wires hot to touch

I am connecting wires from power box to black box and they feel hot. Why

 

I have checked with a volt meter that the output from the yellow and black wires is 24 volt. And that the wires have not been reversed. When I plug in the adapter for the wires to the black box they start to get hot. It is set at 24 volts. I don't actually have the black box switched on. What am I doing wrong? Is this normal?



Thanks for any thoughts and help!!
Beth

 

I then connected hot yellow wire to v+ and neutral black wire to V- on the power box. I have then attached yellow to the right 24v side of the adapter and the black to the Gnd left side. I have double and triple checked everything is tight and to the best of my knowledge in the right place.
DROK 48V Power Supply, AC 110V/220V to DC 0-48V 10A 480W Buck Converter, Adjustable Variable LED Adapter Regulated 5V 12V 24V 30V 36V 48V Volt Voltage Transformer 10A Amp Charger for Lab CCTV Radio

This is where I got the black and yellow wire from Amazon:
18/4 AWG Shielded CNC Wire (50FT) — Flexible Stranded Shielded 18-Gauge 4-Conductor Cable for Stepper Motors, CNC Machines, NEMA Motors, VFD Spindles, CNC Routers, 3D Printers and more!

 

The power source I have is adjustable with the turn knob. I shows on a digital dial what the volts are set at.. I have changed it to have an output of 24 Volts. Am I missing something or misunderstanding how it works?

 

Please tell me I haven't damaged anything. I have only had it connected for a few seconds at a time. Never more than a minute.

 

Thank you!