Sizing a UPS

[Orcrone]

Turned off everything on my EB8 with the exception of the gaming adapter for the Apex base unit and a powerhead & pulled the plug to the 450 VA UPS. Found out it's useless so I'll be replacing it. I know the bigger the better. Just wondering what size I'd need to run a pump (Mag18) & heater (200 - 400 watts) for some useful period of time. Or is that not feasible and I should just attempt to keep the powerheads going during a power outage?

 

[aquamanic]

I wouldn't worry about the return pump if you have circulating power heads. Just run them and don't worry about your sump, skimmer, etc. Heaters are real power hogs but you'll have to weigh that against having a power failure during winter months, your house temp, duration, etc.

How fast do you think you can respond to your tank and get supplemental power going like a generator? In my case, I can have that operational in 1 hour from when I decide to do it. I've got things sized to last 2 hours so at hour 1 if there's still no power, I start the process to activate the generator. That's what you have to figure out. Then add up the watts of all the devices and roughly that's your volt/amps (if you want exact, there's website converters that take voltage, efficiency, etc.). Then see what the mfg says the time limit is at that VA rating and go from there.

Being here in Louisiana, its been tested a few times!

 

[Orcrone]

Thanks Alan. So if I want to keep a pump (about 150 watts) and a 300 watt heater going that will require a minimum of 450 VA (more to be safe). Then look to see how long the UPS can run at that power output. I'd assume, all things being equal a 900 VA UPS will keep the same load going twice as long. Or I could keep a powerhead with minimal power usage going much longer.

I work an hour from home and I probably wouldn't leave as soon as the power failed, so I probably need to figure a few hours until the generator's fired up.

 

[nixer]

VA does not apply to ac watts like it does with dc watts.
if i were you i would seriously run your numbers through the apc calculator http://www.apc.com/tools/ups_selector/index.cfm

 

[jrpark22000]

VA does not apply to ac watts like it does with dc watts.
if i were you i would seriously run your numbers through the apc calculator http://www.apc.com/tools/ups_selector/index.cfm

+1. Also once you have calculated the cost to build/buy your UPS powering AC powerheads, you may want to look into a DC output UPS and buying DC powerhead(s). You could possibly gain significant run time be avoiding the AC conversion. This would allow for a smaller cheaper UPS and offset a large portion of the DC powerheads.

Typically your lower end UPS will use a cheap rectifier. You'll lose a lot of usable DC voltage and power under a certain value. A deep cycle marine battery with a battery tender, both under $120 is typically much cheaper and will last much longer. Also try to keep the location of your DC backup as close to the DC powerhead as possible. Long cable runs are DC electricity's enemy. You can add a invertor to the marine battery so you could use a heater.

 

[Orcrone]

+1. Also once you have calculated the cost to build/buy your UPS powering AC powerheads, you may want to look into a DC output UPS and buying DC powerhead(s). You could possibly gain significant run time be avoiding the AC conversion. This would allow for a smaller cheaper UPS and offset a large portion of the DC powerheads.

Typically your lower end UPS will use a cheap rectifier. You'll lose a lot of usable DC voltage and power under a certain value. A deep cycle marine battery with a battery tender, both under $120 is typically much cheaper and will last much longer. Also try to keep the location of your DC backup as close to the DC powerhead as possible. Long cable runs are DC electricity's enemy. You can add a invertor to the marine battery so you could use a heater.

You've given me a lot more to think about. I'll have to do some research. Thanks

 

[swearint]

Here is an old thread where I posted the UPS system that I use.

http://www.reefcentral.com/forums/showthread.php?t=1763957

Todd

 

[kurt_n]

You are not going to find a consumer-grade UPS that will run a heater for any length of time. I'd just concentrate on powerheads.

I run a Xantrex PowerSource 400 which is one of the larger capacity UPS out there... but they don't make them anymore. They still make the PowerSource 1800, which if you have the room will give you a fair amount of time without having to DIY-together inverters and batteries.

 

[RussM]

And to throw another wrench in the gears... some UPS units put out a 120V AC square wave. This is fine for the switching power supplies in computers and much other electronics equipment (like our controllers), but this is really bad for AC motors.. i.e. pumps. They typically run very inefficiently and run hot when fed anything but power with a nice sinusoidal waveform. UPS runtime can really suffer too.

The best UPS systems put out a true sine wave, or a close approximation thereof. Some UPS put out what's called a stepped sine wave, which is not too bad. Then there is the modified square wave, which is nearly as bad as the worst, a standard square wave.

We really only have to be concerned with pumps/power-heads with 120VAC AC motors. Any pump that has a power supply should be fine though.

This is a diagram I created years ago for some client training...

 

[Orcrone]

Aarghhh!!!

Aarghhh!!!

Russ. Might this be the reason why my powerhead was very noisy & not moving much water when I tested the UPS?

Also you say: "We really only have to be concerned with pumps/power-heads with 120VAC AC motors. Any pump that has a power supply should be fine though." Does that mean that powerheads plugged directly into a wall outlet will have problems but if they're powered by an AC/DC transformer then they'll work well with a UPS outputting a square wave?

 

[RussM]

Yes, that might very well be why your powerhead ran poorly while on UPS power.

Powerheads which have a distinct power supply, "low-voltage" pumps, Vortechs, Tunzes, most controllable pumps, etc. in general will be fine on a UPS. Typical return pumps, skimmer pumps, basic powerheads (i.e. MaxiJets), etc. are the kinds that are not good on a cheap UPS.

 

[Orcrone]

So my two choices are to replace the powerheads or find a good quality UPS that outputs either a sine or stepped sine wave. How do you find that information?

 

[jrpark22000]

Google UPS and start looking for the most expensive UPS, this will give you big manufacturers. Then you can look at their product catalogue. The good companies will state their product's specs in a doc.

Hang in there, this can make your head swim trying to understand all the details.

 

[Orcrone]

Google UPS and start looking for the most expensive UPS, this will give you big manufacturers. Then you can look at their product catalogue. The good companies will state their product's specs in a doc.

Hang in there, this can make your head swim trying to understand all the details.

What specs do I look for? Do they state the type of output. For the cost of some of the more expensive ones I might as well start investigating whole house backup generators!!!!

Note: Head is fully submerged and swimming

 

[nixer]

And to throw another wrench in the gears... some UPS units put out a 120V AC square wave. This is fine for the switching power supplies in computers and much other electronics equipment (like our controllers), but this is really bad for AC motors.. i.e. pumps. They typically run very inefficiently and run hot when fed anything but power with a nice sinusoidal waveform. UPS runtime can really suffer too.

The best UPS systems put out a true sine wave, or a close approximation thereof. Some UPS put out what's called a stepped sine wave, which is not too bad. Then there is the modified square wave, which is nearly as bad as the worst, a standard square wave.

We really only have to be concerned with pumps/power-heads with 120VAC AC motors. Any pump that has a power supply should be fine though.

This is a diagram I created years ago for some client training...

interesting point, but then again you might walso want to bing up about generators that also do the same thing

 

[RussM]

interesting point, but then again you might walso want to bing up about generators that also do the same thing

Not really my area of knowledge.

 

[jrpark22000]

interesting point, but then again you might walso want to bing up about generators that also do the same thing

You lost me. An AC generator is an AC motor run by an external source. You are inducing power into a coil. How is this anything other than a sine wave?

Never heard mention of anything other. Do you have any references?


OrCrone, sorry to take this thread off topic. I just don't want readers to get confused.

 

[jrpark22000]

What specs do I look for? Do they state the type of output. For the cost of some of the more expensive ones I might as well start investigating whole house backup generators!!!!

Yes, better UPS will state output wave form. It should be stated in wording similar.

Note: Head is fully submerged and swimming

Swimming is normal for enginners in the field, it's why they only specialize in specific areas. Also why there are bachelor degree prorams. Still hang in there.



For pure simplicity, DC is the way out. You only need to worry about the intial AC/DC inversion while the batteries charge. Then you factor things like a good charger and battery type. Batteries are a whole new topic to make your head spin, but marine grade deep cycles if replaced every couple years do the trick, but they do have trade offs.


You can also just do some searching on here and ask around to members who have UPS and which brands/models they found to work to drive AC motors. Just get their long term results.

 

[RokleM]

interesting point, but then again you might walso want to bing up about generators that also do the same thing

UPS, generator, car inverter, they're all the same. They all have to take a power source and create a wave. They all suffer from the same downsides. Go cheap and your AC based pumps/powerheads will likely have an issue. Only safest bet is true sine wave devices like APC Smart UPS and Honda eco-generators.

 

[kurt_n]

Just as a data point, the Xantrex unit I mentioned above runs a "modified sine wave" output. I've used it to run my skimmer pump (Mag3), Koralias, and a couple different Marineland HOB filter units with no problems. And yeah... my Honda Eco generator runs things just fine too.