Grounding the switch with a grounding conductor buried in the earth ground
If the installation site has no grounding strips, but earth ground is available, hammer a 0.5 m (1.64 ft) or longer angle iron or steel tube into the earth ground to serve as a grounding conductor.
The dimensions of the angle iron must be at least 50 × 50 × 5 mm (1.97 × 1.97 × 0.20 in). The steel tube must be zinc-coated and its wall thickness must be at least 3.5 mm (0.14 in).
Weld the yellow-green grounding cable to the angel iron or steel tube and treat the joint for corrosion protection.
Figure 14: Grounding the switch by burying the grounding conductor into the earth ground
(1) Grounding screw | (2) Grounding cable | (3) Earth ground |
(4) Joint | (5) Grounding conductor | (6) Chassis rear panel |