31CAUTION:Hammer a 0.5 m (1.64 ft) or longer angle iron or steel tube into the earth. The angle iron should have adimension no less than 50 × 50 × 5 mm (1.97 × 1.97 × 0.20 in) and the steel tube should have a wallthickness no less than 3.5 mm (0.14 in) and be zinc-coated.Figure 41 Ground the switch by burying the grounding conductor into the earth123456(1) Grounding screw (2) grounding cable (3) Earth ground(4) Joint (5) Grounding conductor (6) Switch rear panelGrounding the switch with the PE wire of an AC power supplyIf the switch is AC powered and no grounding strip or area with exposed earth is available at theinstallation site, you can ground the switch through the PE wire of the AC power supply, as shown inFigure 42.CAUTION:• Make sure that the AC power supply uses a three-wire cable with a protection wire, and the PE wire ofthe AC power supply is well grounded at the power distribution room or AC power supply transformerside.• Make sure that the PE connector on the switch is well connected to the PE wire of the AC power supply.• If the PE wire of the AC power supply is not grounded at the power distribution room or AC transformerside, report the problem and make reconstructions.
