Trevor Rymell
Member
Sorry for asking these dumb questions but could I please check if the following is correct about cables?
1. For any given cable and given thickness of insulation (assuming constant ambient temp, humidity and air pressure conditions etc), it's the cross sectional area of the copper and NOT the number of strands that determine its continuous current carrying capacity. I know that in practice the thickness and type of insulation counts as does the copper composition, resistance and probably a load of other things.
So for example, a single strand of copper with a 2mm cross sectional area will carry the same current as a 40 strand with a 2mm cross sectional area. The only difference would be the mechanical durability and flexibility.
2. A given cable carries roughly twice as much AC current as DC. Is there a formula to calculate this?
3. Is there a way to calculate the AC or DC continuous current capacity if I know the number and thickness of the strands of a given cable? Manufacturers labels often given the voltage but not current capacity.
Thanks in advance
Trevor
1. For any given cable and given thickness of insulation (assuming constant ambient temp, humidity and air pressure conditions etc), it's the cross sectional area of the copper and NOT the number of strands that determine its continuous current carrying capacity. I know that in practice the thickness and type of insulation counts as does the copper composition, resistance and probably a load of other things.
So for example, a single strand of copper with a 2mm cross sectional area will carry the same current as a 40 strand with a 2mm cross sectional area. The only difference would be the mechanical durability and flexibility.
2. A given cable carries roughly twice as much AC current as DC. Is there a formula to calculate this?
3. Is there a way to calculate the AC or DC continuous current capacity if I know the number and thickness of the strands of a given cable? Manufacturers labels often given the voltage but not current capacity.
Thanks in advance
Trevor