NIU3
STANDALONE
HOUSING
CLEI: NCM57WVD_ _
GENERAL
This job aid is used in association with the NIU3 circuit card job aid, P/N 61212075Lx-22.
INSTALLATION AND LOCATION
After unpacking the unit, inspect it for damage. If damage is noted, file a claim with the carrier,
then notify ADTRAN. See WARRANTY.
The standalone housing is designed to mount to a plywood backboard. The body has four
mounting screw holes on raised extrusions, which provide clearance from the backboard. The
housing interior holds a host circuit board designed to accept the NIU3 unit. Card guides direct
the NIU3 for correct insertion and also prevent vertical movement. When properly inserted,
thumbscrews on the NIU3 front panel align and fasten to threaded holes on the standalone body,
providing a secure assembly.
The rear panel has portals for power and ground wires, plus four BNC connectors:
■Two for Network Transmit/Receive
■Two for Customer Transmit/Receive
All front and rear panel items are clearly labeled. A wire-tie anchor point is also on the rear
panel.
Mounting
NOTE: Install the unit per NEC NFPA 70 requirements.
The NIU3 standalone housing can mount at any convenient location adjacent to the customer:
1. Position the housing at the designated location.
NOTE: The NIU3 can pass both network and customer signals up to 900 feet. However, if either
distance exceeds 450 feet, the respective front panel monitoring signal begins to degrade. Also,
during NIU3 bypass operations, if total transmission distance exceeds 900 feet, signal quality may
degrade. Refer to circuit diagram in Operation section on reverse.
2. Ensure the housing is plumb, then mark the four mounting holes for pilot hole location.
3. Using an appropriate sized bit, drill the four pilot holes.
4. Align the housing to the pilot holes and fasten to the backboard with the supplied screws.
5. Align the NIU3 to the card guides and insert into the housing until firmly seated into the edge
connector, then secure with the front panel thumbscrews.
Wiring
Wiring consists of two elements: power and data.
NOTE: Use suitably sized copper conductors only.
Power
During normal NIU3 operation maximum power is 125 mA @
–48 VDC. Local DC power is fed through the power portal on the rear
panel terminating at TB1, which has spade lug terminals for 48V(–),
48V(+)/GND, and Frame Ground. See NOTE in COMPLIANCE
section for requirements.
Optional power is from a standard 120 VAC grounded wall outlet via
a separately purchased AC/DC transformer (P/N 1212074L1) rated at
48 VDC @ 200 mA (125 mA minimum).
WARNING: Ensure power is off before making wiring connections.
1. From a local power source, feed the wire through the Power portal on
the housing rear panel.
2. Make wiring connections to TB1 as shown.
Ground
CAUTION: Terminate grounds to an approved ground location. Check
metal to metal contact on all ground connections, ensure ground circuit
continuity.
Standard ground is through the ground wire terminal on TB1.
An optional ground is via the ground wire portal on the rear panel
terminating at the host circuit board ground lug (J1). J1 is electrically
connected to TB1.
NOTE: J1 is a screw compression terminal requiring copper wire.
The optional AC/DC transformer ground is via the green wire terminating at the ground terminal
on TB1.
After all wiring connections are made, dress and lace wire runs to workmanship standards.
Data
Connect the cables to the four BNC connectors on the rear panel:
■Two (IN/OUT) for Customer Receive/Transmit
■Two (IN/OUT) for Network Receive/Transmit.
■If not already accomplished, connect the opposite ends to their designated connectors.
Fuse
The –48 VDC is fused on the NIU3 card.
■ For a complete Installation and Maintenance Practice (P/N 1212070L2-5): 877-457-5007, Faxback Document 9 2. Please have your fax number ready. ■
