The function of grounding the distribution box door
The grounding system provides a low-impedance path for fault current and limits the voltage rise on the normally non-current-carrying metallic components of the electrical distribution system. Why ground the door if the cabinet body's already grounded? Imagine this scenario: You're racing to finish wiring up a production line. Then your supervisor walks by and points at the ungrounded door— "Add a wire to that!" Ugh. 26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used. When inspecting the interior of a stainless steel outdoor electrical box distribution box, pay attention to the copper or tin-plated terminals on the base plate or side walls. A correct understanding of the basic principles involved will help him/her to avoid mistakes in grounding system design.
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