Nokia 7210 - 3.2.5.2 Connecting to a DC Power Source

Installing the Chassis
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7210 SAS-D CHASSIS INSTALLATION GUIDE
3HE 10087 AAAA TQZZA Edition 01 Issue: 08
Step 6. Check the power LED as the switch is powered on to verify that the LED
indicating external power status is ON, and that the LED indicating internal
power conversion is ON. If not, recheck the power source and power cable
connections at the power source and at the power supply.
3.2.5.2 Connecting to a DC Power Source
3.2.5.2.1 Connecting to a –48 VDC Power Source
To connect the switch to a –48 VDC power source:
Step 1. Before a –48 VDC power supply module can be used, you must connect an
external DC power source to the DC power connection on the right side of
the front panel. The DC power source must be between –36 to –72 VDC,
and protected with a circuit breaker.
To provide adequate circuit protection between the DC power source 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 (see section 7).
Step 2. The wiring between the DC power supply and the switch must be stranded
copper wire within the range of 10 to 24 AWG.
Warning:
• Confirm that the DC power source is OFF during installation. Locate the circuit breaker
on the panel board that services the DC circuit and switch the circuit to the OFF position.
For extra safety, you can tape the handle of the circuit breaker in the OFF position.
• Turn OFF power at the power source before you install or remove power cables or
cords.
• When wiring the unit, the chassis ground connection must always be made first and
disconnected last.
• Although the system provides four input pins to connect a DC power source, use the
top two pins only. Pins 3 and 4 are not connected or recommended.
Note: An additional chassis ground point is located below the DC power entry block, for
attaching a DC power chassis ground if required by local electrical codes. The ground point
should be connected with an M4 screw and a terminal lug as specified by local electrical
codes.