thick wire

[duffman]

Iu was wondering, what happens if you use a gauge of wire that is too big for a project. People often use water pipes as a model system for wire, but having a big pipe doesnt make water flow any slower.

 

[Phasor]

Never Too Big :lol: The effect of increasing the size of your wires, is lowering the voltage drop (which is usually a good thing), however it does increase the cost of your project, and the size of the box you put it in :wink:

You can, however make your wires too small, to a point where they overheat and melt.

 

[gerty]

What Phasor said, plus too large a wire is difficult to terminate in small areas :cry:

 

[Oznog]

A wire has to meet at least two specifications:
1. The wire should be thick enough not to reach a critical temp which would overheat the particular type of insultion it has. The degree of airflow around the wire (inside a harness vs free air) and the ambient temp change the ratings somewhat. This property is only based on current and is independent of wire length.
2. The entire length of wire should have a total resistance which is acceptable to your application. Long runs of automotive wire can drop 12V to 10V by the time it reaches the load, even though the wire's thermal handling specification has been met.

Thick wire is expensive and troublesome to connect, this is why people usually size to the the minimum necessary plus a reasonable safety factor.

 

[Styx]

Never Too Big :lol: The effect of increasing the size of your wires, is lowering the voltage drop (which is usually a good thing), however it does increase the cost of your project, and the size of the box you put it in :wink:

You can, however make your wires too small, to a point where they overheat and melt.

I dissagree with this for only a couple of points. Thick wire is always good - less resistance and all and better handling of current. But if you needed twisted pair then the flux linkage gets worse with increase diameter of cable. A tradeoff must be made between less resistance & inductance due to the cable and flux linkage due to twisting

Depending on your application bend radius might be a problem. Thicker cable tend to have bigger bend radius

And also if you are transmitting power at a decent frequecy you have skin-effect to concider if the cable is too think or too thin

 

[duffman]

Say I needed to have a wire that was considerably longer than the rest be uase it had to reach a switch that was at the far end of a casing, My main concern would be to make sure the wire doesn't curl up, and that the wire is thick?

 

[Phasor]

My main concern would be to make sure the wire doesn't curl up, and that the wire is thick?

Does it matter if your wire curls up? This depends on the application.