PowerChute 3.0.2 data accuracy?

[BillP]

Hi;

I have a BR800BLK that is 8 years old this month. I recently replaced the battery set with an SPS brand. Now I am starting to notice that the BR800 is switching briefly (<5sec) from AC to battery power, even though line voltage has not been interrupted.

i ran the self-test from the PowerChute software and the BR800 passed the test.
Battery status is being reported as 100% charged, and the load is only about 150W, with about 40min backup time.

While viewing the current status tab in Powerchute, I noticed that the line voltage was fluctuating from 125V most of the time, to between 115V and 120V for brief periods.
I was monitoring the line voltage on a DMM during the time I saw the fluctuations in Powerchute, and there was no fluctuation at all on the DMM. It was reading a steady 123.7V.
On the powerchute performance tab, no power problems have been reported, despite the BR800 switching briefly to battery while I had the software open. But both the Br800 and powerchute  do indicate that it has switched to battery when it does.

These events appear to happen in clusters. I heard it switch to battery at least once this morning before I had my computer turned on, then it happened again while I was using the computer but did not have APC services running. I then started the services and opened Powerchute to see if I could learn anything, but so far I have not.

About the apparently erroneous voltage fluctuations; could this be the source of the brief switch-overs? But I have the sensitivity set to medium, which sets the high limit to 139V and the low to 102V, neither of which I have observed in Powerchute during an event.

I do recall that, before I changed the battery, the BR800 was switching to battery often, and also for brief periods like it is doing today. Eventually, the unit would not supply any power, either from AC mains or battery, so I changed the battery. That fixed the problem.

So what do you think? Is it time for a new UPS? I had considered replacing it before I decided to replace the battery, but I am now beginning to second guess my decision not to replace the BR800.

I would appreciate your suggestions/ideas.

Thanks

[BillP]

Hi,

PowerChute will only report the data that is received from the UPS. Try setting the sensitivity to low and monitor it. If that does not help and the voltage is not fluctuating but the UPS is reporting it then it may be time to replace it. 

As for PowerChute not recording the switch to battery, this may happen if the switch is less than 4 - 5 seconds. 

[BillP · Accepted solution]

Hi Bill;

I have set the sensitivity to low. This has apparently solved my problems with the BR800. But I wanted to do some more extensive testing using a variac (or the type thas is only a variable transformer, and therefore does not introduce waveform distortion or noise into the BR800). I found that the switch-over from AC to battery always occurs at a much lower voltage than the low setting in PowerChute. For example; when PowerChute is set to low sensitivity, and voltage setting of 100/139, the switch from AC to battery occurs at 78.5V, and switches back to AC at 83.5V. When I ran my tests, I set the variac using a DMM connected to the input of the BR800, and once adjusted, I let it sit at that voltage for several minutes to find whether the BR800 would switch after time.

Interestingly, if I set the low voltage in PowerChute to 104V, the switchover from AC to battery occurred at 78.2V, and switch back to AC at B.

When sensitivity was changed to medium, with low voltage set to 104V, switchover from AC to battery occurred at 88.0V, and switch back to AC at 94.1V.

When sensitivity is set to high, I was unable to collect data, as the BR800 switched erratically at almost all voltages between 100V and 130V.

Then, there is this really strange behaviour which the BR800 exhibits under very specific conditions:
If sensitivity is set to high, and the input voltage is brought to about 128V, the BR800 will switch back and forth several times, but then it will latch up in the battery mode, and remain there until the input voltage is lowered to around 127V. It did not appear to make any difference what the voltage settings in PCP were.

None of these problems occur when sensitivity is set to low, which is where I am going to leave it.

Thinking that this issue could be caused by line noise, I installed two clamp-on ferrites onto the BR800 line cord at various points. There was no change in occurrence of the problem. I do not know what the value of these ferrites was, although I do have the means to test them if you want me to. I thought I might want to try other ferrites, selected for the most common line noise that might be present. Unfortunately, I have no means of analyzing the AC line for noise, except to try different chokes.

The last thing I tried was to disconnect all of the battery backed-up loads from the BR800. But the BR800 continued to exhibit the problem.
Note that all of the problems occur when the sensitivity setting is at medium or high, with the most frequent of course at high.

Unless you have something further I should try for the problem, I am going to leave the sensitivity set to low. I will keep you informed if there are any changes.

FW