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1. GENERAL DESCRIPTION
1.1. The Westell NPGMT1125 Fuse Panel
provides up to 20 circuits for the distribution of
DC power to equipment. Each of the 20 circuits
is individually protected by a GMT style
telecommunication fuse (20A max) located on
the panel's faceplate. Alarm circuits are
provided to indicate and extend alarm
conditions when faults occur. Normal Operation
LEDs are provided to indicate the status of each
bus in the panel.
1.2. Input wiring is connected to a high current,
2-hole lug input block located at the rear of the
panel. A 90 degree standard copper barrel
compression lug is recommended for
connecting power to the input block (see page 4
for compatible lugs). Each group of fuses or
bus has its own completely isolated inputs,
allowing the distribution of two battery voltages
through the same panel.
1.3. The power is distributed to the load side
equipment through GMT style fuses. There are
10 fuses per fuse group and two groups per
panel. Each fuse position is available for
installer connection at the rear of the panel. A
designation card is provided for keeping records
of which position is connected to which
equipment and what amperage is to be used.
1.4. Alarm circuits are provided to alert service
personnel of fault conditions. A fuse alarm is a
blown fuse within a given bus. A red fuse alarm
LED
!
on the faceplate will illuminate when
a fuse alarm condition is present. As well, the
green Normal Operation LED
9
will extinguish
to signal a fuse alarm or input power failure. If a
fuse failure occurs, the alarm relay for that bus
will change state. These fuse panels have
common (C), normally open (NO) and normally
closed (NC) terminals for alarms for each bus.
Note, the use of the alarm contacts is optional, if
you do not wish to extend the alarms, you don’t
have to do anything with the alarm outputs. The
“Normal” condition of the relay exists when
there are no blown fuses in the panel.
The local
alarm LEDs are located on the front of the panel
as shown in Figure 1.4.1.
LED SYMBOL
SIGNIFICANCE
GREEN
9
NORMAL OPERATION
RED
!
BLOWN FUSE
10
7
8
9
2
1
3
POS
9
!
Ì
9
!
Ì
Figure 1.4.1
1.5. The NPGMT Fuse Panels are made from
0.050" steel and painted off-white. The
NPGMT1125 is designed to fit 19" wide racks
and use only one 1.75" panel space.
2. APPLICATION
2.1. The NPGMT1125 Fuse Panels are
designed to be used in the distribution of DC
power. They are rack mount panels that can
provide fused DC power to up to 20 individual
circuits, or 10 pieces of equipment, providing
redundant battery feeds to each.
2.2 The NPGMT family fuse panels are suitable
for installation as part of a Common Bonding
Network (CBN) for electrically bonding the shelf
type chassis of this fuse panel to its equipment
rack (via mounting brackets or chassis bonding
studs). Note that all power return inputs (RTNs)
are electrically isolated from each other and from
the fuse panel chassis. As well, this family of fuse
panels is suitable for restricted access locations in
Network Telecommunications Facilities and OSP.
3. CIRCUIT DESCRIPTION
3.1. Power is connected to the fuse panel via
¼” studs on 5/8” centers located at the rear of
the panel (torque 5.5 ft-lbs). These inputs are
high current stud blocks that supply current to
the fuse panel. Connect the battery return cable
to the stud input that is labeled “RTN” and the
Battery supply cable to the terminals labeled
“BAT”.