Output Power Redundancy And Load Sharing - Cisco VCO/4K Mechanical Assemblies

4.1 Output Power Redundancy and Load Sharing

The main power supply module is on the left of all VCO/4K systems. In nonredundant systems,
ensure that the power supply module is on the left.
The following describes the power supply load-sharing and redundancy in VCO/4K systems:
• The modules share the total load on each voltage in redundant systems.
• The system automatically remains in operation without interruption, during and after
a power supply module failure. The system disconnects the failed module and switches
all power to the redundant module.
• The power supply modules provide individual load-sharing for each voltage. If a voltage
failure occurs, it continues to load-share the remaining voltages.
For example, if the +5VDC voltage fails in a power supply module, the remaining volt-
ages are not affected, and continue to load-share with the other module.
• Each module is equipped with a 25-amp fuse, ensuring that redundancy is maintained
in the event of an overcurrent fault. If a fuse blows in one power supply module, the
system does not shut down.
The power supply module provides six regulated DC voltages for system operation, as shown
in Table 3.
Table 3: Power Supply Module Output Voltages
Voltage Tolerance
±0.25V
+5VDC
±0.5V
+15VDC
±0.5V
–15VDC
+3V, -0V
+12VDC
±1.0V
+24VDC
±4.0V
–48VDC
Input and output Power Distribution
Current
84 amps
4 amps
4 amps
1 amp
1 amp
3 amps
VCO/4K Power Subsystem 1-11