Gauge wire for 30v/1.5A umbilical cable?

[thuanth43]

I’m planning to build an umbilical cable to connect my separate power supply to amplifier section. The supply outputs 30Vdc, 1.5A peak. Cable length is maximum 1 meter (3ft). Which gauge wire should I aim for? I have rolls of 24awg PVC wires that I’m thinking of using.

Thanks

 

[amplidude]

That would yield a 0.84 percent voltage drop

 

[altec9440]

you will find a calculator here :
Calcul de section des cables electriques

don't forget that for a distance of 1m, you have two meters wire..

 

[indianajo]

I'd use 20 or 18 gauge. 18 zip cord is stocked in hardware stores, you wouldn't have to buy a whole roll. Also used appliance cords are often that gauge. When I salvage the speaker drivers out of a projection tv on the curb, I usually cut the cord, too. bought my first 250' roll of 18 ga zip cord last week, need two 80' runs for auxillary speakers in buildings.

 

[Mark Tillotson]

Wire gauges are clumsy when you want to calculate anything as you need to look up in tables, whereas if you always use cross-sectional area you can calculate cables losses directly using the resistivity of copper (1.68e-8 from memory!)

 

[thuanth43]

I'd use 20 or 18 gauge. 18 zip cord is stocked in hardware stores, you wouldn't have to buy a whole roll. Also used appliance cords are often that gauge. When I salvage the speaker drivers out of a projection tv on the curb, I usually cut the cord, too. bought my first 250' roll of 18 ga zip cord last week, need two 80' runs for auxillary speakers in buildings.

I have rolls of 18awg but unfortunately the connector is too small to accommodate 4 of them.

 

[thuanth43]

That would yield a 0.84 percent voltage drop

That’s actually not that bad. I might make the cables a bit shorter (60cm). Thanks for your calculation.

 

[amplidude]

My calculation is a bit off, its actually twice as much, I used 1 meter in formula, and theres two