4 Rev 2.3 • 14 Oct 08
2. Introduction
Power Supply
Mounting
The NV5128 is designed to mount in a standard EIA rack with minimum dimensions of 8RUs
(13.97 inches, 354.8
mm) high, 19 inches (482.6 mm) wide, and approximately 18 inches (457 mm)
deep. Because of the router’s compact size, multiple routers can be mounted in a single rack, saving
facility space. For installation instructions, see Rack Mount
on page 37.
Fuses
Active cards feature a “fast blow” or resettable fuse. If the card requires a large amount of power,
the fuse is “fast blow” and must be replaced if blown. If the fuses are resettable, the fuses either
reset automatically or can be reset manually by removing the card from the frame. For more infor-
mation on fuses, see Fuse Replacement
on page 76.
Cooling
The NV5128 frame has a single fan tray containing three fans with variable fan speed control. The
fans draw cooling air from the front of the router, through the door, and exhaust it through the rear
of the frame. The router must have the door installed and closed for proper airflow through the
chassis.
Each fan features speed control which spins the fan at the optimal rate required to ensure that a con-
stant temperature is maintained within the router. Temperature sensors on the fans sense the exiting
temperature and speed up or slow down the spinning of the fan as required. By spinning only as
needed to meet cooling needs, fan noise is significantly reduced in partially loaded frames or in
environments with lower ambient temperatures. In addition, by maintaining a constant temperature,
circuitry life span is increased.
Each fan features two LEDs that indicate if the fan is receiving power and if there is a failure. For
more information, see Indicator LEDs
on page 76.
Filters
There is a removable air filter located on the inside of the door assembly. It is recommended that
maintenance of the fan tray and filters be performed on a regular basis. For more information, see
Air Flow
on page 78.
Power Supply
The NV5128 uses the NVISION PS6000 power supply module, housing one primary module and
one optional module (for redundancy). The PS6000 power supply module accepts a wide range of
AC input voltages and produces five +48
VDC outputs. The power supply automatically senses the
AC input voltage (90–130 and 180–250
VAC) and adjusts to maintain a relatively constant DC out-
put; no voltage selection is required.
The five regulated outputs are directed to modules in the router where on-board regulators produce
the DC voltages required by the local circuits. Each +48
VDC output powers one of the five green
Caution If airflow is impeded, overheating can occur.
To Next Page
Loading...
General