Hi Satheesh,
In the "show power" output do you see the part info as External Power supply?
show power
PowerSupply 1 information:
State: Powered Off
PartInfo: Internal Power Supply
Input: 0.00 V AC
PowerSupply 2 information:
State: Powered On
PartInfo: External Power Supply
Input: 0.00 V AC
PowerSupply 3 information:
State: Powered On
PartInfo: External Power Supply
Input: 0.00 V AC
PowerSupply 4 information:
State: Powered On
PartInfo: External Power Supply
Input: 0.00 V AC