Chapter 4 Installation in a Hazardous Environment
Verifying Switch Operation
4-22
Catalyst 2955 Hardware Installation Guide
78-14944-03
Caution The switch must be installed with 2 A-branch-circuit protection.
Caution This installation must comply with all applicable codes.
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.
To wire the switch to a DC-input power source, follow these steps:
Step 1 Locate the power and relay connector (see Figure 4-5).
Figure 4-5 Power and Relay Connector
Step 2
Identify the positive and return feed positions for the power and relay connector.
The positive DC power connection from power supply A is labeled VA, and the
return is the adjacent connection labeled RT. The positive DC power connection
from power supply B (the redundant power supply) is labeled VB, and the return
is the adjacent connection labeled RT.
Step 3 Measure two strands of twisted-pair copper wire (18 to 20 AWG) long enough to
connect to the DC power source.
Step 4 Using an 18-gauge wire-stripping tool, strip each of the two wires coming from
each DC-input power source 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.
104353
RT
A1
A2
VB
VA
A1
A2
RT
