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Cisco MGX 8230 Edge Concentrator Installation and Configuration
Release 1.1.31, Part Number 78-11215-03 Rev. B0, May 2001
Chapter 3 Site Preparation
Power and Grounding
Figure 3-3
Mixed Grounding System
Table 3-1
Ground Point Descriptions for Mixed Grounding
Connection
Description
Z1
–48 VDC return.
Z2
Protective earth or safety ground (green/yellow).
Z3
Equipment ground for non isolated equipment.
Z4
Equipment ground for isolated equipment.
Z5
Equalizing frame ground. This ground creates low-impedance equalization
between frames.
B
Battery ground.
1, 2, 3, 4
Connection points to the building’s ground system: a potential can exist between
these points within the ground system.
T
Common-mode EMI filters.
Battery A
Non-isolated equipment
– 48V-A
T
– 48V-A
– 48V-A
logic power
+
–
– 48V-B
1
1
B
2
B
T
T
Safety Ground
Safety Ground
Safety Ground
– 48V-A RTN
– 48V-A
– 48V-A RTN
– 48V-B
– 48V-B RTN
– 48V-B
– 48V-B RTN
Safety Ground
Battery B
– 48V-B
+
–
Isolated equipment
– 48V-A
logic power
– 48V-B
2
4
T
Z1
Z1
Z1
Z1
Z2
Z2
Z2
Z2
Z3
3
Z4
Z5
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