Hello everyone,
I have a WS-C6509-E with two WS-CAC-6000W power supplies. I have to determine what is the real power consumption of the whole device but I noticed that there is a mismatch between measurements and show power output so I would very much appreciate if someone could explain why is that so.
I did the following test to try figure out the consumption from the power grid.
Step 1. When both supplies are active, show power gives me the following output:
C6509Test#show power
system power redundancy mode = redundant
system power total = 5771.64 Watts (137.42 Amps @ 42V)
system power used = 2253.72 Watts (53.66 Amps @ 42V)
system power available = 3517.92 Watts (83.76 Amps @ 42V)
Power-Capacity PS-Fan Output Oper
PS Type Watts A @42V Status Status State
---- ------------------ ------- ------ ------ ------ -----
1 WS-CAC-6000W 5771.64 137.42 OK OK on
2 WS-CAC-6000W 5771.64 137.42 OK OK on
Pwr-Allocated Oper
Fan Type Watts A @42V State
---- ------------------ ------- ------ -----
1 WS-C6509-E-FAN 150.36 3.58 OK
Pwr-Requested Pwr-Allocated Admin Oper
Slot Card-Type Watts A @42V Watts A @42V State State
---- ------------------ ------- ------ ------- ------ ----- -----
1 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
2 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
3 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
4 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
5 VS-S720-10G 338.10 8.05 338.10 8.05 on on
6 VS-S720-10G 338.10 8.05 338.10 8.05 on on
7 WS-X6724-SFP 125.16 2.98 125.16 2.98 on on
system auxiliary power mode = off
system auxiliary power redundancy operationally = non-redundant
system primary connector power limit = 10920.00 Watts (260.00 Amps @ 42V)
system auxiliary connector power limit = 10500.00 Watts (250.00 Amps @ 42V)
system primary power used = 2253.72 Watts (53.66 Amps @ 42V)
system auxiliary power used = 0 Watt
Step 2. Then I switched off power supply 1:
C6509Test#
*Jan 22 09:29:21.753: %C6KPWR-SP-4-PSOUTPUTDROP: Power supply 1 output has dropp
ed
*Jan 22 09:29:21.769: %C6KPWR-SP-2-PSFAIL: power supply 1 output failed.
*Jan 22 09:29:21.769: %C6KPWR-SP-4-PSREDUNDANTONESUPPLY: in power-redundancy mod
e, system is operating on one power supply.
C6509Test#
C6509Test#show power
system power redundancy mode = redundant
system power redundancy operationally = non-redundant
system power total = 5771.64 Watts (137.42 Amps @ 42V)
system power used = 2253.72 Watts (53.66 Amps @ 42V)
system power available = 3517.92 Watts (83.76 Amps @ 42V)
Power-Capacity PS-Fan Output Oper
PS Type Watts A @42V Status Status State
---- ------------------ ------- ------ ------ ------ -----
1 WS-CAC-6000W 3780.00 90.00 - - off
2 WS-CAC-6000W 5771.64 137.42 OK OK on
Pwr-Allocated Oper
Fan Type Watts A @42V State
---- ------------------ ------- ------ -----
1 WS-C6509-E-FAN 150.36 3.58 OK
Pwr-Requested Pwr-Allocated Admin Oper
Slot Card-Type Watts A @42V Watts A @42V State State
---- ------------------ ------- ------ ------- ------ ----- -----
1 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
2 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
3 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
4 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
5 VS-S720-10G 338.10 8.05 338.10 8.05 on on
6 VS-S720-10G 338.10 8.05 338.10 8.05 on on
7 WS-X6724-SFP 125.16 2.98 125.16 2.98 on on
system auxiliary power mode = off
system auxiliary power redundancy operationally = non-redundant
system primary connector power limit = 10920.00 Watts (260.00 Amps @ 42V)
system auxiliary connector power limit = 10500.00 Watts (250.00 Amps @ 42V)
system primary power used = 2253.72 Watts (53.66 Amps @ 42V)
system auxiliary power used = 0 Watt
Step 3. Now I disconnect the power input 1 on running power supply 2 thus leaving the device working on only one out of four power inputs:
C6509Test#
*Jan 22 09:35:50.297: %C6KPWR-SP-4-INPUTCHANGE: Power supply 2 input has changed
. Power capacity adjusted to 2671.20W
*Jan 22 09:35:50.297: %C6KPWR-SP-4-PSOUTPUTDROP: Power supply 2 output has dropp
ed
C6509Test#show power
system power redundancy mode = redundant
system power redundancy operationally = non-redundant
system power total = 2671.20 Watts (63.60 Amps @ 42V)
system power used = 2253.72 Watts (53.66 Amps @ 42V)
system power available = 417.48 Watts ( 9.94 Amps @ 42V)
Power-Capacity PS-Fan Output Oper
PS Type Watts A @42V Status Status State
---- ------------------ ------- ------ ------ ------ -----
1 WS-CAC-6000W 3780.00 90.00 - - off
2 WS-CAC-6000W 2671.20 63.60 OK OK on
Pwr-Allocated Oper
Fan Type Watts A @42V State
---- ------------------ ------- ------ -----
1 WS-C6509-E-FAN 150.36 3.58 OK
Pwr-Requested Pwr-Allocated Admin Oper
Slot Card-Type Watts A @42V Watts A @42V State State
---- ------------------ ------- ------ ------- ------ ----- -----
1 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
2 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
3 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
4 WS-X6748-GE-TX 325.50 7.75 325.50 7.75 on on
5 VS-S720-10G 338.10 8.05 338.10 8.05 on on
6 VS-S720-10G 338.10 8.05 338.10 8.05 on on
7 WS-X6724-SFP 125.16 2.98 125.16 2.98 on on
system auxiliary power mode = off
system auxiliary power redundancy operationally = non-redundant
system primary connector power limit = 10920.00 Watts (260.00 Amps @ 42V)
system auxiliary connector power limit = 10500.00 Watts (250.00 Amps @ 42V)
system primary power used = 2253.72 Watts (53.66 Amps @ 42V)
system auxiliary power used = 0 Watt
C6509Test#
*Jan 22 09:37:22.317: %C6KPWR-SP-4-INPUTCHANGE: Power supply 2 input has changed
. Power capacity adjusted to 5771.64W
*Jan 22 09:38:58.523: %C6KPWR-SP-4-PSOK: power supply 1 turned on.
*Jan 22 09:38:58.535: %C6KPWR-SP-4-PSREDUNDANTBOTHSUPPLY: in power-redundancy mo
de, system is operating on both power supplies.
C6509Test#
Step 4. I used the current clamp to measure the current on the remaining power input and it reads 4.9 A.
When I multiply the current with voltage I get
P=4.9*230=1127 W.
So why does the show power output gives system power used = 2253.72 Watts, which is actually double value of measured 1127 W? What am I missing?
Thank you in advance for any help on this,
Marin
