Hello,

I am so wondered how manufactures know the capacity of a conductor. So, how manufactures do know the maximum voltage ratings, current ratings, and so?

Well, for example, I have purchased a metal strip or so and I will use it for something (which will be a path for an electric current to flow). But I am worrying that maybe some minutes, it will become hot or so.

So, how do I will know the maximum ratings of a one conductor?

Thanks.

 

Actually it is extremely simple. First start with the metal. It is usually copper, but it can be something else. Stick with copper though, for a specific gauge of wire you get a specific Ω/foot number. You also get how much current this wire can safely carry before showing signs of stress and damage from overheating.

Add the insulation characteristics such as temperature and breakdown voltage and you have a full set of specs for that strand of wire.

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

 

No~~~

I want to use a simple metal. Like metal strips. not wire.

Um, they only determine wires not other metals.

help?

 

You just made it unnecessarily complex. Metal has a specific Ω/meter³ (for you chaps who favor the other system), it is a physics property. Now if you just want to learn a bunch of math when you can use a simple table feel free. Have some headache medicine handy.

http://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity

 

For manufacturers, it's very simple. Get a piece of wire, pump some amps through it until it melts. They only have to do this a few times for each wire to know the rating.

 

Do you really want this guy melting wire with high currents?

 

For manufacturers, it's very simple. Get a piece of wire, pump some amps through it until it melts. They only have to do this a few times for each wire to know the rating.

That was in my mind.

 

Lightfire: Measure the strip of metal thickness and width. Convert that to "how big it would be if it was round". Then you can use standard charts if you are using copper or aluminum.

Other than that, you are going to be searching the internet for properties of metals.

 

This is a very general and very conservative estimation that is commonly used as a starting point..
For copper is roughly 1000 Amps per square inch (700 for aluminum)

Here is a better chart (for copper)
http://www.copper.org/applications/busbar/ampacity/busbar_ampacities.html