Generator-UPS-Pellet Stove

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BIGISLANDHIKERS

Feeling the Heat
Sep 12, 2007
316
I don't have the budget to spend $2000 on an inverter generator. I hear that the lower budget Chinese guys could zap sensitive equipment like pellet stoves. Would a UPS backup device hooked up in between the power produced by the gen and the pellet stove protect it? If so, how do I figure out what sized UPS is needed? I'm not looking at the UPS to operate the pellet stove when the power is out, just protect it from the generator.

Thanks
BIH
 
nope the ups will usually be very picky about the power it receives, just like the stove. many ups arent pure sine wave either.

one idea i have yet to try is...

a car battery charger plugged into the chinese generator, hooked to a battery which is hooked to a pure sine wave inverter which is hooked to the pellet stove.

almost sounds stupid now that i think about it and it would set you back at least $200 bucks not to mention the hassle of the science experient looking thing you will have created.

i have some high end ups's and on the chinese generator all they do is beep and click.

best thing to do is in a power outage just use the oil. the furnace doesnt seem to mind the dirty power.
 
Your question comes with two assumptions that may not be true. 1. Affordable inverters and generators produce power that is hazardous to electronics. 2. Pellet stove electronics are vulnerable to such electrical power sources. I have no idea what the facts are but I would want to learn the truth before assuming the worst. It may be that pellet stove electronics are off-the-shelf types of parts that have remained unchanged for a couple decades. If so, then their circuitry is not like the nano-circuitry of modern devices.
$2,000 for an inverter generator? What are you referring to? Harbor Freight sells an 800 Watt inverter for less than $100, 2,000 watt for $130. And also an 800 Watt generator for $100. A pellet stove uses less than 400 watts.
 
Excellent link thanks Dr. Faustus
 
arnash said:
A pellet stove uses less than 400 watts.
Mine on avg uses less than 100 watt's
I bought a pure sine wave UPS at Costco's for $99, last's almost 3 hr's, i have a cheapy $300 3500 watt generator and used it once in 5+ yr's, last summer had a microburst blast by my house and torn down tree's down on my street, ran my fridge and freezer's off it.
If the power ever goes out long enough i would hook the ups to the generator
 
Pluggin a UPS into a generator that is outputting a modified sine wave won't magically turn the signal into a nice clean sine wave and pass it on to the appliance, even if the UPS has a sine wave output. If you think about how a UPS works when plugged into a wall outlet you can see what I mean. When running on utility power, the UPS simply passes the utility power signal on through to the appliance, while also providing surge protection. The surge protection doesn't reshape the waveform, it just provides protection from surges. When the power goes out the UPS then begins to run off battery power, changing the DC voltage of the internal battery into a modified sine wave or a sine wave depending on the unit.

So, assuming you have a sine wave output UPS, you could count on the sine wave output when the unit is running on the battery, but when plugged in to a generator with a modified sine wave output with the generator running, the surge protected modified sine wave would be passed through to the appliance. Essentially, the generator is now the utility supplied power signal.

And yes, I would say that the motors and the control board in your pellet stove will run best with a clean sine wave signal as opposed to a modified signal. Oddly enough, computers seem to run alright for short periods on these modified sine wave signals output by the less expensive UPS models. This is probably because the computers electronics are all run on DC voltages. So a modified sine wave is simply converted to a flat DC voltage which takes away all the dirtiness in the AC signal. But the motors and electronics in your pellet stove run on AC (unless of course you have one of those models that has DC motors), so they are more sensitive to the AC signal.

I have read that the APC BackUps UPS units output a modified sine wave, but the more expensive APC SmartUps output a clean sine wave signal. Here's a great article that discusses the quality of power produced by various backup power devices which shows oscillioscope images of each.

http://www.jkovach.net/projects/powerquality/

As for the electrical consumption of pellet stoves see my other post here:

https://www.hearth.com/econtent/index.php/forums/viewthread/69904/
 
Keep using the search feature (I know I hate hearing that too). There is a very good post on here where a guy hooked up deep cycle bateryies to his APC and was getting extremely long use for his stove. I don't have the link handy and have to get going but it's here somewhere. Very good info.
 
BIGISLANDHIKERS said:
I don't have the budget to spend $2000 on an inverter generator. I hear that the lower budget Chinese guys could zap sensitive equipment like pellet stoves. Would a UPS backup device hooked up in between the power produced by the gen and the pellet stove protect it? If so, how do I figure out what sized UPS is needed? I'm not looking at the UPS to operate the pellet stove when the power is out, just protect it from the generator.

Thanks
BIH

Some generators have automatic voltage regulators (AVR) and claim their power is OK for sensitive electronics. You'll have to investigate if you're going to use one of these to make sure that the electronics is clean enough to run what you want to run with it. You'll often hear that you need a total harmonic distortion level of 5% or less for sensitive electronics. I have a generator with an AVR that I run my computer through an APC SmartUPS UPS unit, set on the low sensitivity setting, and the computers haven't been damaged. My manufacturer tells me that the THD is 15%. The voltage range is typically 115v to 120V, and the frequency is typically 58 to 62 hz.

There is a totally safe way around this. I have a $28, 300-watt inverter that I plug into a storage battery that produces very clean 120 volt power. When I had a 3000-watt cheapo dirty power generator, I charged one marine battery with my generator while I used the other one, and was able to power my computers throughout Hurricane Irene (5 days without electricity). If you have the storage batteries on hand, a cheap inverter could be your solution.

I should point out that this is not an inverter generator, but simply an inverter, which converts the 12-volt input from a storage battery into 120-volts that you can use to power low power items in your house. The following link will take you to a 900-watt inverter that is available from Sears for $65. THere are many other power levels available: http://www.sears.com/shc/s/p_10153_...9x00001a&ci_src=14110944&ci_sku=SPM2021099301
 
The honda/similar eu2000 are expensive, yes. They cost that much for a reason.

I'm building an alternative because I can't afford it either.

I figure a charge controller, 2 agm deep cycles, and a 2000 watt pure sine inverter should run about $500 or so depdning on how many amp hours you go for on the batteries. Throw in a solar panel or 2 and consider making a charger like above. HF just got the predator series in and there's a good coupon too.
http://www.harborfreight.com/Predat...iOiI2ODEyMCIsImlzIjoiOTkuOTkiLCJwcm9kdWN0X2lk
IjoiNzk2MiJ9
&utm_medium=email&utm_campaign=5211a&utm_source=1003
$99 with coupon 25550921

add the gm alt kit and you can have a re-charge unit for a couple bills. So, basically you would have the same thing as the eu2000 for half the price, and have the unique ability to go in silent mode at night. Charge with solar in the day, run the charger from dusk to sleep. sleep in peace and not have to leave your stuff outside for someone to steal, or worse-- know you have power.
 
Dr.Faustus said:
another thought... if you are handy, you can build your own generator with a lawn mower engine and a car alternator.

that will power a nice pure sine inverter easily which you can buy with the money you saved not buying a generator. heres a how-to

http://theepicenter.com/tow02077.html

I clicked through that link..there is some CRAZY stuff in there~
 
I use a Honda Eu2000 generator that sells for $1,000 new. It has an inverter and burns about 1 gal. of gas in 8-10 hours. I used it for 4 hours this year to power my 2006 Enviro Vista Flame 45,000 BTU pellet stove, 21.5 cu. ft. fridge, and my small microwave. The honda weighs 50lbs, and is the most reliable unit for the money. It also has a 3 year warranty the others have 1-2 year warranties. I also used it for 15 hours a week from april to nov. in my camper without a problem.
 
about 5 years ago i was looking for a cheap generator and found one at BIG LOTS for $150
i was suprised when i had to us it a day later power went out for 3 days ran my 25-pdvc plus 2 fans in the basement and the tv and dvd player with no issues and a few lights also.
the only issue i had was when i pluged the refrigerator. when it kicked on it made a power blink that sent the stove in to start up mode but other than that i was suprised what the little "cheap" generator would run it all.
im trying to build a battery back up for my 2 stoves (with very little money)
i cant believe that the generator puts out much of a clean sine wave but i have no way of testing it.
im looking for some thing to use as a ups till i get home from work or i wake up in the morning and can get the generator going.
 
I have a cheap Chinese inverter generator.....I cannot speak to longevity but I have plugged it into a UPS which my pellet stove is plugged into. The output of the generator was 121 volts at exactly 60 hertz...paid 400.
 
I read an interesting tip on Honda's website, and also spoke with someone who had some real world experience with it... They call it the generator UPS test... As mentioned above, battery backups (a.k.a. UPS - Uninterruptible Power Supplies) are sensitive to the AC input they receive, be it from the utility company or from a generator. For APC brand units the Powerchute software that you install on the PC actually lets you configure the trip point sensitivity that triggers the unit to switch between wall power and running on the battery. So, connecting the UPS to the output of a generator can give you some indication of how clean and stable the power is coming out of the generator. If the UPS keeps triggering and flip flopping between the generator input and the battery, or refuses to acknowledge the AC output of the generator and continuously runs on the battery, that is an indication that the power coming out of the generator is not clean or stable.

Here's a link to a page on the Honda website that describes the benefits of AVR (Automatic Voltage Regulation) Generators, and mentions the UPS test:

http://www.hondapowerequipment.com/products/generators/content.aspx?asset=gg_avr

There are several characteristics of a power signal that can result in electronic device and component failure. These include the smoothness of the curve (the closer to pure sine the better), the frequency of the signal (60 Hz is the norm for the U.S.), and fluctuations in amplitude. Inverter technology helps create a smooth sine wave curve, and voltage regulation method determines frequency and amplitude stability. Generators that use AVR methods can react to changing electrical loads as appliances turn on and off, avoiding power surges and brownouts that can damage electronics.

Oddly enough, computers don't seem to mind running on the modified sine wave (or stepped sine wave) output of the less expensive UPS units like the APC BackUps models. This is because the computers electronics mainly run on DC voltages. The computers main power supply takes the AC signal that it is fed and converts it to several DC voltages which in turn power the computers circuit boards and disk drives. Frequency and amplitude are the important factors here.

When powering appliances with motors that are using the AC signal directly a pure sine wave is preferred. Frequency and amplitude stability are also important to avoid damaging AC motors.

Even an inverter generator could potentially damage appliances if allowed to run out of gasoline, as the output signal may become erratic as the engine runs out of fuel.

I like the idea of going with a smaller generator with a pure sine wave output to keep things affordable without damaging my equipment, and powering only a few essential items like my pellet stove, a refrigerator and a microwave oven. This seems to give the best balance of cost, quality and how frequently you need to use a generator.
 
I have been through several hurricanes while living in Florida and have nearly a month of clocked generator time. I use the el-cheapo Brigs and Stratton 3250 watt job seen in the photo. I have powered $2000 LG fridge, $2000 Samsung TV with DIRECTV box, gas driers, 5000 BTU window A/C and various other circuit board based appliances. I have never toasted anything to day. Keep in mind that I did not run all this stuff at one time on a 3.2KW box.
 

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