2
Issue 4, August 2004
61212073L1-5D
The DS3 NIU3 3-Slot Shelf meets the following
standards:
• NEBS: Level 3
• ANSI:
T1.404
• UL:
60950
• FCC:
Part 15, Class A
3. INSTALLATION
After unpacking the unit, inspect it for damage or
missing components. If damage or missing components
are noted, file a claim with the carrier, then notify
ADTRAN. Refer to
Install per requirements of NEC NFPA 70. After
installation, ensure equipment rack stability is not upset.
Location
The NIU3 3-Slot Shelf installs at any location conve-
nient to the customer as a demarcation and loopback
point for DS3 circuits. The NIU3 can pass both network
and customer signals up to 900 feet. During NIU3
bypass operations, if total transmission distance
exceeds 900 feet, signal quality may degrade. See
for maximum recommended transmission
distances.
Rackmount
NOTE
I n s t a l l t h e u n i t p e r N E C N F P A 7 0
requirements. See
Compliance
section.
The NIU3 3-Slot Chassis can be rack mounted at any
convenient location. Reversible mounting flanges
adjust to desired position in the 19-inch rack. Also
included are 23-inch flanges. To mount the NIU3 3-Slot
Chassis in a rack, perform the following steps:
1. Determine desired shelf extension from the rack
frame.
2. Position the mounting flanges as necessary using
the appropriate flanges for a 19-inch or 23-inch
rack. Install using the supplied counter-sink
screws.
3. Mount the shelf to the rack accordingly.
Wallmount
Additional brackets available from ADTRAN allow the
chassis to be mounted to a wall. Wallmount bracket
P/N 1212073L1WM accommodates one 3-Slot Shelf.
Wallmount bracket P/N 1212078L1WM accommo-
dates a stack of two 3-Slot Chassis. Six ¼ x ¾ inch
bladed hex-head screws and flat washers are provided
with the 1212078L1WM wallmount bracket for
attaching to the wall. In this configuration, the original
flanges are removed, and the wallmount flanges are
installed using the countersink screws from the
originals. If using P/N 1212073L1WM, install the
chassis so the circuit cards’ front panels face
up
.
If using P/N 1212078L1WM, install the chassis so the
circuit cards’ front panels face
out
. A 2-foot 16 AWG
ground wire is also provided to be installed between the
ground termination on the bracket and the ground termi-
nation on the housing. This allows the chassis to rotate
without disturbing the main ground wire leaving the
bracket.
CAUTION
W h e n r o t a t i n g t h e c h a s s i s i n t h e
1212078L1WM brackets, always do so with
care to ensure that all wiring and connections
are protected.
CAUTION
There are six removable bypass relays and 1
removable alarm relay located on the rear of
the shelf. After installation, remove the relay
covers and ensure that the relays are properly
and firmly seated in their sockets. Replace the
relay covers.
4. WIRING
Wiring consists of three elements: data, power/ground,
and alarms. Use suitably sized copper conductors only.
Data
Externally, the shelf backplane has four BNC
connectors for each of the three NIU3 slots labeled
NTWK IN
/
OUT
and
CUST IN
/
OUT
(see
Wiring Connections
Connect data wiring per the following procedure:
1. Connect the cables to the BNCs on the backplane
for those shelf slots that will be populated.
2. If not already done, connect the opposite ends to
their designated terminations.
3. Dress and lace the wire runs to the bay frames as
necessary.
C A U T I O N !
SUBJECT TO ELECTROSTATIC DAMAGE
OR DECREASE IN RELIABILITY.
HANDLING PRECAUTIONS REQUIRED.
