The ground wire of the distribution box is not grounded
Attach a ground wire from one of the threaded studs (A) at the bottom of the housing, to the mounting plate (B). 26 mm 2 (10 AWG) ground wire must be used, and in all other markets a 6 mm 2 must be used. If you've ever found yourself scratching your head over whether that metal door on your distribution cabinet really needs a grounding wire, you're not alone. Preparation: First, you need to prepare some necessary tools, including grounding wire, grounding rod, voltmeter, insulating gloves and insulating tools. We can see the box is mounted to the drywall with simple sheet metal mounting tabs, and based on the hack with the two supply conductors, we can be almost certain that box isn't actually grounded. I don't see one on the main panel however The neutral bus is bonded (green screw) to the enclosure.
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