configuring nmc

[Anonymous user]

I´m a bit confused about the the configuration of the NMC
I have a SMART 3000 UPS with a NMC. The load is 50%. After 5 min the following message appears:
"The battery power is too low to continue to support the load; the UPS will shut down if input power does not return to normal"
At the same time it shows a remaining time of 5min.Where does thse 5 min come from and does it mean that a really have 5 min left?

Am I right that this is the configurable "Low Battery Duration" time?
What does the "shutdown delay" mean and what is the difference to the "Low Battery Duration"?

It would be nice if someone have some answers to my questions.


cheers
frank

[voidstar_apc]

Hi fherfs, good questions!

After a power failure occurs, the UPS goes on battery. When the runtime remaining drops below the low runtime threshold, the NMC sends out notification that the battery is low and initiates a safe shutdown. If you have computers running PowerChute Network Shutdown attached to the NMC, they will start turning off your computers (PCNS can also be configured to do so in other conditions). The NMC waits for the Shutdown Delay period after starting the shutdown before turning off the UPS.

One question you might ask is why have a shutdown delay at all? Why not keep the UPS on as long as possible which in your case is at least 5 minutes? Part of the reason for this is once computers are turned off, the UPS is required to turn off and back on to turn those computers back on. So even if the power comes back after the shutdown starts, the UPS still has to turn off. As long as the UPS has to turn off, it might as well do it at the earliest opportunity. That way there is still energy left in the battery to perform a safe shutdown if the power comes back briefly but fails again.

[Anonymous user]

Thanks for answering so fast.
It was exactly the answer I was looking for


cheers
frank

[Techie_apc]

Frank,

Let me also inform you about the "UPS:On battery" event configuration which can be found in the PCNS software.

I have found the below useful information somewhere on the discussion forum threads.

+In PCNS, the configure events page can be configured to shutdown or run a command file based on several different types of events. (for example, if you wanted this particular server to shutdown after the UPS had run on battery after 1 minute to preserve battery power, you could do that on the configure events page.) by default, it will always shutdown though based on the low battery duration that you have set in the network management card. For configuration settings based on the low battery duration, this should be configured under Server name->Configure shutdown which states: When Power Chute shuts down your operating system, it will use these settings. Use the Configure Events page to select which events will cause the system to shut down.+

So, if you have the low battery duration set to 10 minutes in the management card, the runtime should hit 10 minutes, and then your server with PCNS will receive this notification from the management card. Then it will run the command file and after 3 minutes, proceed to do a graceful shutdown.

If you want to shut something down at a different point other than the low battery duration, i would suggest configuring UPS: On battery event. So you could configure the UPS to shutdown (or even run a command file, notify a user) to happen after the UPS has been on battery for x amount of seconds.

Message was edited by: Techie

[Techie_apc · Accepted solution]

Glad to hear that you got an answer. Have a nice weekend!