2-8
October, 1998
GRF 400/1600 Getting Started - 1.4 Update 2
Getting Acquainted with the GRF 1600
Overview of the GRF 1600 base unit
Media cards
Note:
To operate properly, a GRF 1600 requires a minimum of two media cards installed.
Also, a face plate cover must be installed in any unused slot to maintain cooling flows.
The GRF 1600 has 16 media card slots, 0–15, a control board, and a switch board.Slots are
numbered left to right as shown in Figure 2-4, the control board is always 66:
Figure 2-4. Top view of GRF 1600 chassis with slots numbered
Chassis fans
Two motorized impeller fans cool the chassis, excluding the power supply compartment. The
fans operate in tandem. At start-up, both fans operate at 100% of RPM capability. Gradually
each fan slows down so that, in normal conditions, each fan operates at 50% speed. When the
GRF is plugged in, you can hear the changes in fan speeds. Tachometers on each fan unit
ensure steady, sufficient airflow. When a tachometer detects that a fan is dropping below the
50% rate, it causes a signal to the other fan to speed up. When a problem occurs with either fan,
the control board “FAN” LED lights. You can replace the fan tray on site, contact Lucent to
order a replacement.
The amount of time the GRF 1600 can operate with a failed fan depends upon the number of
installed media cards and the ambient air temperature. The temperature sensor on the control
board shuts the GRF down if the operating temperature is exceeded.
A procedure to exchange the fan trays is in the “Management Tasks” chapter of the GRF
Configuration and Management manual.
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
Backplane
66
Control board
Media cards:
Slot numbers:
Switch board
