Grass Valley NV8500 Series v.3.5 - Manual (Page 22)

6
Introduction
Overview of the Routers
Overview of the Routers
NV8500 series routers share common frame features. All I/O cards, crosspoint cards, monitor
cards, and control cards are installed through the frame front. All system connections and back-
plane modules are located at the rear of the frame.
The following is an overview of each router. For more information about any modules
mentioned, see the related topic:
• Inputs and Outputs on page 21
• Crosspoints on page 63
• Monitoring on page 89
• Router Control on page 83
• Power on page 119
Frame Cooling
The routers have one or more fan trays providing forced air cooling through five speed-
controlled fans. The fans draw air from the center and front of the router, through its door, and
exhaust it through the rear of the frame.
Each fan features speed control which spins the fan at the optimal rate required to ensure that a
constant temperature is maintained within the router frame. Temperature sensors at the inlet of
each fan increase or decrease the speed of the fan as required. Because the fans rotate only as
needed, fan noise is significantly reduced in partially loaded frames or in environments with
lower ambient temperatures. Maintaining a constant temperature ensures the proper operation
of router circuitry.
In the NV8144, NV8140, and the NV8280 frames, a single fan tray is located at the top of the
chassis. For the NV8576 (and NV8576-Plus) frames, there are two fan trays: one located at the top
and one located at the bottom of the frame. Each fan features two LEDs that indicate whether
the fan is receiving power and whether there is a failure. For more information, see
Indicator
LEDs on page 193.
There is a removable air filter located on the inside of the door assembly. It is recommended that
filter maintenance be performed on a regular basis. For more information, see
Air Flow on
page 197.
Fuses
The NV8500 series routers have no user-serviceable fuses.