Grounding jumper connected to the door of the distribution box
The green screw is the main bonding jumper connecting the grounded busbar to the enclosure. Here's why it matters: Static discharge: Metal doors can build up static charge, especially in high-voltage environments. The smaller bare copper conductor on the left is the equipment grounding conductor providing bonding. In Mike Holts video, someone asked him if the grounding electrode conductor can be connected directly to the X0 terminal of a separately derived system (transformer secondary). 26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used.
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