Symmetra LX 16000 stuck in bypass

[cbwapc]

Hi,

I have a Symmetra LX 16000 that has been in a strange state since we had a 30 second power outage.  During that outage, all power failed to the servers it was supplying power to, despite the fact that the batteries power should have been sufficient and the unit was not showing any faults at that time.  When the power came back, the UPS did not.  By toggling the back "System" switch, I was able to get the UPS back up and then place it into bypass mode to return power to our servers.

However, at that point the UPS started showing 3 critical alarms.

3 Critical Alarms Present

The output voltage is outside its defined limits.
A battery fault exists.
At least one faulty battery exists.

Additionally, the logs would report a battery failure followed quickly by a recovery and the same failure/recovery for a power module.  However, the logs would not point to a specific battery or power module, and a "status" check showed all power modules and batteries to be "OK".

After upgrading all firmware to the latest versions, the failures in the logs stopped, but the alarms remained.  When I tried to run a self-test, I was informed that that could not be done while the unit was in bypass mode.  When I attempted to have it leave bypass mode, the front panel shows the error:

"UPS unable to exit bypass due to overload or fault"

On the assumption that I may have some kind of "silent" failure on a module, I attempted to sequentially pull each battery and power module to see if I could clear the error and get the UPS out of bypass mode, but did have any effect. 

At this point, the logs are not showing any issues.

I feel like the next step is to have a technician come out and service the unit, but if there are any other steps I should be performing to resolve this situation before then I'd very appreciate any advice.  I'm happy to provide any files/logs.

[KarimEissa · Accepted solution]

Dear,

This error is displayed when the intelligence modules detect that the bypass contactor(s) is not in the
position that it should be in. This will only be displayed while the UPS is in bypass or after the UPS has
been in bypass. This fault would not affect the ability to transfer to maintenance bypass; however, keep
in mind that when the UPS exits maintenance bypass it initially transfers to automatic bypass before it
goes online. It is possible to drop the customers load if there is a bypass contactor fault while
attempting to exit maintenance bypass. It is recommended that you inform the customer of this risk
before attempting any troubleshooting.

-There are several bypass related faults that may appear in
either the IM failure sections or System failures sections
-Ensure that the intelligence modules have a serial datecode of 0840 or later. Intelligence modules
manufactured before that can cause bypass related issues. See FA157651 for details

-If the UPS is already in maintenance bypass, install the intelligence modules one at a time, cycling the
system enable switch after each one is installed.

- If possible, visually inspect the AC slide tray to see if the bypass contactor(s) is stuck or there are any
loose connections. Replace the slidetray if it is suspected that the contactor is bad.

- Bypass control and sense wires are connected to the AC slide tray and backplane via a Molex
connector. It is possible that this connection is loose or not making good contact, reseat the slide tray in
order to verify that the connection is OK. This will require a total power off of the Symmetra LX

so if the issue still not resolved the AC tray might need to be replaced after verifying the raw status data by the CCC team and performing the troubleshooting above

Regards,

Karim