Random "Redundancy Lost" Messages - Symmetra LX

[Anonymous user]

I have a Symmetra LX with 3 power modules installed. It was installed March 2008.

For the past day I have received several randomly timed sets of the following messages:

[Start]
"UPS: Redundancy Lost"
"UPS: A Redundancy Alarm Threshold Violation Exists"
[Wait exactly 20 seconds]
"UPS: Redundancy Returned"
"UPS: A Redundancy Alarm Threshold Violation No Longer Exists"
[End]

All of these messages show up in this exact order with exactly 20 seconds between the redundancy lost and redundancy returned messages. Unfortunately they are 100% random in timing ... sometimes hours between messages ... sometimes a few minutes. By the time I receive the emails the error condition has already cleared ... so I havent been able to see if there is a specific power module causing the problem.

Everything looks good now ... status on all the power modules, chassis and intelligence modules shows things are in good order.

Any ideas how I can narrow this down? Any way to get to some more detailed log information that might tell me more about the issue? Any ideas are greatly appreciated.

[BillP]

hi - you are exactly right in your second post.

the unit calculates the redundancy based on the load you have on the UPS. it seems as though your load is probably spilling over to that third redundant power module and then dropping back down.

i'd start thinking about an extra power module as well and if there were a problem with any of the modules, it would most likely be a power module fault and you'd be receiving that message too. i have no reason to believe that this is related to nothing more than your load jumping up a bit, causing the UPS to lose that redundant power module, and then going back down once the load clears the threshold and you have redundancy again.

hope this helps!

[Anonymous user · Accepted solution]

Its happening more frequently now ... I had to disable alarm when redundancy goes below n+1 for now (company doesnt pay for the text messages to my phone).

But I got to thinking ...

n+1 redundancy means that even when 3 modules are installed the unit tried to operate the existing load with only 2 modules ... reserving the 3rd one for a failure? In which case could this be caused by a short spike in the load going above what 2 power modules could provide? That would lead me to believe there is nothing wrong with the unit or the power modules ... it just means I need more capacity.

We've been talking about installing the fourth and final module in that unit ... so maybe that would be the catalyst to do it.

Message was edited by: pepsiaddict