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Need help choosing a UPS (plus general UPS tips)
Pentium100:
--- Quote from: AnimeJanai on May 19, 2012, 10:29:39 PM ---While the APC unit puts out a good simulation, it is by no means the same as a pure sine wave.
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Actually, the big APC Smart-UPS devices create quite good sine wave. AC motors work perfectly (without any buzzing) and an UPS plugged into the output of another UPS works normally. If you plug a UPS into the output of a cheap UPS, then both units will go on battery at the same time, because the UPS will detect the square wave as "unacceptabele". However, I have not used an oscilloscope to see how the waveform looks like or measured the THD, so I cannot say for certain, but for all connected devices it is as good as the mains.
--- Quote ---Of course, APC could take that wattmeter feature away with newer units; I haven't bought one for 3 years now since the batteries in them all seem to be going strong yet.
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No need to replace the whole UPS when the battery dies - just replace the battery, the majority of UPSs use standard lead-acid batteries and quite a few manufacturers make them. No need to buy from APC or other UPS manufacturer.
--- Quote ---My oldest APC big units have dual massive batteries and my plastic brick ones have smaller batteries but the same advertised run time.
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My biggest UPS (2200VA) has four 12V/18Ah batteries. Maybe the newer models are more efficient. Or maybe they are over-discharging the batteries and damaging them.
nstgc:
--- Quote from: Pentium100 on May 15, 2012, 04:45:16 AM ---When the batteries in one of my UPSs become bad, I replace them and then test them individually, those that are truly bad (no current at all) get sold for recycling, batteries with a shorted cell (10V instead of 12) can still be used for lights, but will become bad soon (as I do not have a 10V charger) and those with increased internal resistance (voltage drops a lot when under load) can still be used for small loads or loads that do not need precise voltage (lights, audio etc).
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There are places that buy old UPS batteries...nice. Any good ones online, because I'm not sure any one locally would do that.
@ Janai: I didn't want to take any chances so I baught a SUA1500 which produces a "pure" sine wave (PWM + capacitor). Its pricy and I don't have whatever bad ass job you seem to have so I'm buying batteries.
--- Quote from: Pentium100 on May 20, 2012, 03:58:22 AM ---
--- Quote from: AnimeJanai on May 19, 2012, 10:29:39 PM ---While the APC unit puts out a good simulation, it is by no means the same as a pure sine wave.
--- End quote ---
Actually, the big APC Smart-UPS devices create quite good sine wave. AC motors work perfectly (without any buzzing) and an UPS plugged into the output of another UPS works normally. If you plug a UPS into the output of a cheap UPS, then both units will go on battery at the same time, because the UPS will detect the square wave as "unacceptabele". However, I have not used an oscilloscope to see how the waveform looks like or measured the THD, so I cannot say for certain, but for all connected devices it is as good as the mains.
--- End quote ---
I still see no reason for me to plug a surge suppressor into the out put of a UPS. Shouldn't it be fine if I have it on the input (which is how its currently set up)?
Pentium100:
--- Quote from: nstgc on May 21, 2012, 03:09:27 AM ---There are places that buy old UPS batteries...nice. Any good ones online, because I'm not sure any one locally would do that.
--- End quote ---
Shipping a heavy battery will cost more than you will get for the lead. Like with paper, those places don't pay a lot, but still, it's better than just give it away for free.
--- Quote ---I still see no reason for me to plug a surge suppressor into the out put of a UPS. Shouldn't it be fine if I have it on the input (which is how its currently set up)?
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I agree, it is pointless to plug a surge suppressor into the output of a UPS. Well, unless it is the only unused "extension cord" you have, then you could save some money by using it as it will not be worse than using a regular extension cord.
AnimeJanai:
--- Quote from: nstgc ---I still see no reason for me to plug a surge suppressor into the out put of a UPS. Shouldn't it be fine if I have it on the input (which is how its currently set up)?
--- End quote ---
Reread carefully. That is not what was said by either datora or myself.
Do not do that. As datora said, and I also said (after having a bad experience), it is bad. There is no problem to put the surge suppressor in front of the UPS (between the UPS and the wall socket). But you should NOT put the surge suppressor on the battery-powered outputs of the UPS.
nstgc:
Right. THe UPS is plugged into the SP which is plugged into the wall.
[edit]
I just saw this:
--- Quote from: APC link=http://nam-en.apc.com/app/answers/detail/a_id/1372 ---Plugging your UPS into a surge protector: In order for your UPS to get the best power available, you should plug your UPS directly into the wall receptacle. Plugging your UPS into a surge protector may cause the UPS to go to battery often when it normally should remain online. This is because other, more powerful equipment may draw necessary voltage away from the UPS which it requires to remain online.
--- End quote ---
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