Over Voltage Alarms

[Anonymous user]

I have the 750BB on two systems and a 350 r on one system and over this last week have been getting so many shutdowns from over voltage like over 129 volts had to set it to 130 to stop getting the alarms and it funny because when I check the plugs in the house with a volt meter they are never over 125 so are these APC software systems out of wack, so I just up graded all the software to 2.1.1 because the system are Vista Business,Premium,and Ultimate any body else ever run into this problem.

[TheNotoriousKMP_apc]

Hello,

The UPS's sensing the overvoltage is never something that I've seen as being inaccurate. It's possible that the times when the UPS is reporting the overvoltage, that the voltmeter (if a non-true RMS) isn't accurately reading the voltage from the wall. Any jump in voltage like that will definitely trigger the AVR Trim alarm on the UPS. If it is consistently above 122VAC, I would recommend getting the line voltage trimmed, as that is abnormal.

[Anonymous user]

I just checked the voltage and it is 124-125 with the voltmeter and the APC I guess I will call the power co but I am not sure what they are going to do this is a dirty power area I see it as low as 98 in the summer Thanks Have a nice Holiday

[TheNotoriousKMP_apc]

Hello,

They should be able to put some type of Regulator on the line as a tap, to prevent problems when the power on the grid drops that low, or becomes that high. If you are at the end of the grid, they may not be able to do anything, but every other case we've come across, the electric company has been able to put some type of tap on the line to make sure the voltage remains steady.

[Anonymous user]

OP, does it happen as a response to certain appliance in the house being turned on?

The Notorious K.M.P. wrote:
Hello,

The UPS's sensing the overvoltage is never something that I've seen as being inaccurate. It's possible that the times when the UPS is reporting the overvoltage, that the voltmeter (if a non-true RMS) isn't accurately reading the voltage from the wall. Any jump in voltage like that will definitely trigger the AVR Trim alarm on the UPS. If it is consistently above 122VAC, I would recommend getting the line voltage trimmed, as that is abnormal.

True-RMS or not does not matter when you're measuring the voltage of the wall outlet. It's close enough to sinusoidal that an average repsonse(not marked true-RMS) meter responds just fine.

[TheNotoriousKMP_apc]

I understand that the RMS voltmeter may not matter, however, it's a better recommendation then having customers go get a voltmeter to measure voltages, since lately there has been an influx of customers calling with a standard 120/208 voltmeter. That doesn't really help troubleshooting scenarios when your voltmeter will not give you the voltage to 1 decimal place.

[Anonymous user]

It doesn't have to do with anything being turned on its running 127 as I am trying on the APC software and the voltmeter at the wall plug or any other wall plug in the house i thought at first it might be because it is dedicated line I installed for the computers but it doesn't matter which outlet I check they all read pretty much the same.

[Anonymous user]

PP&L showed up today but i was gone and the power was of for 3 minutes so I am not sure what they did but power is down to 123 volts at the APC and receptacle. The meter I use is a Micronta Range Doubler 22-204A have had it for years. Plus I got a reply from APC teck support and he told me to set the APC unit sensitivity to high and set the voltage scale from 97 low to 136 high to get rid of the Alarms and that is what is up with my problem. Thanks all and have a nice Holiday

[TheNotoriousKMP_apc]

Glad they trimmed it down. One last note. Even though the transfer points have changed, because it's a residential area, you may want to keep the sensitivity @ low. That will allow for a wider range of electrical noise/harmonic distortion to be filtered by the UPS to operate online. You may experience less than reasonable transfers to battery for minimum noise on the line.

[Anonymous user]

Thanks Happy Holiday

[Anonymous user]

Any body tell me what are the defaults high and low voltage setting I forget with all this over voltage going on infact they were here again at 3:20 this am and now we are down to 119-120 as I type finally. Thanks for the Help

[TheNotoriousKMP_apc]

Hello,

The first thing I'd like to bring up is that you may want to disable both powerchute Notification Sounds (Under Options) as well as disable the battery back-up to beep between specific hours, so that you are not bothered by power problems.

Secondly, the default is per UPS. I will take a look tomorrow mid-afternoon and see what the default transfer points are for you and repost.

[TheNotoriousKMP_apc]

The default range for a 725 is 97-127. This should be the same for the 750BB.

[Anonymous user]

New update the PPL guy came back again and he had to put a recorder back on the meter head and he finally looked up the guide lines for voltages and he was wrong at 8% he now says it is 5% which makes the high at 126 volts so we will see what up with this new recorder

[Anonymous user]

I have an update for you or whoever is interested. PPL cam out and installed a voltage recorder and left it on for a week to record my voltages. The tec said that he is not sure but the allow 8% up or down in voltage fluctuations so ay 120 volts the high would be 129.6 volts if my math is correct. Waiting for the results plus I just upgraded one of my APC units to the 750G which so far I like the looks and the new features.

[Anonymous user]

I would wonder why my new 750 G the high voltage setting the lowest is 136 and the lowest low setting is 88 and at default it is set at 136 and 97 but I guess low voltage is worse than high voltage so they tell me.

[Anonymous user]

I think the high/low transfer points and voltage regulation range of many UPSes are too strict. Modern power supplies can cope with a much wider fluctuation margin. Specially those with Active PFC, monitors, printers, scanners. thar comes with a power supply able to run from 100-240V in these cases there isn't even the need for an AVR. All monitors now a days work from 100-240V as its nominal voltage, but they can work fine from 90-260V. And those small AC/DC Adapters that is supposed to work off a 120V outlet only, can do this from 100 to 135-40 without any problem. If all your AC/DC Adapters are rated to work from 100-240V don't even hesitate changing the UPS sensitivity to the lowest point.

I'd love to have the choice of choosing whatever transfer point I want via software or via "secret codes" on the UPS itself and a wider margin for voltage regulation or none. I think as power supplies develops, UPS and Voltage regulation manufactures should allow us to do that or ship new units with looser transfer points and regulation.

Message was edited by: rau

[Anonymous user]

They retrieved the voltage unit today so I will have to see what the answer is in days to come.

[Anonymous user · Accepted solution]

I have the 750BB on two systems and a 350 r on one system and over this last week have been getting so many shutdowns from over voltage like over 129 volts had to set it to 130 to stop getting the alarms and it funny because when I check the plugs in the house with a volt meter they are never over 125 so are these APC software systems out of wack, so I just up graded all the software to 2.1.1 because the system are Vista Business,Premium,and Ultimate any body else ever run into this problem.