Piece wires : Temperature

puteh30

hye... i new user (forumer)... help me....

1) i have 3- 4 piece wire (copper/ iron)... i dont know AWG for piece wire... no label... the length of wire is 1 foot... how to know / measure / calculate the maximum voltage, maximum current, maximum temperature, thickness, type of metal for piece wire.



2) temperature relation / propotional - voltage
- current
-conductivity
-resistivity

*formula / definition

davenn

current capability of a wire is primarily proportional to its diameter (thickness) ( and somewhat to the type of wire... copper, aluminium etc) you need to find out what you wire is what its made of, what its size is AWG etc.
its resistance is also dependant on what its is ... copper etc and thickness
known cables will have data sheets that will state that info along with its resistance in Ohms / metre(foot) km(mile) etc

we cant help you without that information

cheers
Dave

MATLABdude

If you have a pair of calipers (or better yet, micrometers), measure the diameter of a STRIPPED portion, and then read it off the chart (this will be a little problematic if the wire is stranded, but not impossibly so):
http://en.wikipedia.org/wiki/American_wire_gauge

Note that the information is rule of thumb ONLY. Temperature rating, maximum voltage, and resistance will depend on the insulation used (if any) and the history of the piece (i.e. if it's severely kinked or cut-up in certain areas, the resistance will increase).

For something where this really matters, get some new pieces of wire. They're pennies per feet.

EDIT: and pursuant to my point about the 'history' of the piece, this will affect its current-carrying capability.

vk6kro

One way to measure the diameter of a wire is to wind the wire around a cylinder (like an AA battery) so that the turns are right up close to each other.
Then measure one inch or one centimeter along the coil and count how many turns of wire are in that distance. From this, it is easy to work out the diameter of the wire.

The most common wire is probably copper. This has an orange-red colour and bends easy.

Iron wire is attracted to a magnet and it is harder to bend than copper.

Aluminum wire is silvery-white when cut but it turns to s smoky white as it oxodises.

Another type you may come across is Nichrome wire. This is very springy and will not wind into a coil easily. It has a very high resistivity and so quite a short piece of this wire has a lot more resistance than a similar piece of copper wire.

Here is a list of resistivities which will give you a comparison between different materials as conductors.
http://en.wikipedia.org/wiki/Resistivity

Also see the wire table given above in a previous post.
http://en.wikipedia.org/wiki/American_wire_gauge

puteh30

how do know the size of AWG? wire made (material) ???

puteh30

help me.... this example piece wire


[img=http://img192.imageshack.us/img192/7638/dscn5043x.th.jpg]
[img=http://img4.imageshack.us/img4/2913/dscn5051f.th.jpg]

puteh30

current-carrying capability means ???

puteh30

wire above? iron or aluminum?

NascentOxygen

magnet?

NascentOxygen

amps

NascentOxygen

yellow=copper
black = ??????

sophiecentaur

= charred?

puteh30

hye... i new user (forumer)... help me....

1) i have 3- 4 piece wire (i dont no type of metal piece wire)... i dont know AWG for piece wire... no label... the length of wire is 1 foot... how to know / measure / calculate the maximum voltage, maximum current, maximum temperature, thickness...



2) temperature relation / propotional with

- voltage
- current
-conductivity
-resistivity


*pls give formula / definition....


http://img192.imageshack.us/img192/7...cn5043x.th.jpg
http://img4.imageshack.us/img4/2913/dscn5051f.th.jpg

puteh30

help me....

berkeman

Welcome to the PF. What is the context of your question? You are trying to figure out the maximum ratings for these wires, given only 1 foot samples? What other information do you have? What is the application for the wire?

You use standard wire tables and/or the manufacturer's datasheet to figure those things out.

http://www.powerstream.com/Wire_Size.htm

.

puteh30

What other information need i have? What is the application for the wire? pls help me

NascentOxygen

No one knows. We need you to tell us about it.

Did you salvage it from a space vehicle?