3com 2900 User Manual

 

3-6 

In many cases, standard 19-inch cabinets are not available. Therefore, switches are often placed on 
clean workbenches. To place the switch on a workbench, follow these steps: 

Place the switch with bottom up carefully, and then clean the round holes on the chassis bottom with dry 
cloth.  

Attach the rubber feet to the four round holes on the chassis bottom.  

Place the switch with upside up on the workbench.  

During the operation, you simply need to: 

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Make sure that the workbench is flat and sturdy. 

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Ensure good ventilation and a space of 10 cm (3.94 in.) around the chassis for heat dissipation.  

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Avoid heavy objects on the switch.  

 

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Correctly connecting the switch PGND cable is crucial to the lightning protection and 
electromagnetic susceptibility (EMS) of a switch. 

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The power receptacles and grounding terminals in this section are for illustration only. 

 

The power input end of the switch is connected with a noise filter, whose central ground is directly 
connected to the chassis, forming the so-called chassis ground (commonly known as PGND). This 
chassis ground must be securely connected to the earth so that the faradism and leakage electricity can 
be safely released to the earth, enhancing the EMS capability of the switch. 

When a grounding strip is available at the installation site, attach one end of the yellow-green PGND 
cable of the switch to the grounding screw on the grounding strip (the grounding screw and the 
grounding hole are on the rear panel of the switch and are marked with a grounding sign). To do this, 
follow these steps: 

Remove the grounding screw from the rear panel of the switch chassis. 

Put the supplied OT terminal of the PGND cable on the grounding screw. 

Fasten the grounding screw, which is attached with the OT terminal of the PGND cable, into the 
grounding screw hole with a screwdriver.