Any HVAC Specific UPS (Uninterruptible Power Supply) Options?

Steamback

If someone searches UPS (uninterruptible power supply) there are a million hits for cheap and affordable "computer oriented" UPS systems which simply offer plugs for consumer 120v devices. I know I could always use one of these to achieve whatever backup power goals I need for an HVAC system, but admit it would look unprofessional with a line cord connection to the UPS, and I doubt any good code official will like it either.

Are there any companies making similar UPS systems but with a more industrial/HVAC flavor? Like something I'd hardwire to a handful of high efficiency circulators using armored cable? I'm talking pretty small capacity, like possibly even running one or two high efficiency circulators for just 6 or so hours to make sure a wood boiler doesn't blow off mid-burn.

Anyway, I have no idea where to look for such a device. Any ideas?

Jamie Hall

I'd probably go looking for a combination of storage batteries and a quality invertor which could be hard wired. Northern Tool, Tractor Supply...

NY_Rob

ECM circulators?
Look for a Pure Sine Wave UPS or inverter, ECM circulators don't like standard inexpensive "stepped square wave" UPS/inverter.

6hrs off a UPS is a long time, doubt you'll get that, 3hrs... maybe.

Shalom

Are there any manufacturers of UPSen with 24vac output? Or even input?

pecmsg

How long does it have to last?

BobC

Cutom units are available but they cost an arm and a leg. It would be a lot easier to just use a regular 120v UPS and a 24 v transformer.

Bob

SuperJ

If you've got an efficient pumping setup 6hrs should be doable. It's possible to get into low double digit wattage's with proper a setup.

Steamback

Thanks for all the comments.

I did a little more digging based on everyone's feedback and think maybe something like this is interesting. At least for the boiler example.

https://www.tripplite.com/700w-powerverter-aps-12vdc-120v-inverter-charger-auto-transfer-switching-1-outlet~APS700HF

The line cord stinks but for the price it seems good. Any battery size can be used. I'm pleasantly surprised it has auto-transfer.

Anyone know a similar product (for the price) that can be hardwired to load.

Or better yet something affordable that also can do everything the above does but also charge a 48v battery bank? That's what I'm looking for next...just for giggles I guess to price out an extended runtime backup scenario for a bunch of circulators. So far something like this is a contender, is also surprisingly affordable, and is available with 48v. But I sure do wish it were made in America.

https://youtu.be/NKN4ZfEC4OU

PS - definitely low watt circulators. I think the Grundfos Alpha is worth every penny in most applications. Just having the flow rate and wattage display is worth the extra cost.

NY_Rob

^ Look at the specs for the Tripplite... output is "PWM Sine wave", same as "stepped sine wave".
https://www.altestore.com/blog/2015/10/pure-sine-wave-vs-modified-sine-wave-whats-the-difference/

If you have ecm pumps, you need "pure sine wave" output or it will fry the pumps. I ran my Grundfos Alpha on a sub $100 "APC Back Office" UPS during the summer... it buzzed like it was ready to explode, then I brought a "pure sine wave" UPS home from work to try... the pump ran as normal, nice and quiet no buzzing.

I connected my scope to the cheap $100 "APC Back Office" UPS... no wonder it almost blew up my Alpha pump... that hardly even resembles anything even close to a sine wave!

"Stepped Sine Wave Output"...

ratio

Leonard

Think that's called "modified" sine wave. My APC brand computer UPS outputs something like that , ~ 23% THD (that's high) , 1000 VA (watts). When I ran my soldering gun on it I could hear the buzzing of the harmonics. Computers don't care, they use switching power supplies that rectify all that scrap down to DC then use it. In transformers and motors only the base 60hz is used , the harmonics cause extra heating of windings , laminations and noise.

I wouldn't use UPS with built in gell cells, they over charge the cells and they die in a few years. Also they are geared to only ~ 15 minutes full lload (when bats are NEW). Plus not much heat sink on the output transistors.

In RV's common to use a charger/inverter and large bat bank for power, Much better solution. True Sine wave is available.

How many watts is your load? Easiest solution might be just a generator and auto transfer switch dedicated to that load. UPS can stay up for 6 hours just need big enough bat or multiple bats. Guy I know uses gold cart bats instead of running a gen overnight at home. Problem is bats age, eventually have to be replaced $$$, maybe 10+years. Old Onan Gens are very reliable, nat-gas/propane kit makes gasoline ethanol issues go away.

Might post the question here on "Smok Stak" website. They have a generator section. The real gen tech experts are in the Onan subforum. And some have Large bat backed up UPS.
https://www.smokstak.com/forum/forumdisplay.php?f=1

Leonard

Seem to remember some of the Stak guys having an "outback" brand inverter.

MikeG

What do you look for in the specs that lets you know it is pure clean sine wave. I have a mod con boiler and I'm not sure i want to run it on a generator. The back up part is not an issue. If I need to run it on a gen I could plug something into the gen then the boiler into an UPS. What is a good route to go on this and what type of equipment. Ideally something that is ready when needed but no batteries if possible. My gen is not automatic.

Jamie Hall

I might point out that not all generators are pure sine wave, either -- some of the smaller lighter more efficient etc. ones are invertor types, and aren't much better than that one which @NY_Rob put up the 'scope of!

However, somewhere in the specifications it will say pure sine wave, or words to that effect. It will also be more expensive, per watt, than most...

And @MikeG -- why not run a mod/con on a generator? If you have one which produces decently clean power you should be fine. Most of the bigger ones do... (see comment above, though, about generators). If you just need to clean the power up, though, you can run it through a power conditioner such as is used for ultra high fidelity sound systems. They aren't cheap, but they do the job.

JUGHNE

Dumb question time: would a 1:1 isolation transformer help?
Or if you put a choppy sine wave in would you get a choppy wave out? The scope would tell you.

NY_Rob

^ I'll scope a AC transformer running off my crappy UPS next time I have the scope out. It won't be 1:1 though, I only have a couple of 24vac transformers sitting around.

My gut tells me you would need more than a transformer to turn that mess into a sine wave, because if that's all it took... the UPS manufactures would do that for the extra $2 it would cost them.

MikeG

Jamie,
I have not had to run my boiler on a generator. I was just trying to be prepared if I did. I hear that the newer boiler and furnaces with more and more electronics, boards etc may not like the power from a regular generator. Maybe it will be fine. If I had something that didn't need batteries to keep charged like a UPS that would be best. Originally I though about just running it through a UPS we use on our computers but I guess those don't really do anything to clean up the power. Historically most of our power outages have been for 24 HRs or less and more happen in the summer. My boiler heats the indirect but I'm just looking at the what if factor. Thanks

Jamie Hall

Two thoughts -- @MikeG -- it depends on the generator. They come in two broad flavours, and a host of variations within them. The newer, smaller invertor sometimes are good -- they will say that they are safe for sensitive electronics or something of the sort. Really big ones -- which run at a constant 3600 or 1800 rpm -- are usually very good. However, there are a number of inexpensive small invertor generators which aren't. You just have to look at the unit in question. My old 16KW Generac is pretty good (there's some third harmonic, but it's not bad), for instance. But it's also old (like 20 years) and heavy and guzzles gas...

And for @NY_Rob - you are so right. A transformer won't help much (it will heat up nicely, though). You need to have more steps in the chopping -- and a couple of nice big capacitors and inductors -- if you are going to go the invertor route. 'T'ain't cheap...

pecmsg

The best generators are the new inverter generators ( Honda E-2000 and such ) that generate DC then run it thru a quality inverter (inverter is part of the generator. Not an add on unit ) which makes very stable and true 60 cycle sine waves regardless of the speed of the motor. That is how they are able to power small loads while idling and still output clean 60 cycle AC.

Jamie Hall

pecmsg said:

The best generators are the new inverter generators ( Honda E-2000 and such ) that generate DC then run it thru a quality inverter (inverter is part of the generator. Not an add on unit ) which makes very stable and true 60 cycle sine waves regardless of the speed of the motor. That is how they are able to power small loads while idling and still output clean 60 cycle AC.

Agreed. For smaller loads, those are excellent units. Quiet, economical... the works. There are other makes in the same class as well.

If that's all the power needed (they don't go much over 3 KW) they are definitely the way to go. If you need more muscle... not so much.

Leonard

Have not heard of inverter gens making non-sine wave output ,but I suppose some cheapie china gens might.

Pretty sure Honda gens make clean sine waves. The couple Onan gens that use inverters make clean sine waves.

Onan gens make pretty clean sine wave output, whether inverter or not.

Some cheap box store gens make pretty sloppy sine waves with high THD (total harmonic distorsion) About the sameTHD as the scrappy pulsed sine waves. Moral of the story don;'t buy cheap junk gens.