Transition Networks SM24-1000SFP-AH, Installation Manual

Page: 39 / 76

3-7
Grounding the Chassis
3
Grounding the Chassis
Before powering on the switch, ground the switch to earth as described below.
1. Ensure that the rack on which the switch is to be mounted is properly grounded
and in compliance with ETSI ETS 300 253.
2. Ensure that there is a good electrical connection to the grounding point on the
rack (no paint or isolating surface treatment).
3. Disconnect all power cables to the switch.
4. The switch chassis is connected internally to 0 V. This circuit is
connected to the single-hole grounding terminal on the front of the
switch (lower left corner). The surface area around this terminal is not
painted in order to provide for a good connection. Attach a 6 AWG stranded
copper wire to the grounding terminal on the switch.
5. Then attach the grounding wire to the ground point on the rack.
Caution:
The earth connection must not be removed unless all supply connections
have been disconnected.
Connecting to a Power Source
This switch supports both AC and DC power conversion modules.
Connecting DC Power
When a -48 VDC VDC power conversion module is installed in the switch, an
external DC power supply must be connected to the DC power connection on the left
side of the front panel.
Warning: Before wiring the DC plug or connecting power to the switch, ensure that
power to the feed lines is turned off at the supply circuit breaker or
disconnected from the power bus.
Notes: 1. To provide adequate circuit protection between the DC power supply and the
switch, all intermediate wiring and circuitry should be rated to carry a load at
least two times the maximum rating for this switch.
2. The wiring between the DC power supply and the switch must be stranded
copper wire within the range of 10 to 24 AWG.
3. Wiring for the power input terminals on the switch are described below.
Wiring of the DC power supply terminals depends on the equipment in use
on the local site, but should be wired in such a way as to meet the input
requirements shown in Figure 3-7 “DC Plug Connections” on page 3-8. The
wiring should also be color coded according to local standards to ensure that
the input power and ground lines can be easily distinguished.