Two Symmetra PX-80's with unusual PDU alarms/freeze-up

[Anonymous user]

Have a client in our Co-Lo area with three PX-80s , roughly 8 years old... two of them I just noticed have odd-ball PDU cabinet Powerview alarms showing that are a mystery.

UPS-1's PDU powerview is showing an undervoltage alarm event and is "frozen" ...no response to key presses at all except that it Beeps. All status LED's are off except the bottom Fault LED.

UPS-2's PDU powerview has the LED lit for the UPS is in Bypass, and there is a fault condition for all four "User input contacts" -  closed when they normally should be open-  and a fifth fault is showing as UPS in atypical bypass mode.

In both cases the UPS cabinet / powerview is showing no faults; UPS online, load being powered. None of the indicators above the Q1/Q2/Q3 breakers inside the PDU cabinet are illuminated on either UPS. I have in the past power cycled the PDU brain on a PX40 to clear a fault but never on an 80... I found to the two breakers (source #1 and #2) for the PDU brain. Would first try to power cycle the powerview at least on the one that's frozen.

For the brain power cycle wondering whether there is risk of an unexpected EPO if there is a true hardware fault on either of the two PDU brains... ?

Thanks for any tips/advice !

....Dave

[Anonymous user]

Minor Update: I rebooted the powerview that was frozen...it beeped and seemed to do its self-test thing ok at the start, but once it tried to talk to the brain serially all it showed was a series of "9"s, then a few "0"s and then more "9"s across the top of the display, one showing every couple of seconds or so until that first line filled up. It beeps still with keypresses but no indication of any meaningfull connectivity with the brain.

[BillP]

Hi Dave,

I asked our 3 phase support team for any comments. Here is what I got:

UPS-1's PDU  - it does sound like the brain is locked up on this one.  We no longer instruct customers to perform a reset of the brain by turning off the two small breakers in the front (electrical safety concerns with opening a cover on a live PDU without proper Personal Protection Equipment).  However, if anyone was to reset those two breakers to cycle the PDU brain, you would want to ensure the EPO rocker switch on the PDU brain was in the test position.  As long as EPO is in test mode, there is no way for the brain to send out any EPO signals to its input breaker, or to the UPS (even if the brain was locked, confused, or otherwise faulty).

UPS-2's PDU -  Atypical bypass is the state of both Q2 and Q3 being turned on at the same time.  I'm sure your Q3 breaker is not turned on, but it seems possible that the AUX contact that tells the PDU what position the PDU is in may be faulty.  Poke through the PDU powerview and try to find the page that shows the breaker positions, I bet it will show them all closed.

If this is the case, I would suggest taking the UPS to static bypass, so you can safely turn on the Q3 breaker, then turn it right back off again, and then command the UPS out of bypass.  It is possible just toggling the Q3 breaker on and off like this might loosen up the AUX contact.  If that does not work - it is possible the Q3 breaker will need to be replaced. - Unfortunately this repair would require complete downtime - bypass would not be an option.

[Anonymous user · Accepted solution]

Thanks Angela! that's very informative and helpful 🙂

For UPS-1 I can most certainly try  a power cycle on the brain , I remembered that test switch but was worried it may have had a firmware override or something...

For UPS-2 the Powerview says "Q1 & Q3 - UPS Connected" and "Q2 Bypass Enabled".  Q2 is definitely in the off position I put it that way myself (this ups has declining numbers of healthy batteries and "crashed into bypass" the last power dip we had...I had to weed out the dead batteries and was able to get it back online without dropped load). We could try the brief static bypass to try and clear it I will consult with the client.

Thanks again,

Dave