Yup, I guess my brain wasn't firing on all cylinders!

I got it to work alright. Thanks.

congratulation.

Now let talk about how to select current density of a wire. In spite of the density depending on many conditions like temperature, but people still find out many short cut way to calculate it approximately in practice. for example, if the section area of a wire is under 10mm², multiply it by 5 and 100 by 2 etc. show as follow table.

made of aluminum. if the wire in tube, multiply by 0.8. if temperature is higher than 35 degree then x o.9 again.

I think it Will help you with your practice work.

Do you have any good method for it?

How do you evaluate the wire in practice and select them?

share your experience with us, ok?

I think different countries has different method.