Running a pump from a UPS?

[GSerg2]

Does anyone have any information on doing this? I know that most UPS's generate a square waveform or, in the better ones, a modified sine waveform. Is this a problem for pumps?

Specifically I am interested in running a Mag pump or a Maxijet powerhead off a UPS in case of power failure.

Any information is much appreciated.

[grim]

They'll sound like hell (impeller slapping around) but they'll run. Unfortunately, depending on the size of the pump, they might not run very long at all. The hands down best option is actually to run a controllable tunze stream. Because they use DC power, the ragged quasi-AC from the UPS is OK. They consume very little power and can actually last quite a long time on a decent sized UPS. Running an external pump like a midsize Iwaki wouldn't really be recommended, a computer-sized UPS would probably only last a few minutes at most.

jb

[tngarner]

I am running a MAG 12 off of a UPS. It gives me about 18 to 20 min of run time with the power out. Never really thought about the sin wave change.

I have not had any problem but it has only kicked over to battery a few times. I figure the few times that the power goes out if the motor is not getting a true 60Hz wave then it should still be ok. Motors are fairly simple and I am not sure that power that is a bit off from the norm could really hurt it. A voltage drop would more likely hurt it than a frequency change.

[GSerg2]

What about just running a Maxijet powerhead like a 600 or 900? How long would one of those run on a midsized UPS?

[CA]

Running an external pump like a midsize Iwaki wouldn't really be recommended, a computer-sized UPS would probably only last a few minutes at most.
My largest pump uses about 140w, about what a typical modern computer will use. On a 900VA UPS ($100-ish on eBay plus $20 for all new batteries), that should run an hour or two. I'm thinking of putting the refugium loop on one of the 900VA batteries. The pump for that only uses about 100w, so it should give me some decent run time.

On the battery powered air pumps... How many gallons can you keep safe with one? What's a good place to put the airstone?

[GSerg2]

I looked up the Maxijets and the 600 uses 7.5watts, the 900 uses 8.5 watts. I may hook one up to a UPS and see how long it runs just to see if it is worth it. I will post back with my experience.

Btw, I ordered two battery backup air pumps today after reading about the tragedy that struck someone on RC. This is the one I ordered.

http://www.aquariumguys.com/silentairpump.html

[grim]

The numbers never really work out right in real life, so if you go this route, test it yourselves before you put faith in the numbers. You might end up with much less run time than you thought you had.

jb