Posted: 2021-06-30 09:59 PM
This question was originally posted by Joseph on APC forums on 9/4/2016
I've tried to sort out the run time options as seen via the 9617 cards on my various Smart UPS's. They are protecting radio equipment, not computers. So the goal is maximum run time, without needing any warnings to the attached equipment. They then need to come back on ASAP, regardless of the batteries being recharged at all.
What I'm still not quite able to sort out is the impact of the shut down delay and the low battery duration settings on the UPS behavior in a strictly stand-alone setup, meaning the only thing of interest here are the batteries running out.
Here's my take on these from my confused reading. Please tell me if I've got anything wrong with them.
shut down delay - This timer starts when a sleep or reboot command is initiated manually from the web interface, SNMP, external software like PowerChute, other servers, or internally from a scheduled shutdown. At the end of the delay, the UPS shuts off. (Using the "turn off UPS" command does not use this delay and is immediate.) But when on backup power, the battery voltage hits the "too low" trigger point and the UPS is ready to shut off, the delay serves no role here. In other words does this delay have anything to do with total run time?
low battery duration - This is not a timer, but rather a value the UPS uses as a trigger point to signal external devices that the end is near. e.g. If the value is set to "5" the UPS signals equipment that it has calculated 5 minutes left of battery life, then shutdown will occur. Low battery duration has nothing to do with run time; it is for signalling other gear.
sleep time - The timer starts when the UPS is put to sleep after a manual or scheduled sleep command is initiated via the web interface or external software. At end of sleep time, the UPS turns on and restores output power. Sleep time does not apply to an exhausted UPS restarting after source power returns.
minimum battery capacity - When source power returns after a prolonged outage exhausts the UPS, this parameter sets a requirement for the batteries to be recharged above a certain % level before UPS will turn output power back on. In my case, I set to "00" to restore output power immediately.
return delay - When source power returns, this wait timer starts, and turns the output power on when it concludes. This timer is only used when power returns to an exhausted UPS as part of the restart sequence.
Any comments on this would be appreciated!
Posted: 2021-06-30 09:59 PM
This was originally posted on APC forums on 9/5/2016
You got it.
Your SmartUPS will continue operating until the battery is exhausted unless told to shutdown earlier. While the newer AP9630/31/35 cards have some options to initiate a shutdown on various criteria, the AP9617 does not. As long as you don't have PCNS clients, don't manually initiate a shutdown, and don't use simple signaling, you should be good.
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