Symmetra LX 16kVA - XR FAULT ERROR?

[upsit_apc]

This was originally posted on APC forums on 7/24/2015

---

UPS is running on 4 battery modules plus XR with 3 battery modules, suddenly UPS started to beep with notification E7 / 02  and communication software report said; XR FRAME FAULT

despite in properties of main battery and XR batteries seems all  in perfect condition with no single error ?!?!

USP works fine, runtime is still like before, all the batteries (changed a year ago, brand new original) are in perfect condition, (measured voltage and capacity inside the each module (pack of 10 batteries per module), input and output voltages are fine....all the tests are passing OK, nothing really changed but only this beep sound and E7 error is showing...

i have tried to reseat the RJ11 comm plug on both sides, all seems fine, but erorr is beeping for XR FRAME

that happened simple like out of blue.....it was all working fine and suddenly we heard beep signal....i am confused....

[BillP]

This reply was originally posted by David on APC forums on 7/24/2015

---

Hello Vlad,

An E7 on an LX XR frame indicates a communication problem. This could either be the RJ9 communication cable, the XR COM card on the XR frame, or any module in the main unit that could be failing and causing COM problems.

If it was the later it would be evident as you would be getting other types of faults on the main unit and/or the powerview display would be acting up. But that does not sound like your case.

The other 2 possible scenarios should be investigated. The RJ9 communication cable is 4 pin straight through cable. You could try swapping that out if you have another. If that is not the issue (I very rarely, if ever, see the problem originating from the cable) then the XR COM card would be suspect. This card is the SYAFSU16.

If I were you I would place the LX into maintenance bypass using the bypass switch on the front of the unit. Then I would go around back of the UPS and toggle the System Enable switch. Flip it down and wait a few seconds and then flip it back up. As long as you are in maintenance bypass and there are no faults on the LX itself (not the XR frame) you can safely perform this task without risk of dropping your load. This will essentially refresh the COM bus on the LX and might clear the fault. If the fault does not clear or returns you would need to look at replacing the SYAFSU16.

[Terry_Kennedy_apc · Accepted solution]

This was originally posted on APC forums on 7/25/2015

---

I have some 20-year-old Matrix units (with modern batteries) and I've had to replace the RJ cables a couple times (actually, I just cut off the ends and crimp new connectors on). Usually just unplugging the cables and blowing the dust out of the jack and wiping the plugs with a dry paper towel will clear things up for a while.

The RJ just carries information about the number of battery packs and battery health - the actual battery power goes though the heavy Anderson connector. As long as the UPS relies on the battery voltage to determine when to shut down due to low battery, the actual runtime isn't affected by problems with the RJ cables. The displayed runtime, of course, will be inaccurate and you get alarms about communication faults and/or changing numbers of battery packs.