3Com 2900 manual Where a Grounding Conductor Can be Buried, Other Installation Sites

zThe PGND cables supplied with the 3Com Baseline Switch 2900 Family do not provide OT terminals at the ends connecting the grounding strip. You need to prepare proper OT terminals by yourself.

zThe fire main and lightning rod of a building are not suitable for grounding the switch. The PGND cable of the switch should be connected to the grounding device for the equipment room.

Where a Grounding Conductor Can be Buried

When there is no grounding strip, but an area with exposed earth is available nearby where a grounding conductor can be buried, hammer a 0.5 m (1.64 ft.) or longer angle iron or steel tube into the earth. The angle iron should have a dimension no less than 50 × 50 × 5 mm (1.97 × 1.97 × 0.20 in.) and the steel tube should have a wall thickness no less than 3.5 mm (0.14 in.) and be zinc-coated. Weld the yellow-green PGND cable to the angel iron or steel tube and treat the joint for corrosion protection.

Figure 3-12Ground the switch by burying the grounding conductor into the earth

(1) Grounding screw	(2)	PGND cable	(3) Earth
(4) Joint	(5)	Grounding conductor	(6) Switch rear panel

In Other Installation Sites

When the switch is AC-powered

For an AC-powered switch, if neither of the above-mentioned two conditions is available, ground the switch through the PE wire of the AC power supply. Make sure the PE wire is well connected to the ground at the power distribution room or AC transformer side, the switch PE terminal and the PE wire are well connected, and the three-wire input cable of the PGND cable is used for the power supply cable. If the PE wire of the AC power supply is not grounded at the power distribution room or AC transformer side, report the problem and make reconstructions.

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