Specifications

Reference Guide
3-9
System Installation Power Supplies and Ringing Generators
3.4.6 AC Power Supply and DC Supply Fuses
The AC power supply and DC Power Supply fuses are already built in to the supplies. When
unpacking the unit a power cord will be in the box. The AC inlet connector is located in the
front or rear of the chassis. Refer to the system specification section in this manual.
3.4.7 Installing AC or DC Power Supplies
To install the AC or DC power supply in a chassis, first remove the panel covering the front
power slot. Then, hold the power supply by its metal handle and align the printed circuit board
(PCB) edges with the rail guides of either power supply slot. Push the unit in until it is firmly
seated in the backplane connector, and replace the panel cover. For redundant power supplies,
also insert a second AC or DC power supply into the adjacent slot.
When the AC or DC power supply is installed and power is applied, the green LED on the
front panel of the power supply should light. A problem exists if this LED does not light.
Verify that the power supply is properly seated in the connector. Also check the external power
source and connections to the power supply. If the power supply is properly seated, and the
external power source and power connections are operational, replace the power supply.
Replace the panel cover.
3.4.8 Installing the -48V Converters (8903/8905/8908)
To install a -48V Converter in a chassis, proceed as follows. Refer to the system specification
section in this manual for the -48V Converters. Figure 3-6 shows the location of the fuse on
the converter board.
4. For a two-sided chassis, remove the panel covering the rear power slots. You may insert
or remove the module in any of the five rear slots while power is on or off. For a
front-loading chassis, remove the panel covering the front power slots. You may insert or
remove the panel while power is on or off.
5. Hold the converter by its metal handle and align the PCB edges with the slot rail guides
in the chassis. Gently push the converter in until it is firmly seated in the backplane
connector.
6. When the power converter is installed and power is applied, the green LED on the front
panel of the converter should light. A problem exists if this LED does not light. Verify that
the power converter is properly seated in the connector. If so, also check the external
power source and connection to the power supply. If the power converter is properly
seated, and the external power source and power connections are operational, replace the
converter.
7. Replace the panel cover.