Very Useful Info ( Must Read )

[AbecEngineering]

how much wires can handle

strands___size____amps
26............3mm......10
41............4mm......20
94............5mm......40
182...........6mm......60
779...........14mm....160

Relays ( what the numbers mean on them )

30 - battery positive
80 - earth
86 - switch
87 - load

Engine displacement volume

___TDC___
◄-Bore-►
↑
Stroke
↓
___BDC___

 

[Engineeringtech]

How much current a wire can handle depends on whether it is bundled with other wires, the thermal dissipation, the frequency of the current, etc. You don't want the wire insulation to melt. Fusing current is a totally different matter. The link below shows fusing currents for American wire gauges.

http://www.powerstream.com/wire-fusing-currents.htm