Correct wire gauge for 24V 12.5A

Thread Starter

Coreysmith

Joined Nov 1, 2022
4
Hi, this is my first post so, please advise if something is wrong.

I have 4 x 300W power supplies to wire up to 4 dev boards to drive some speakers.

my plan is to run from one plug to function box then out to the 4 power supplies. They are 24V 12.5A output. Each power supply goes to one dev board. My issue is connecting from the power supply output to the board. I need to use a 5.2mm dc jack but the ones we have can only take very small wires, barely fits 2 x 1mm2 with some force. But to my understanding I need to use 2.5mm2 to handle the 12.5A current.

Am I able to use thinner wire?
Are there different jacks I could use without using the quick connect screw type ones?

Thanks in advance.
 

crutschow

Joined Mar 14, 2008
31,126
What are the length of the wires, and how much voltage drop can you tolerate due to the current?

What is 2 x 1mm2 wire?
I'm not familiar with that format.
 

MrChips

Joined Oct 2, 2009
27,686
Personally, I would opt for 14 AWG (2.5mm^2) or 12 AWG (4mm^2).
You will have to change the connector or make an adapter (or splice) to bridge between the two size cables. We talked about different types of splices in another thread.
 

crutschow

Joined Mar 14, 2008
31,126
Another possible way to use large stranded wire with a small connector opening is to cut some of the strands of the wire at the connector until it fits.
That will have negligible effect on the total wire resistance.
 

Thread Starter

Coreysmith

Joined Nov 1, 2022
4
Another possible way to use large stranded wire with a small connector opening is to cut some of the strands of the wire at the connector until it fits.
That will have negligible effect on the total wire resistance.
Unfortunately the problem is not just soldering it to the connector, but the wire doesn’t actually fit through the sheath (plastic cover).
 

Thread Starter

Coreysmith

Joined Nov 1, 2022
4
Personally, I would opt for 14 AWG (2.5mm^2) or 12 AWG (4mm^2).
You will have to change the connector or make an adapter (or splice) to bridge between the two size cables. We talked about different types of splices in another thread.
After looking up the NEC ratings from the comment above, it appears I can use AWG 16. I’m still not convinced it will fit, but AWG14 won’t fit. It’s not the conductor size that’s the issue. It’s the cable diameters that I cannot get through the plastic cover of the dc jack.
 

Janis59

Joined Aug 21, 2017
1,537
1) For loudspeakers stays another table of cross sections as there the limiting factor is saound quality not the heat dissipation.
2) There where heat dissipation is limiting the thumb-rule in the transormers is 2 A/mm2 - bobbin enen is not warm, 3 A/mm2 bobbin is notable warm but may keep in the hand, 4 A/mm2 - bobbin is notable warmer than 120 C and may reach even 150 C, but for short-time repeating load it is negotiable, yet not for each type of wire insulation. 5 A/mm2 - 120 C in about minute and then demanding at least hour to cool down. If not stop the process, melt in about 5-10 minutes.
3) For stand-alone cabling where more than one line is close parallel. In the wall mured about 10 -12A/mm2, in air hanging free about 8-10. If wire is alone, non-insulated, hanging free in air - up to 20 A/mm2.
 
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