Was System Abend Due to the UPS, or the Sense Cable or the iSeries?

In July 2007, our 9406-520 system performed a PWRDWNSYS after the lights flickered because it said the Powerware 9910-P33 issued a low battery condition signal. The UPS itself never indicated a low battery condition and EATON Corporation replaced the UPS free of charge. I installed the replacement UPS on a weekend and tested it by disconnecting utility power several times. As expected, the iSeries indicated each time the utility power failed and was restored.

This past Saturday at 04:30:22, our iSeries abended because it sensed a utility power failure. When I arrived on site at 6 A.M., both our production LPARs were deactivated but the UPS (the replacement installed in July) appeared to be operating normally. Eaton Corporation again offered to replace the UPS. None of our other 25 servers showed any indication of a power failure and I don't believe there was one.

I disconnected the sense cable and the iseries recognized this by issuing a message so I know that the iSeries at least knows when it's there. I'm going to leave it disconnected until I find the root of this problem.

Neither Powerware, nor IBM software support, nor IBM hardware support could pin point why these events occurred and I'd like your input on the following:

1. Should I test the UPS, sense cable, and iSeries on a Sunday when I can put both partitions system in restricted mode.?
2. Hire a technician to determine the status of the UPS first?
3. Replace the sense cable?
4. Install management software for the UPS?
5. Buy a Tripp-Lite?
6. Eliminate the sense cable? We haven't needed it in at least 9 years.

Bryan Burns
iSeries Specialist
ECHO, Incorporated
Lake Zurich, Illinois