16Figure 20 Connecting the grounding cable to the grounding strip(1) Grounding post (2) Grounding strip(3) Grounding cable (4) Hex nutGrounding the switch with a grounding conductor buried inthe earth groundIf 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 a minimum of 50 × 50 × 5 mm (1.97 × 1.97 × 0.20 in). Thesteel tube must be zinc-coated and its wall thickness must be a minimum of 3.5 mm (0.14 in).Weld the yellow-green grounding cable to the angel iron or steel tube and treat the joint for corrosionprotection.Figure 21 Grounding the switch by burying the grounding conductor into the earth ground(1) Grounding screw (2) Grounding cable (3) Earth(4) Joint (5) Grounding conductor (6) Chassis rear panelGrounding the switch by using the AC power cordIf the installation site has no grounding strips or earth ground, you ground an AC-powered switchthrough the PE wire of the power cord. Make sure of the following information:• The power cord has a PE terminal.• The ground contact in the power outlet is securely connected to the ground in the powerdistribution room or on the AC transformer side.
