I am building a prototype rig. It includes: 1) A "naked" 24/48 V motion control evaluation board. 2) A I=3.6 A stepper motor. 3) A power supply.
I wired up the motor to the board with four wires (A-, A+, B-, B+). I wired the board to the power supply: source (24 V) and ground wires.
The power supply allows to set both voltage and current. I am planning to set the power supply voltage to 24 V, not sure about current. By default it's at I=0.1 A, but I guess I might need at least 1 A to activate the stepper.
Now, a pessimistic assessment of the skin resistance is 500 Ohms (Wikipedia article on electric shocks). At 24 V, this would give a through current of 48 mA, causing heart fibrillation, breathing difficulties and inability to let go of the wire -- not cool.
How do I play it safe?