APC Smart-UPS 2200 Rackmount XL with Backup Generator

Anonymous user · ‎2021-06-29

I have two customers with the APC 2200s. The backups have worked fine and when power goes out gives them about 20 minutes of run time. However, recently my customers have had stationary propane powered generators installed. When power goes out the battery backups come on line as expected but when the generator comes on line the APC starts to rapidly oscillate between line and battery power. I've checked line voltage at the receptacle the APC is plugged into and it is about 115V with the generator running. I also used an analog volt meter to see if there was a lot of flucuation going on; about 1 or 2 volts. I've had my customers shut down all other devises on the generator circuits to see if we were too close to capacity but no change. I spoke with another IT support consultant and he said he has seen that with some of his clients but never found a cause or solution. Was wondering if anyone else has seen this and of course even better, a solution. Thanks.

BillP · ‎2021-06-29

usually with generators, especially when they start up, they output dirty power and maybe a little noise. so the UPS switches back and forth from online to on battery.

assuming the generator is sized properly (should be 1.5-3x the size of your load thats on it), the first thing you will want to check is the "sensitivity" setting of these UPSs. you can do this a couple of different ways.

1. on the back of the UPSs, there should be a green sensitivity LED and a white button next to it. you may need a pen or paper clip to push it. you can adjust the sensitivity this way. it will be bright when the sensitivity is high, dimmer when it is medium and off when the sensitivity is low. you probably want to start with medium and see how that goes, and put it to low if that doesnt work.

2.) if these have any software or network management cards installed, you can change this setting through the software.

[here is an article on sensitivity just to give you a background|http://nam-en.apc.com/cgi-bin/nam_en.cfg/php/enduser/std_adp.php?p_faqid=62]

See Answer In Context

BillP · ‎2021-06-29

usually with generators, especially when they start up, they output dirty power and maybe a little noise. so the UPS switches back and forth from online to on battery.

assuming the generator is sized properly (should be 1.5-3x the size of your load thats on it), the first thing you will want to check is the "sensitivity" setting of these UPSs. you can do this a couple of different ways.

1. on the back of the UPSs, there should be a green sensitivity LED and a white button next to it. you may need a pen or paper clip to push it. you can adjust the sensitivity this way. it will be bright when the sensitivity is high, dimmer when it is medium and off when the sensitivity is low. you probably want to start with medium and see how that goes, and put it to low if that doesnt work.

2.) if these have any software or network management cards installed, you can change this setting through the software.

[here is an article on sensitivity just to give you a background|http://nam-en.apc.com/cgi-bin/nam_en.cfg/php/enduser/std_adp.php?p_faqid=62]