Can I test or operate APC Smart UPS 2200 off a single RBC7

[vsmGuy]

Originally Posted by Behemot

Well isn't it obvious the UPS will be buzzing under all circuimstances? You have huge 50/60 Hz transformer inside, you cannot totally avoid resonance. What I have seen so far, when it operates on batteries, the buzzing is much worse.

Attached is a clip of the sound that comes from the 22uF, 150V bipolar yellow capacitor(s) in both the models when charging the batteries.

At 45s into the recording, I turn off the line power - notice how the noise goes away completely when it's running off batteries in the 1000VA (the one which was running when I recorded the noise)

I am sure you will agree this is very different from the gentle hum of a transformer?

If this is a characteristic sound of APC UPS when the batteries are dying, I would like to know if there's a battery I can buy, from say Walmart or Home Depot etc just to see if a new battery makes the noise go away.

[vsmGuy]

Originally Posted by budm

L5-30 (120v 30A, 3-WIRE) Twisted lock. How did you wire it up? Black (Hot) should go to the brass screw (L), White (Neutral) should go the Chrome screw (N), Green(Safety Ground) should go to Green screw.

Oh - got the polarities reversed. Thank you for this detail.

Awkward enough: I looked around a few hardware stores and no one seemed to have a screw on type standard AC male type plug - all were molded (I wanted to replace the L5-30 with standard AC male type plug).

[Behemot]

Originally Posted by vsmGuy

Attached is a clip of the sound that comes from the 22uF, 150V bipolar yellow capacitor(s) in both the models when charging the batteries.

At 45s into the recording, I turn off the line power - notice how the noise goes away completely when it's running off batteries in the 1000VA (the one which was running when I recorded the noise)

I am sure you will agree this is very different from the gentle hum of a transformer?

If this is a characteristic sound of APC UPS when the batteries are dying, I would like to know if there's a battery I can buy, from say Walmart or Home Depot etc just to see if a new battery makes the noise go away.

Ah, you mean this. I heard that too with two BackUPS (those are the power cords with battery) and yes, both had pretty much dead batteries. Swaped for good (well, with 2/5 of nominal capacity, but working normally) just for testing and it was OK again.

[vsmGuy]

Originally Posted by Behemot

Ah, you mean this. I heard that too with two BackUPS (those are the power cords with battery) and yes, both had pretty much dead batteries. Swaped for good (well, with 2/5 of nominal capacity, but working normally) just for testing and it was OK again.

Don't get me started with the BackUPS - for some reason these seem to be the only kind APC now sells to consumer retail

Anyways, if the batteries are the problem, could you recommend something I can buy, from say Walmart or Home Depot etc just to check if a new battery makes the noise go away?

I wish you were in SoCal so I could loan a set from you to put into my UPS to check

BTW - If these batteries are the problem, how do they manage to still give me ~2hours runtime @100+W continuous load?

[Behemot]

I you plan to work with the UPSes more - I think it can be turned into some weekend business (since 98 % of the problems are battery wise, yet people often sell "dead" UPSes with "don't know whether it works" status and you can "repair" them with just new batts and resell for much more) - I recommend geting some like 5 Ah. Panasonic has good quality, try for example LC-R12V4P.

[vsmGuy]

Originally Posted by Behemot

I you plan to work with the UPSes more - I think it can be turned into some weekend business (since 98 % of the problems are battery wise, yet people often sell "dead" UPSes with "don't know whether it works" status and you can "repair" them with just new batts and resell for much more) - I recommend geting some like 5 Ah. Panasonic has good quality, try for example LC-R12V4P.

When you mentioned "2/5 of nominal capacity, but working normally" did you mean "2/5 of AH rating" but correct voltage?

[Behemot]

Yep, 5 Ah nominal, ~2 Ah calculated from runtime.

[vsmGuy]

Originally Posted by Behemot

Ah, you mean this. I heard that too with two BackUPS (those are the power cords with battery) and yes, both had pretty much dead batteries. Swaped for good (well, with 2/5 of nominal capacity, but working normally) just for testing and it was OK again.

Unfortunately for me, the noise remains even after trying with new batteries.

I went to Walmart and got 4x12V car batteries. I don't know their AH rating, but it was just meant to check if new batteries yield same noise in the UPS.

I am not sure if the impedance of the batteries could be a problem, but I don't want to risk buying "APC compatible RBC7/RBC11" batteries to verify that and end up with the noise not going away even after getting such batteries.

I connected these in series and when I hooked them up - there was NO change in the noise - either in the 1000VA or the 2200VA.

The 2200VA also has a 120mm fan that runs every 5 minutes for a minute, and at night that can be quite a hassle. It seems as if the fan is timed to run like that as the fans runs in that cycle regardless of whether I have room cooling on or off (unless that part is the UPS is already damaged when I got it)

I wish I had an idea (and possibly a solution) to solving the noise (sample I uploaded in this thread).

A hum is OK, but this noise is anything but a hum.

[Behemot]

Can it operate from the batteries? If so, I don't see a problem.

Well, as for the noise, that is really strange. I guess we have to deal with that in the other thread…