Quick Start Guide
Flatpack2 PS System, 4U, SP2-based
356825.103, 2v0 -2011-09
17
About AC, DC Earthing Systems
To prevent the risk of electric shock, all cabinet’s chassis are to be electrically
connected to AC Earth (PE). Also, it is a common practice for telecom equipment
to have its common DC output rail (+ or –) connected to a separate “Telecom
Earth” (TE) or DC Earth.
Earth connections are in particular important where frequent lightning might
induce high voltage levels in AC supply and in battery and load cables.
At factory, AC Earth (PE) and DC Earth
(TE) are connected to chassis. Remove
“Link EG” (“floating earth”) for compliance
with other local earthing systems.
Refer to your system’s
specific drawings
to
identify how earth connections are
implemented in your DC power system.
“Common Positive DC Output Rail” is usual in 48 and 60V DC supply systems:
Negative DC
Distribution
. “Common Negative DC Output Rail” is usual in 24V systems:
Positive DC
Distribution
.
AC Mains
Appendix
Cabinet
PE
AC Mains
Common
DC Rail
EG
.
A
C Mains Input
(L1,L2,L3,
N)
DC Load
Circuit
Link “EG”
(DC Earth)
(AC Earth)
TE
Chassis
Chassis
PE (Protective Earth)
TE (Telecom Earth)
EG (Exchange Ground)
Common DC Rail —
DC Load
wires
+
+
+
+
Positive DC
Distribution
—
—
—
—
Negative DC
Distribution
Common DC Rail +
DC Load
wires