Figure 3. Niu3 12-Slot Shelf Rear Panel; Figure 4. Local Dc Power Connection - ADTRAN NIU3 Installation And Maintenance Practice

COM NC NO
NOTE: Power and Alarm security covers removed for clarity.
Power
Fully populated, the NIU3 shelf operates on local –48
VDC @ 1.5 amps maximum. The shelf backplane has
spade lug terminal connections (TB1) for both an
"A-side" and "B-side" independent DC source, plus
Frame Ground (see Figure 4). A diode arrangement
adds reliability by allowing both DC supplies to
load-share with one side picking up the entire load
should the other side fail. See requirements in
Compliance subsection.
A SUPPLY
A RETURN
B SUPPLY
B RETURN
FRAME
GROUND

Figure 4. Local DC Power Connection

61212078L2-5A

Figure 3. NIU3 12-Slot Shelf Rear Panel

TB1
-48V A
-48V RET A
-48V B
-48V RET B
Section 61212078L2-5, Issue 1
48V , 1.5A
USE COPPER CONDUCTORS ONL Y
THIS UNIT MA Y BE POWERED BY MULTIPLE SOURCES.
DISCONNECT ALL SOURCES PRIOR TO SERVIGING.
WARNING
Ensure power is off before making power
wiring connections.
• Connect the –48 VDC supply and return wires
to the A-side terminals per Figure 4.
• If redundant power is intended, connect
an independent power source to the B-side
terminals per Figure 4.
CAUTION
Terminate grounds to an approved ground
location. Check metal to metal contact on all
ground connections, ensure ground circuit
continuity.
• Connect the common frame ground terminal
to an approved ground location.
CAUTION
Per GR-1089-CORE, October 2002, Section 9,
this system is designed and intended for
installation in a DC-C (common) bonding and
grounding system only. It is not intended or
designed for installation in a DC-I (isolated)
bonding and grounding system.
DC POWER
Ð48 V Ð48 V Ð48 V Ð48 V
RET B B RET A A
3