Automation Hat 24v and current

First of all, I’m not an electrician, which you will guess if you continue reading my question…
If I got this right I’m going to connect the 24v supply to my “24v external device” and the ground-wire to the Automation Hat “nr 2 ground” and connect a wire from output 2 (sinking output NOT relay) to the ground of my “24v external device”?
About “nr 2 ground”, at the same time I’m running two “5V internal devices” wired to 5V on the Automation Hat and using “nr 1 ground and nr 3 ground”… Is this right?

Another question is, what happens if my “24v external device” are using more than 500mA, will it burn/over heat or just “limit it self” to not using more than 500mA?

  • I’m reading about the Darlinton Array that supplies the outputs can only sink up to 500mA and what it means…

In summary, can I connect 5V and 24V to the ground at the same time (is the ground the same for all three connection points)?