Grass Valley NV5128 v.2.5 - Manual (Page 14)

4 Rev 2.5 • 24 Sep 09
2. Introduction
Power Supply
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 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 output; 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
LEDs and output test points located on the front of each PS6000 power supply module. Under nor-
mal operation, all five LEDs are lit. For more information, see
Indicator LEDs on page 76.
Caution If airflow is impeded, overheating can occur.