APC Symmetra PX160 short-time load drop

[BillP]

This question was originally posted by Nick on APC forums on 3/4/2019

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Hi, All.

There is one small (up 70kW of IT Load) DC with two independent utility source followed by ATys m ATS and Symmetra PX160 UPS for protect critical load.  

Some weeks ago, all IT load was dropped by Symmetra for 5-10 seconds.
This incident coinced with some issues at 10kV side and loss of Source 1 (for 2-3 hrs).
Some anomalies also expirienced on Source 2 at the same time (input power troubles were recovered in CRACS control unit logs), but no longer than 20-30 second and therefore wasn't registered by DataCenter Expert monitoring system (poll period = 1 minutes).

All load (IT under UPS and CRACS without UPS) was on the Source 2 at the time of issues.

So, all critical load was unexpectedly dropped for short time period, but no alarm events there found at Symmetra's PX display as no events in event.txt file downloaded from NMC. Only usual NTP updates..

Symmetra MIM logs shows some alarm messages (quoted below)

Any idea or suggestions? Thanx

 0600D07F EXSG  D Operate Q003 ok                          YY/MM/DD 09:47:14 654

0900A05E IM    A IM oper. mode: Shift to ONLINE           YY/MM/DD 09:47:14 628

0100D13E IM    D TIM has SBS on                           YY/MM/DD 09:47:14 628

0100A12E IM    A TIM has Inverter on                      YY/MM/DD 09:47:14 628

0100D57E IM    D Inverter sync. error                     YY/MM/DD 09:47:12 672

0280D24E PM 08 D Output RMS voltage fail                  YY/MM/DD 09:47:11 984

0280D23E PM 08 D Inverter RMS voltage fail                YY/MM/DD 09:47:11 984

0270D24E PM 07 D Output RMS voltage fail                  YY/MM/DD 09:47:11 931

0270D23E PM 07 D Inverter RMS voltage fail                YY/MM/DD 09:47:11 931

0260D24E PM 06 D Output RMS voltage fail                  YY/MM/DD 09:47:11 877

0260D23E PM 06 D Inverter RMS voltage fail                YY/MM/DD 09:47:11 877

0250D24E PM 05 D Output RMS voltage fail                  YY/MM/DD 09:47:11 825

0250D23E PM 05 D Inverter RMS voltage fail                YY/MM/DD 09:47:11 825

0240D24E PM 04 D Output RMS voltage fail                  YY/MM/DD 09:47:11 772

0240D23E PM 04 D Inverter RMS voltage fail                YY/MM/DD 09:47:11 772

0500A32E SBS   A Backfeed Contactor closed                YY/MM/DD 09:47:11 704

02A0D24E PM 10 D Output RMS voltage fail                  YY/MM/DD 09:47:11 672

02A0D23E PM 10 D Inverter RMS voltage fail                YY/MM/DD 09:47:11 672

0100D04E IM    D Output voltage error                     YY/MM/DD 09:47:11 624

0290D24E PM 09 D Output RMS voltage fail                  YY/MM/DD 09:47:11 619

0290D23E PM 09 D Inverter RMS voltage fail                YY/MM/DD 09:47:11 619

0100D02E IM    D Bypass voltage error                     YY/MM/DD 09:47:09 668

0240A24E PM 04 A Output RMS voltage fail                  YY/MM/DD 09:47:09 420

0240A23E PM 04 A Inverter RMS voltage fail                YY/MM/DD 09:47:09 420

0500D32E SBS   D Backfeed Contactor closed                YY/MM/DD 09:47:09 352

02A0A24E PM 10 A Output RMS voltage fail                  YY/MM/DD 09:47:09 315

02A0A23E PM 10 A Inverter RMS voltage fail                YY/MM/DD 09:47:09 315

0290A24E PM 09 A Output RMS voltage fail                  YY/MM/DD 09:47:09 263

0290A23E PM 09 A Inverter RMS voltage fail                YY/MM/DD 09:47:09 263

0280A24E PM 08 A Output RMS voltage fail                  YY/MM/DD 09:47:09 210

0280A23E PM 08 A Inverter RMS voltage fail                YY/MM/DD 09:47:09 210

0270A24E PM 07 A Output RMS voltage fail                  YY/MM/DD 09:47:09 158

0270A23E PM 07 A Inverter RMS voltage fail                YY/MM/DD 09:47:09 158

0260A24E PM 06 A Output RMS voltage fail                  YY/MM/DD 09:47:09 105

0260A23E PM 06 A Inverter RMS voltage fail                YY/MM/DD 09:47:09 105

0250A24E PM 05 A Output RMS voltage fail                  YY/MM/DD 09:47:09 053

0250A23E PM 05 A Inverter RMS voltage fail                YY/MM/DD 09:47:09 053

0600A07F EXSG  A Operate Q003 ok                          YY/MM/DD 09:47:08 966

0900A07E IM    A IM oper. mode: Shift to TEMP BYPASS      YY/MM/DD 09:47:08 924

0100A13E IM    A TIM has SBS on                           YY/MM/DD 09:47:08 924

0100D12E IM    D TIM has Inverter off                     YY/MM/DD 09:47:08 924

0100A57E IM    A Inverter sync. error                     YY/MM/DD 09:47:08 510

[BillP · Accepted solution]

This reply was originally posted by Bill on APC forums on 3/5/2019

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Hi,

Sorry for the inconvenience. I have asked that someone from regional 3 phase support team contact you concerning this matter.