The electric box is connected to the ground wire of Line 5. If the electrical equipment is close to the ground of Line 5 and the line diameter is sufficient, if the environment is not good, such as electric wells, such as small motors, there is no need to repeat grounding.
Large motors and the like should be done, because repeated grounding is to prevent the ground wire from failing.
The significance of equipotential of medical equipment, toilet and repeated grounding of center console in decoration is the same.