01-18-2014 06:38 AM - edited 03-07-2019 05:38 PM
Strange question regarding power provision. I have 4510R+E with 2 PWR-C45-6000ACV supplies with 4 identical feeds. The switch is configured for power redundancy mode. (We have many of these - all exhibit the same problem - identical hardware/IOS/config).
When one of the power feeds is disconnected, the whole PSU goes into error disable. I wasnt expecting this to be the case and we are drawing no where near any capacity.
Is this correct behaviour, bug or misconfig? Do we need to specify max psus (not that I was expecting to do so?)
Thanks
Matt
Power Fan Inline
Supply Model No Type Status Sensor Status
------ ---------------- --------- ----------- ------- -------
PS1 PWR-C45-6000ACV AC 6000W err-disable good good
PS1-1 220V good
PS1-2 off
PS2 PWR-C45-6000ACV AC 6000W good good good
PS2-1 220V good
PS2-2 220V good
*** Power Supplies of different type have been detected***
Power supplies needed by system : 1
Power supplies currently available : 1
Power Summary Maximum
(in Watts) Used Available
---------------------- ---- ---------
System Power (12V) 1200 2200
Inline Power (-50V) 497 4760
Backplane Power (3.3V) 40 40
---------------------- ---- ---------
Total 1737 (not to exceed Total Maximum Available = 6000)
Output Power To Chassis Input Power
======================================= ==================
Power Measurement System Power (12V) Inline Power (-50V)
(in Watts) (+/- 12W) (+/- 50W) (+/- 5%)
------------------ ------------------ ------------------- ------------------
PS1 171 110 412
PS2 372 250 828
------------------ ------------------ ------------------- ------------------
Total 543 360 1240
Note: System power budget is 1200 Watts to accommodate peak power utilization.
01-18-2014 07:17 AM
No completely sure, but I think this is what is happening:
When you have a 6000W power supply with 2 feeds, that is essentially 2 3000W power supplies each with one feed.
So, when you disconnect one of the 2 feeds, the system thinks, the power supplies mismatch now since one is 6000 and the other 3000 and so it puts the 3000 one in err-disable.
Also, have a look at this link for more info:
When you insert power supplies in your switch, use power supplies that are of the same wattage. Multi-input power supplies such as 1400 W DC triple-input and 4200 W AC have additional restrictions. Read the sections on special considerations for these power supplies. If you mix power supplies, the switch will use the one it recognizes first and ignore the other power supply. The power supply status displays as err-disable and the summary displays as all zeros (0) for wattage values in the output for the show power command.
HTH
01-19-2014 07:50 AM
Thanks, I've seen that link. Also found another document that states if only one input is connected to the 6000w supply, the total output power is 3000w.
So I'm wondering what happens if we disconnect 1 or 2 feeds of the primary PSU - what will happen? Unfortunately it's a live switch, but it may have to be control tested to find the answer
01-19-2014 08:04 AM
So I'm wondering what happens if we disconnect 1 or 2 feeds of the primary PSU - what will happen? Unfortunately it's a live switch, but it may have to be control tested to find the answer
That exactly what I was thinking. In theory nothing should happen since you are not drawing 3000w, but the reality is that this is a live network and you probably don't want to risk bringing down the entire switch to test the PSUs.
Be nice to have a test switch...
01-30-2014 09:14 AM
Done a controlled test on this now. By swapping to any 1 or combination of the 4 supplies the switch continues to work and adjusts accordingly without any visible problems. Didnt see any packet loss on a test I was running at the same time. (although the results would be very different if I was drawing over 3000w).
The err-disable and syslog messages are probably a bit misleading. Only when the 1 + 1 or 2 + 2 inputs are in and working does it remove the err-disable on the supply.
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