Figure 3-9 Creepage And Clearance Distances Between Bri Module And Components - Cisco EF4116 Hardware Installation And Maintenance Manual

Making Network Connections
Maintaining Safe Installation Distances
Except at the edge connector that plugs into the host chassis expansion slot, clearance and creepage
distances of X millimeters (mm) and Y mm as listed in Table 3-3 must be maintained between the
cards and other parts of the host, including any other expansion cards fitted.
Note that in Table 3-3:
•
•
Table 3-3
Voltage Used or Generated by Other Parts
of the Host or Expansion Card (Vrms or VDC)
Up to 50
Up to 125
Up to 250
Up to 300
1. Vrms = root mean square voltage.
2. The creepage distances not in parentheses apply when the equipment is installed in a normal office environment. The larger
dimensions, in parentheses, must be applied when the equipment is installed in an environment in which dust and other types
of pollution could conduct electricity because of the effects of dampness and condensation. This applies to locations subject
to high humidity.
Creepage and clearance distances are measured between adjacent parts as shown in Figure 3-9.
Figure 3-9
Note that in Figure 3-9, X indicates the clearance distances between cards and adjacent cards and
components, and Y shows the creepage path across the surface of an insulator and between the two
points indicated by X.
3-10 Cisco 4000 Series Hardware Installation and Maintenance
Clearance distances are defined as the minimum distance measured in air between two points
(i.e., line of sight).
Creepage distances are defined as the minimum distance measured across the surface of an
insulator, between two points (i.e., following the contour of the insulator).
Creepage and Clearance Distances Based on Voltage
Creepage and Clearance Distances between BRI Module and Components
Host
y
x
Component
1
Card Adjacent card
x
2
Creepage (Y mm) Clearance (X mm)
2.4 (3.8) 2.0
3.0 (4.8) 2.6
5.0 (8.0) 4.0
6.4 (10.0) 4.0