APC AP7721 Query

[Anonymous user]

Hi,

We recently had a power failure and one of the sources was turned off during the outage. The ATS would not transfer to the working source due to a problem with the alternate source power. Error in the logs was.. +"Automatic "Transfer Switch: Under frequency violation on Source B."+. Logs on the UPS show the frequency to be fine... should be 50hz but never dropped below 49 or above 51. The logs do only log every 10 minutes but there are no logs for any wierd things apart from the power outage.

On the ATS there is a frequency deviation option.. what does the different options mean? 1, 2, 3 Hz? Its currently set to 2.

The UPSs linked to the ATS are APC products.. APC Smart-UPS RT 10,000VA RM and Symmetra LX 16000 RM.

regards,

Adrian

[BillP]

i dont see the frequency fault anywhere in the log you posted. did you cut it out of the log you posted?

[Anonymous user]

Hi,

We recently had a power failure and one of the sources was turned off during the outage. The ATS would not transfer to the working source due to a problem with the alternate source power. Error in the logs was.. +"Automatic "Transfer Switch: Under frequency violation on Source B."+. Logs on the UPS show the frequency to be fine... should be 50hz but never dropped below 49 or above 51. The logs do only log every 10 minutes but there are no logs for any wierd things apart from the power outage.

On the ATS there is a frequency deviation option.. what does the different options mean? 1, 2, 3 Hz? Its currently set to 2.

The UPSs linked to the ATS are APC products.. APC Smart-UPS RT 10,000VA RM and Symmetra LX 16000 RM.

regards,

Adrian

[BillP]

the frequency deviation is how far from the nominal frequency the ATS will allow. if the frequency is 50Hz, the ATS will overlook a deviation of +/- 2 Hz. Can you post to us the event and data log? you can follow [these instructions|http://nam-en.apc.com/cgi-bin/nam_en.cfg/php/enduser/std_adp.php?p_faqid=9321] to post the text files here for review. based on those, we might need the config.ini file which you can open in a text editor and pull out any user names, passwords, etc before posting or you can wait and ill let you know if we absolutely need it.

thanks.

[Anonymous user · Accepted solution]

Not all the ATSs showed the frequency error, just that the power was faulty.

I found the one that did...

10.11.2009 09:34:53 Automatic Transfer Switch: ATS has switched source. Source A is current source.
10.11.2009 09:34:26 Automatic Transfer Switch: Under frequency violation cleared on Source A.
10.11.2009 09:34:24 Automatic Transfer Switch: Fault cleared on Source A.
10.11.2009 09:34:23 Automatic Transfer Switch: Redundancy has been restored. Source A is available.
{color:#ff0000}10.11.2009 09:34:20 Automatic Transfer Switch: Under frequency violation on Source A.
{color}10.11.2009 09:34:20 Automatic Transfer Switch: Fault exists on Source A.
10.11.2009 08:42:52 Automatic Transfer Switch: ATS has lost redundancy. Source A is not available.
10.11.2009 08:42:52 Automatic Transfer Switch: ATS Communication established.
10.11.2009 08:42:38 Automatic Transfer Switch: 7-Segment display hardware initialized.
10.11.2009 08:42:38 Automatic Transfer Switch: Phase Leds/Push-button hardware initialized.
10.11.2009 08:42:26 System: Network service started. System IP is 10.10.1.219 from manually configured settings.
10.11.2009 08:42:26 System: Coldstart.
10.11.2009 08:37:28 Automatic Transfer Switch: Fault cleared on Source B.
10.11.2009 08:37:21 Automatic Transfer Switch: Under frequency violation cleared on Source B.
10.11.2009 08:37:21 Automatic Transfer Switch: Fault exists on Source B.
{color:#ff0000}10.11.2009 08:36:56 Automatic Transfer Switch: Under frequency violation on Source B.{color}{color:#ff0000}
{color}10.11.2009 08:34:21 Automatic Transfer Switch: Fault cleared on Source B.
10.11.2009 08:34:18 Automatic Transfer Switch: ATS has switched source. Source B is current source.
10.11.2009 08:34:07 Automatic Transfer Switch: Fault exists on Source B.
10.11.2009 08:34:06 Automatic Transfer Switch: Fault exists on Source A.
10.11.2009 08:33:59 Automatic Transfer Switch: ATS has switched source. Source A is current source.
10.11.2009 08:33:48 Automatic Transfer Switch: ATS has lost redundancy. Source A is not available.
10.11.2009 08:33:48 Automatic Transfer Switch: ATS has switched source. Source B is current source.

[BillP]

hm ok. it seems as though the problem cleared very quickly and maybe the data log did not catch it (the data logging interval is 10 minutes) because as you say, in the data log you provided, there is nothing outside of 49 or 50 Hz and with your frequency deviation at 2 Hz, it should have stayed on the preferred source. how many ATSs had this issue?

unfortunately, there is no way to go back and actually measure the frequency when it had an issue of course but you haven't seen any other issues since then, correct?

[Anonymous user]

There hasnt been any issues since but the problem was that the ATS wouldnt switch to the only power source or supply power to the devices.(1 out of 4) We had to unplug everything and use a normal single power PDU to get things going. During the power outage on of the circuit breakers on a UPS switched itself off, which I didnt think they could do, and so we lost power to one source on the ATS. The logs show this a few times... not sure whats happening there. Once I found that source B was actually off at the UPS, when I turned it back on, the ATS worked as it should, supply power and was switchable from the from button.

Will an ATS switch to a source it declares as "bad" or faulty?

[BillP]

it won't if its out of range (frequency or voltage being bad). the only scenario i can think of where it will still switch where you may notice an "error" is if your sources are reported as asynchronous - meaning out of phase basically. the ATS may report they are out of sync but the ATS will switch between the sources.

so yes, if the voltage and/or frequency is out of range the ATS will not switch or will even turn off if it is the only source available. the ATS needs one good source to power up.

[Anonymous user]

All of our ATSs reported bad power during the outage. Does this mean our brand new APC UPSs arent doing what they are meant to be doing? Like filter the power and supply clean power, even during an outage? 10kVA SMART RT UPS and Symmetra 12kVA.

[BillP]

do you have any of the logs from those devices?

[Anonymous user]

The UPS logs dont show anything apart from the power going out and the power coming back on.. nothing else. The data log doesnt show anything bizarre with power or frequency.

One thing I notice while looking at things.. the default voltage setting is 230V... yet the default power output of a UPS is 240V. So Ive upped the voltage to 240 and the deviation to 3.

I have a couple replacement ATSs from APC btu they are faulty as one source reports 240V and the same power in the other source shows 264V... on both units.

10kVA Log
10.11.2009 08:37:52 UPS: No longer on battery power.
10.11.2009 08:37:40 UPS: On battery power in response to an input power problem.
10.11.2009 08:34:43 UPS: No longer on battery power.
10.11.2009 08:34:34 UPS: On battery power in response to an input power problem.
10.11.2009 08:34:30 UPS: No longer on battery power.
10.11.2009 08:34:24 UPS: On battery power in response to an input power problem.

Symmetra Log
10.11.2009 08:35:03 UPS: No longer on battery power.
10.11.2009 08:35:01 UPS: On battery power in response to an input power problem.

Times might not be the same 😛

2nd Symmetra
11.10.2009 10:55:46 UPS: No longer on battery power.
11.10.2009 09:24:17 UPS: On battery power in response to an input power problem.
11.10.2009 09:24:16 UPS: Restored the local network management interface-to-UPS communication.
11.10.2009 09:23:47 System: Network service started. System IP is 10.10.1.200 from manually configured settings.
11.10.2009 09:23:47 System: Warmstart.
11.10.2009 09:14:34 UPS: On battery power in response to an input power problem.

2nd 10kVA Log
10.11.2009 08:38:11 UPS: No longer on battery power.
10.11.2009 08:38:00 UPS: On battery power in response to an input power problem.
10.11.2009 08:35:02 UPS: No longer on battery power.
10.11.2009 08:34:53 UPS: On battery power in response to an input power problem.
10.11.2009 08:34:49 UPS: No longer on battery power.
10.11.2009 08:34:44 UPS: On battery power in response to an input power problem.

The warm restart in the 2nd Symmetra log cant be good.

[BillP]

ahh ok. you'd want to get those ATSs replaced.

also, a warmstart is explained here, its not necessarily a major problem. it might have just rebooted if the card got stuck on a certain process or something like that and restarted itself to clear out.

anyway, good catch on the input voltage. this could have eventually given you bypass out of range messages or something along those lines because of the voltage difference.

anyway i cant really see anything that would have caused this message to be honest. the settings you changed are appropriate for what you described - input should match output for most part.