Blower Motor Buzzing on Inverter Power

I just connected my blower (
**Broken Link(s) Removed** ) to a new UPS (uninterruptible power supply ) in case we lose power &, while it runs ok when I unplug the unit to test it, the blower fan emits a slight "Buzz" when running off the UPS alone. As soon as I plug the UPS back in the buzz goes away. I'm assuming the blower motor is not being supplied enough power from the UPS but wonder if it's ok to run it like that, or will I end up blowing the blower motor??

Probably has enough power just the sine wave isn't as pure. Some motors don't like inverters. While it is buzzing ,try adding another item to the same outlet, such as a regular lamp or some christmas lights. Maybe that will smooth out the sine wave, but then it will draw more watts and shorten the length that it would work. Of course if you were into electronics, you could look at the wave on a scope and design a filter circuit to smooth it out. This link may help to understand whats going on. http://www.rocketroberts.com/techart/inverter.htm I guess what really would be good in a pure sine wave inverter, which of course probably cost big bucks.

This looks like it might be a better setup. The Series 700 Surefire Heater Sentry provides pure sine wave power suitable to operate any heating appliance within its ratings.

It's probably not a FULL SINE wave output, more than likely a "modified" Sine Wave output. It';s made for a Computer, A computer doesn't care, it takes the AC output and converts it down to DC (power supply) to run the computer, so it can pretty much be any output. That's why they are so much cheaper.

And the current draw of your blower, maybe not powerful enough. Look at the power rating of your blower. If it draws 200-300 watts, the UPS will only last about 2-3+ minutes (if that).

The GOOD FULL Sine wave outputs are much more expensive, but worth it so you don't hurt your equipment.

Motors and other AC equipment (refrigs, microwaves, etc...) can be damaged if run a long time on that type of output.
The may even run slower and get hotter.

It';s probably okay for short outages or until you get a generator online....

We just discussed this quite a few times...

Inverter for Homemade Battery Backup

Hmmmm, here's a question... what would it take to use a "cheap" inverter and make it into a pure one? Might it be a do it yourself job and be cheaper than buying a pure sine wave to begin with?

A lot of electronics and knowledge.

Probably cheaper to buy a good one in the long run.

As several have suggested the various "inverter, UPS, backup, etc." postings you can filter a non-sine wave inverter to make it a pure sine wave. To do so you need inductance, lots of it. The inductance can be a inductor choke or a transformer. That's what is normally inside the so called pure sine wave inverters. They are heavy. Basically a inductor choke or transformer similar to the weight of one inside a large microwave oven. It smooths out the high voltage spikes by converting them to heat in the transformer. That's the same thing your stoker motor has been doing when running on the non-sine wave inverter. At least until it overheated and went up in smoke.

Freddy, want to brew you own. Here's how, get two identical arc welder (AC buzz box) transformers. Hook them in series by connecting the welding voltage winding of one to the welding voltage winding of the other. Connect the inverter output to the primary (line voltage side) of one welding transformer and take the now pure sine wave output on the second transformer. Obviously don't try this unless you have a good understanding of electrical transformer principles and are smart enough to keep from getting electrocuted.

Yanche wrote:are smart enough to keep from getting electrocuted.

I'm that smart, but occasionally I allow the magic white smoke to escape from my projects.

Hmmmm.. TWO welders, huh? Full size buzz boxes? I'll keep my eye out for freebies!

Hahaha, I worked for Hobart food equipment many years ago; the boss' son ordered me to put the wrong capacitor in a slicer. We tested it out on the bench. I'm surprised David Copperfield didn't appear from the cloud of white smoke after the cap exploded.

How about just running it on DC?
Many motors have AC/DC ratings.
Just keep a bank of batteries at the ready with solar/wind/street power.

Motors that can run on AC or DC have brushes in them. Just like your power tools, drills, circular saws, etc. Those without electronic variable speed controls could be powered with ten 12v car batteries in series. Unfortunately, the boiler circulator motors, combustion fan or air circulation fans on coal equipment are not brush type motors. They are split phase motors. There are two motor windings, with a capacitor that changes the current phase with respect to each other. This is what produces the starting torque. The capacitor may or may not be removed from the circuit after the motor starts.

It's fairly easy to modify the Delco SI series of automotive alternators to produce 120 volts DC. In fact some in the construction trade would do this to operate their power tools.

The bottom line. If you need or want your coal appliance to operate without electric utility supplied power, you need to do some electrical engineering design. Any solution using new parts will not be cheap.

Yea, there is no real cheep and easy way to do it right.

I picked up this pure sine 1000 watt inverter when it was on sale for $250.

http://www.northerntool.com/shop/tools/product_20 ... _200347896