Electrical Question's, re: sizing Options

[76-914]

Does anyone have a table that shows the amp limits and permissible lengths for various wire sizes? What is std practice for sizing fuses? Is the fuse sized by wire limits or demand? Does a soldered connection add to resistance? (IMG:style_emoticons/default/confused24.gif)

[Tom]

The big difference between using a smaller wire for power in an automotive circuit is the voltage drop in the circuit. The longer the run, the greater the voltage drop for a particular size wire. Most wiring tables use a 2% voltage drop in their formula for determining minimum wire size, some use a 5% voltage drop.. A step up in size will improve the performance of the circuit, = less voltage drop. Ever wonder where that voltage goes? It is dissipated as heat along the length of the wire. Put too small a wire in and the wire's ability to dissipate the heat will result in a fire.
Also something that should be considered in selecting wiring is where the wire will be used. If in the engine bay, you should upgrade to a wire that handles greater heat and exposure to oils and gas, such as GXL coded wire. Good to 257 degrees and is resistant to oils and gas.
Tom