UPS FOR HARMAN

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kyburnr

New Member
Hearth Supporter
Sep 6, 2008
147
Kentucky
Looking for LOW cost UPS battery back-up for XXV to cover short power outages (30-60 mins) To use when not home and stove running on manual (so the igniter wont be needed) Looking for a computer type...not marine battery. Anybody using something that fits the bill? Does it even exist?
 
KYBURNER,

whatever one you end up getting, make sure it is a PURE sine wave type.....the modified sine wave types don't work well on the motors we have in our stoves.....possible overheating issues, if I remember correctly.

Do a search...it's been discuss quite a bit on here.
 
Macman is correct.
You will need a sine wave ups backup.
I have a harman accentra and tried a modified sine wave backup, the motors almost stopped and made humming noise.
I am looking at a Refurbished unit(much cheaper)
Here is a site that has APC units (APC website has a link to this site)
Look for the smart ups units, they are sine wave.
http://www.buyupsonline.com/
I have not purchased one yet, but looking.
 
I can vouch for APC. They make very good UPS for the dollar. I have tried cheaper ones but returned them and bought pricier APC. The quality is worth it. Plus they have a battery return and recycle program and a trade-in program if you ever want to upgrade your UPS.

But size it carefully. They have some different configuration tools on the sight. This one may work, but look around at the other parts of the site too: http://www.apc.com/tools/ups_selector/index.cfm
I am still dithering over wood vs. pellet, so I do not know the power requirements for a pellet stove.

But I use APC for both my PC's and my 90 gal aquarium. They work like a charm.
 
I just purchased a CyberPower UPS for my Harman Advance. I figured that the cost of the UPS was well worth the piece of mind for the protection. Your recommending as others have, a pure sine wave. I am not sure I have seen it stated that way on the UPS sites when I was scouting around. I ended up purchasing one that has "AVR" automatic voltage regulated. Is this the same thing as a "pure" sine wave? I noticed some siad "simulated" sine wave.
 
Codebum....Have you tested it out to see how long it lasts?
 
Hi kyburnr,

T.G.I.F.

Actually I just received yesterday so I have not had a chance to hook it up yet. However, my reason for purchase may be slightly different tha yours. I was not looking for extended backup time. I just wanted something to handle the voltage fluctuations and very short interuptions that I sometimes have. I have been in my house for 21 years and have only lost power for a couples hours once. The electric does goes off momentarily though on occasion though. Just enough that all the clocks need reset. I figured since I paid $3500 for my stove, $110 for protection against suges and short outages was a good investment.

Also, in south-central PA, I don't usually have to deal with the constant bitter temps that some of the folks futher noth do. Now that I said all that, I have probably jinxed myself.

My recommendation would be make sure you get one with wattage that you will need. They come with many outlets. You'll need to consider any other appliances that you may plug into it as well.
 
I have the Cyber Power CP850AVRLCD UPS ((broken link removed to http://www.cyberpowersystems.com/products/ups-systems/browse-by-category/intelligent-lcd-ups/CP850AVRLCD.html)). It is an intelligent UPS and I will be using it with my Pellet stove as well as with the mini backup generator that I just purchased (http://www.amazon.com/gp/product/B000P9UOAC). This will allow me to run on battery for the short electric outages that we have from time to time (Based on the LCD it will run for @ 70 Minutes once the stove is started). For extended outages I will plug the UPS into the mini generator to cleanup the power and plug my entertainment system into the UPS. I will have heat and entertainment for extended outages. What more can you ask for @ $200 ;)
 
Teddy,

That sounds good. For my situation I bought the CP900AVR.

kyburnr: Be carefull when you look at the ratings. Many claim a specific amount of backup time but when you look at the specs, at half load the time is significantly reduced. Full load is barely anything. Initially I thought I would get something that could hold me for hours, then after researching on the web, I found that for the same same cost I do as Teddy mentions...get a small generator and a ups.
 
My stove is hooked up to a APC XS1300VA- 780 watts. - so far no problems at all.
Power went out a few times last winter and it ran the stove just fine.

Waveform Type- Stepped approximation to a sinewave
 
The sine wave thing gets a little confusing .....pure sine wave & simulated sine wave & modified sine wave.

I guess the pure and simulated or OK and the modified is the one that does not work well with fan motors?
 
kyburnr said:
The sine wave thing gets a little confusing .....pure sine wave & simulated sine wave & modified sine wave.

I guess the pure and simulated or OK and the modified is the one that does not work well with fan motors?
There are really only two - pure sine waves and modified sine waves (really modified square waves). Modified waveforms can be pure squares with sharp edges or filtered to produce more rounded, less spiky waves but they are never really sine waves. Lots of stuff work fine with modified sine waves, some things don't. A modified sine wave generator is a lot less expensive to build than a pure sine wave one so it makes sense to use one when possible. Some things like some motors don't like modified sine waves (other things like light dimmers, digital clocks, etc. generally don't like modified sine waves either). But, not all motors have a problem with them so it's a crapshoot. They'll all work fine with a pure sine wave but only some will work fine with a modified wave. If you were buying your UPS locally and could bring it back if it doesn't work with your stove you could save some bucks by trying a modified sine wave box and if it works keep it, if not trade up to a pure sine wave.
 
Thanks for the information on the sine waves. I see now that the one I bought says "Simulated Sine wave". At least now I know what that means. I am going to try it though since my outages tend to be very short.
 
codebum said:
Thanks for the information on the sine waves. I see now that the one I bought says "Simulated Sine wave". At least now I know what that means. I am going to try it though since my outages tend to be very short.
Usually when motors have problems with modified sine waveforms it's on startup/load scenarios. In yours where it's already running at speed and you're just looking for it to keep going for a bit, you may be just fine. Some folks here have found modified sine waveform UPSes that worked with their particular stove so it's just a case of seeing if it works.
 
I guess that is all I can do. If it doesn't work then I'll use mine either for something else or use it on surge protection only until I can fork out the money for a pure sine wave unit.

kburnr:
I spent some time at CyberPower's site, APC's site and some search results on simulated sine wave vs. pure. Wow, there sure is a lot conflicting information out there. I guess as someone who didn't know better when I bought mine, I would recommend if you can afford the pure sine wave unit, get it. Then you won't be doubt.

I read everything from newer electronics can handle a simulated wave, to it will damage the circuits. Others said that the circuits would just think there is no power and shut down. Some said older appliances and motors using bridged diodes and rectifiers could handle it and others might not or might hum and over heat. Most of the readings say check with with you manual or manufacturer to find out if your appliance can handle the simulated sine wave. Yeah, I dont see anything in my stove's manual or specs. Something tells me if I call Harman they won't know either.
 
Thanks for the info

Diggerjim ...... Is simulated more like Pure or Modified?
 
kyburnr said:
Thanks for the info

Diggerjim ...... Is simulated more like Pure or Modified?
Simulated is just another word for modified. It has no real electrical meaning. There are waveforms that are modified by electronic filters between the square wave and the pure sine wave that get the "modified" label. The two modifications are either rounding off the "corners" of the square wave or flattening the 0 point. Unless you can look at the waveform or they include a picture of it, you can't tell whether the modified (or simulated) wave is more square or more sine like.

A sine wave is a curve that rises over time to maximum voltage, drops over time to 0 and keeps dropping to maximum negative voltage and then begins rising again. Even though it all happens very fast (60 times/sec in the U.S.), it's a real progression of building and falling voltage. A DC waveform is square - it goes straight up, stays there for a bit and straight back to 0. When shoved through an inverter to make that DC into AC, the wave is replicated on the negative side so it's straight up, a bit of time at maximum voltage, straight down to maximum negative voltage where it sits for a bit before going back up. The two problems a lot of devices have with this is that the voltage is either minimum or nearly instantly maximum - there's no buildup over time, as a result it stays at voltage longer than a true AC sinewave. The other problem is that it goes straight from max positive to max negative without spending any time at 0.

Lots of things can't handle the longer max pos/neg voltage of a square wave so the "edges" or "corners" of the square are modified by rounding off with filters. This makes it seem like it's spending less time at max pos/neg voltage. Other things (mostly variable speed things like motors) need the 0 voltage point to set timers (using SCRs or Triacs) in the circuit. The problem with square waves is that they spend no time at 0 so the SCRs/Triacs can't sense the 0 point so the timer doesn't start. That's why the motors don't start - the circuitry can't sense 0 so it doesn't start it's "allow voltage" mode. Some circuits will allow the motor to run (like a variable speed drill - it's either on or off but won't vary its speed 'cause the circuit can't sense the 0) but others won't even allow full voltage to pass without the 0 point being sensed. So square waves are modified again to have a flat spot at 0 where it spends a bit of time there in an attempt to force the circuit into seeing the 0 point. Unfortunately, it's the change over time that the circuit is looking for - it senses the slope of the curve and there isn't any slope to the on or off nature of a modified sine wave. So some devices may sense the 0 resting point of the flat spot or may not...

Electronic devices don't have problems with the on/off nature of the power (and are often just re-transforming the waveforms themselves before using them in the device --- DC to AC in the UPS and back to DC in the device :-) ) which is why they work okay with the UPS power. The real problem is that you can fairly easily cut off the corners of the square, but it's really hard to get the sloped line of change in voltage over time through the 0 point without actually being a pure sine wave so there really isn't a modified wave that has a flat spot at 0 that looks almost like the sloping change thru 0 that the pure sine wave has. That's why a DC source with a pure sine wave is more expensive than one with either a square or modified waveform.

Now you know more about power waveforms than almost any sales guy selling you a UPS.
 
More Power

I have a 24 volt apc ups hooked up to my Harman p68. I got rid of the small 24 volt 5-7 amp hour battery and use my two 115 amp hour trolling motor batteries wired in series to get a 24 volt system with it. Will run my stove for a long time if the power goes out, perhaps 20 hours in manual mode.
 
I use an APC Smart UPS 1500 for my stove. I get about 4-5 hours of power from it.

It's small, about the size of a stereo receiver.
 
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