ATS Model AP7723 Events Issue "Over frequency violation"

[Anonymous user]

Back ground Setup:

2 UPSes (Model SURT5000XLI) used as a Source A and B, 03 ATSes(model AP7723) is used to feed power to further racks.
Firmwares for UPS and ATS is already been updated with the latest ver 2.0.3.
Settings(frequency etc) have been set to maximum tolerance value for all 5 equipments.

Scenario
ATS shows following events logs whether it is having input from the source A and B which is itself a UPS, and UPS generates 230V and 50Hz.

02/17/2013 17:57:57 Automatic Transfer Switch: Fault cleared on Source A.
02/17/2013 17:57:55 Automatic Transfer Switch: Redundancy has been restored. Source A is available.
02/17/2013 17:57:55 Automatic Transfer Switch: ATS has switched source. Source A is current source.
02/17/2013 17:57:42 Automatic Transfer Switch: Over frequency violation cleared on Source A.
02/17/2013 17:57:42 Automatic Transfer Switch: Fault exists on Source A.
02/17/2013 17:57:24 Automatic Transfer Switch: ATS has lost redundancy. Source A is not available.
02/17/2013 17:57:24 Automatic Transfer Switch: ATS has switched source. Source B is current source.
02/17/2013 17:57:19 Automatic Transfer Switch: Over frequency violation on Source A.

My question is Why ATS shows faults as voltages and frequency is coming from UPSes.It is observed that at the time of generator or supply outages these messeges are generated but still UPS is there in between main supply and ATS.

Please suggest it is very important to know.

Would be thankful and appreciate quick response
.

[BillP · Accepted solution]

please provide the full event.txt, data.txt and config.ini for review. instructions to download these files are located in the knowledge base (http://www.apc.com/site/support/index.cfm/faq/) in article ID FA156131.