Earth wiring

Thunder Laser connected Earth wiring to every machine cabinet panel with electrical parts.

here's what happens with no ground wire,

If you touch the machine case when it's electrified then you might complete a path to the ground, and all the current is going through you. But there's not nearly enough electrical current flowing through the circuit breaker, so it won't trip off. There's a good chance that you'll be electrocuted.

Now here's what happens when we ground the whole machine, and that ground wire goes back to the neutral bus bar in the electrical panel.