Ground (or ground)-deliberately ground something. This is usually done to dissipate static charges and lightning energy, because unless you get high voltage and high current, the earth is a bad electrical conductor.
Adhesion is the intentional interconnection of conductive objects in order to tie them on the same potential plane. This is where people are confused about grounding/grounding. The purpose of bonding is to ensure that if the power circuit fails on the enclosure or the device, there will be a low impedance path back to the power source, so that the upstream overcurrent device will quickly run and clear the fault, and then any operator is seriously injured. /Kill or catch fire.
The ground fault protection is multi-functional, and I will stay in the low voltage (<600V) field. A version, usually seen in most locations where low voltage (220 or 120 volts to ground) is used, usually a 5-7 mA device, designed to ensure that the current from the hot wire returns to the neutral point/ground conductor ; This is to protect people from electric shock again when in a low resistance state. Another version is "Equipment Ground Fault Protection", which is used for resistance heating or irrigation equipment. The trip level here is about 30 mA, and more used to prevent fire. The final version of ground fault protection is when the ground/neutral voltage exceeds 150 volts (eg 380Y/220, 480Y/277 are a few typical examples), and-at least in the United States And Canada-the incoming main circuit interruption device is at least 1000 amps (although this is not a bad idea at a lower level, it is not mandatory); here is used to ensure that downstream faults are cleared to avoid fire or occurrence "Burn-out" event, because there is enough residual voltage, the arc can continue to run, not just self-extinguishing.
In the medium voltage and high voltage areas, ground fault protection is actually just a protective relay, which monitors the phase current and operates under unbalanced conditions, usually determined by the system designer.