Generator Use

I recall quite a discussion a while back about the use of our pellet stoves while running a generator for power.

We lucked out yesterday as an F4 tornado missed us by about 4 miles. Unfortunately, we're one of many still without electricity.

I have a decent sized portable generator we're using for lights and heat, etc.. It will handle the whole house if everything doesn't kick in or on at the same time. It was warm yesterday so very little call for heat last night. Tonight it's going to dip below 30 and stay cooler. This is typical burning temps for me but I have concerns about the "dirty" electricity.

A new fancy generator is not in the budget. Luckily we only need this one once a year or so and typically for short periods.

Can a UPS for the stove clean up the "dirty" electricity to protect the stove control board? Is the dirty juice just as bad for my LP furnace or refridgerator for that matter?

Let's discuss the options for all as Mother Nature has a way of making her presence known like this sometimes.

 

APC has told us that it will NOT correct a modified sine wave . i have an open frame 4k genny , but i also bought this inverter gen . http://supergenproducts.com/shop/refurbished-2000w-inverter-red/

 

I have a Honda 2500 watt generator that I bought during a major ice storm in '98. I have used it multiple times with my Harman, but not any extended periods like you might be facing. To date I haven't experienced any problems. Personally, if I had the choice of being warm or freezing, I'd run it and take my chances. But that's me. Good luck.

 

I ran the stove for a little while with the Kill-A-Watt meter on it. You could here the fans changing speeds as the line voltage varied up and down. Voltage was ranging from 114 to 120. I just shut it down.

I watched the voltage prior to starting the stove and it seemed pretty stable 118-120. I'm not sure if something else in the house was causing a load on the genny, thus regulating output? The stove only pulled about 140w after the igniter shut off and room fan kicked in. That's not much load on a 7250w generator. We only have a couple of lights on otherwise.

I found this and wonder if it would help?

http://www.amazon.com/Tripp-Lite-LC1200-Conditioner-Outlet/dp/B0000512LA

 

The same fluctuation occurs with the LP furnace blower until the gen is loaded up. Just showered so well pump kicked in and put a load on generator. Furnace blower fan was nice and stable.

I worry that voltage wandering plays hell with control boards and such.

 

As has been discussed here and on other forums, the main problem with some generator or inverter use on pellet stoves isn't as much the voltage drops (although I'm sure severe under or over will cause damage), but if the motors on the stove are subjected to modified sine output, they will start to hum, get hot, and eventually fail. If the generator produces fairly clean, sine wave output, the minor voltage changes shouldn't affect much more than the rpm of the motor. But if the output is modified sine (square) wave, THAT is the problem.

 

So it doesn't look like the Tripp Lite conditioner actually modifies the sine wave, just regulates voltage and protects from brown out and surges.

Ivanhoe has done it up nice. It's just not something most of us can or will invest in.

I've read elsewhere that modern furnaces and appliances aren't as subjective to this "dirty" power. With so many circuit boards I find that hard to believe.

Perhaps a smaller power inverter generator is the most economical answer. One could hook it up to a gas can and just run stove and fridge on it then run lights on regular genny.

Power restore estimated for Wednesday by 11:00pm. Let's hope they over deliver on this one. We took a drive yesterday to see some of the destruction. Man, it's horrible. One house that wasn't blown away was picked up from its foundation and moved about the width of the house and put back down! It was completely seperated but intact. Most others are just gone.

 

I have a UPS for my stove, basically just to give me time to set up the genny.

The AVR clicks on roughly 5-10 times per month meaning that my power drops below 100 or over 130 that many times per month.

My point is 114-120 is actually very good.

Most modern electronics can handle voltage from 100-240 without an issue. Take a look at your tv's power supply.

Now 240 volts for your pellet stove would not be recommended.

I would not worry about running anything on a descent newer generator....just don't let it run out of gas while in use

 

Without an answer from a manufacturer, or an oscilloscope we will never know the answer.
Imacman hits it 100% on the nose, it's not so much the voltage fluctuation as it is the actuall sine wave. A noisey or square (modified sine) will heat up and burn faster than the pellets in your stove.
I have a Generac 8500w portable that is not pure sine, but it runs my Englander just fine. and yes the motors do hum.
Best of luck with the power restore...

 

Woot!!!!! Power just came back on!!!! Hopefully on to stay.

 

Anyone who's considering a generator might want to check these out. Harbor Freight unit, but was a "Best Buy" by Consumer Reports....they rated the power "Quality" as Very Good. On sale right now for $600.
Buy a battery and it's electric start. 12 hr. run time @ 50% load. Not sure how you could go wrong. If the stove motors hum really badly,use it for the rest of the stuff in the house, or just return it:
http://www.harborfreight.com/engine...ng-watts-13-hp-420cc-gas-generator-68530.html

 

This is a page directly out of the current P-68 manual and is in all the new Owners Manuals.

Addendum
Minimizing Smoke During Loss of Power Using Battery Back-up
Harman® strongly recommends installing battery back-up to minimize entry of smoke into the
room in the event of power loss.
Your pellet/biomass burning appliance relies on a combustion blower to remove exhaust. A power failure
will cause the combustion blower to stop. This may lead to exhaust seeping into the room. Vertical rise
in the venting may provide natural draft. It is, however, no guarantee against leakage.
There are two Harman® approved battery back-up options for your appliance:
Uninterruptible Power Supply (UPS) UPS battery back-ups are available online or at computer and
office equipment stores. Your Harman® appliance with Rev E or later software available beginning in
November 2010 may be plugged directly into a Harman® approved UPS:
• The APC (American Power Conversion) model #BE750G and the TrippLite model
INTERNET750U are tested and approved. Other brands or models may not be compatible.
When power is lost, a fully charged UPS will power a safe, combustion blower only shut-down. Your
appliance will pulse the blower every few seconds to clear exhaust until the fire is out. NOTE: The UPS
provides safe shut-down only. It is not intended for continued operation.
Your appliance will recognize when power is restored. What happens depends on ESP temperature
and whether it is equipped with automatic ignition:
• In “Automatic” setting, units equipped with automatic ignition will respond to the set point
and ESP temperature and resume normal operation.
• In “Manual” setting or for units without automatic ignition:
• If the ESP is cool, the appliance will remain shut down.
• If the fire is out and the ESP is still warm, the feeder may restart. Since the fire is out, the
ESP temperature will not rise. The unit will then shut-down, and may flash a six-blink status
error. (See ESP error codes)
• If the fire is still burning, it will resume normal operation.
Contact your dealer if you have questions about UPS compatibility with your appliance.
Harman® Surefire 512H Battery Back-up The 512H connects to a 12 volt deep cycle battery that will
run your appliance for up to eight (8) hours. It includes a trickle charge feature that keeps your battery
charged when power is available. NOTE: If the power is out for longer than battery life, smoke
leakage may still occur unless your stove has been safely shut down.
CAUTION! Always keep appliance doors and hopper lid closed and latched during operation
and during power failures to minimize risk of smoke or burn-back.
CAUTION! Use only Harman® approved battery back-up devices. Other products may not
operate properly, can create unsafe conditions or damage your appliance

 

The Harman 512H battery back-up system is not puresinewave. I've looked into them and was almost as pricey as mine(in Canada). It's a 3 in 1 unit(inverter/transfer/charger). Here's a link;http://www.stovesentry.com/?p=surefireheater

 

I also think that the UPS systems they mention are a modified sine wave. Usually motors do not like these waves.....perhaps because Harman can communicate with the UPS and it only pulses the blower they are OK? Anyway if Harman says they will be good they will be good