Cisco Catalyst 2955 Series, Руководство по установке оборудования

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4-33
Catalyst 2955 Hardware Installation Guide
78-14944-03
Chapter 4 Installation in a Hazardous Environment
Wiring the External Alarm Device Relays
Warning The switch relays are rated at 1 Amp and have a voltage limit of 30 VDC and 0.3
Amp at a voltage limit of 125 VAC. It is dangerous to exceed these limitations in
a hazardous environment.
An electrical arc can occur when you connect or disconnect the relay wires
with field side power applied. This could cause an explosion in switch
installations in a hazardous location. Before proceeding, be sure that power is
removed or the area is not hazardous.
Statement 1061 .
Note
For wire connections to the power and relay connector, you must use UL and CSA
rated, style 1007 or 1569 twisted-pair copper appliance wiring material (AWM)
wire (such as Belden part number 9318).
You must also use the ferrite that ships with the switch.
After you have completed the wiring for the DC power connections, follow these
steps to wire the switch to an external alarm device:
Note
This procedure is optional.
Step 1
Measure one strand of twisted-pair wire (18 to 20 AWG) long enough to connect
to the external alarm device.
Step 2
Use a wire stripper to remove the casing from both ends of the wire to 0.25 inch
(6.3 mm) ± 0.02 inch (0.5 mm). Do not strip more than 0.27 inch (6.8 mm) of
insulation from the wire. Stripping more than the recommended amount of wire
can leave exposed wire from the power and relay connector after installation.
Step 3
Insert the exposed wires for the external alarm device into the two connections
labeled A1, as shown in
Figure 4-13 .