61212070L2-5A
Section 61212070L2-5, Issue 1
3
Mounting
Install the unit per NEC NFPA 70 requirements. The
NIU3 standalone housing can mount at any
convenient location adjacent to the customer:
• Position the housing at the designated location.
• Ensuring the housing is plumb, mark the four
mounting holes for pilot hole location.
• Using an appropriate sized bit, drill the four pilot
holes.
• Align the housing to the pilot holes and fasten to
the backboard with supplied screws.
Connections
The NIU3 operates on local –48 VDC. The
standalone housing has a power wire portal on the rear
panel for termination at TB1, which has spade lug
terminals for 48 V(–), 48 V(+)/GND, and Frame
Ground (see
Figure 4
).
Optional frame ground is provided by a ground lug
(J1) on the host circuit board. J1 is electrically
connected to TB1. A ground wire portal on the rear
panel of the housing provides access for this ground
wire. J1 is a screw compression terminal requiring a
solid copper wire.
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.
Wiring
Wiring consists of two elements: power and data. The
host circuit board power terminal strip (TB1) is
designed for spade lug terminations. Use suitably
sized copper conductors only.
Power
WARNING
Ensure power is off before making wiring
connections.
• From a local power source, feed the wire through
the Power portal on the housing rear panel.
• Make wiring connections to TB1 as shown in
Figure 4 or 5 as applicable.
• Dress and lace wire runs as necessary.
Figure 4. Local DC Power Connection
Figure 5. AC/DC Transformer Power
An optional power source is from a standard 120 VAC
wall outlet via a separately purchased transformer
with 48 VDC @ 200 mA output. In this case the (red)
power wire is connected to the 48 V(+)/GND terminal
and the (black) return wire to the 48 V(–) terminal.
The green wire connects to the Frame Ground
terminal (
Figure 5
). See requirements in
Compliance
subsection.
CAUTION
Terminate grounds to an approved ground
location. Check metal to metal contact on all
ground connections, ensure ground circuit
continuity.
48V(+)/GND
GRN
RED
BLK
TB1
48V
200mA
48V(–)
RETURN
SUPPLY
48V( + )/GND
TB1
48V( - )
J1
