Dahua SG4028 Quick Start Manual page 14

There is a GND screw on the device cover board for the GND cable, which is called enclosure GND.
Connect one end of the GND cable with the cold-pressed terminal, and then fix it on the enclosure
GND with the GND screw. The other end of the GND cable should be reliably connected to the
ground.
The sectional area of the GND cable should be more than 2.5 mm 2 , and the GND resistance shall be
less than 4 Ω.
Figure 3-8 GND terminal
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