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Electronics/Inverter vs. non-inverter generator


Davey1000 wrote at 2009-09-25 23:03:26
Re a previous post about stand-alone generators and whether they need surge arrestors.  A lot depends on the generator.  Some gensets produce huge over-voltage spikes when the load is disconnected.  (in laymans terms it is a bit like water-hammer in a pipe).  Two wrecked gensets that I was asked to “look at” have gone this way.  One set was an old and very rare  3KW Nissan diesel with a 6HP engine.  The machine was powering an automatic electric kettle which switched itself off when it boiled.  The Nissan has not worked since.  A similar failure occurred with a Honda EM4500X.  In this case the genset was driving a submersible water pump which had a float switch.  When the water was gone the pump switched itself off and once again the generator has failed.  I have mended quite a few gensets in my time and would  say that surging or spiking - call it what you wish - is the #1 cause of failure even with machines with a good pedigree,  Newage-Markon for example.  One rather novel design by

Haverhill Generators seems to be immune from this problem however as it has a large capacitor across the output terminals.  With the Haverhill, the whole of the generators output is put through a bridge rectifier.  The DC output of the rectifier excites the field winding whilst the AC feeds the load and capacitor.

   In general it is a good idea to always have some resistive load across small generators, a 60 watt bulb will do.  The bulb is a great help when variable speed power tools are being used.  Such devices cause constant trains of voltage spikes with sufficient energy to burn-out the smaller Voltage Dependent Resistors.

         As to inverter generators.  These seem to die like flies, in fact when used for business use the guarantee is often reduced to 90 days.  

poo wrote at 2009-10-05 23:13:04
I'm sorry for Dan's answer, he is a stoner (my opinion.) My computer would not even run on a regular generator. My TV worked but it was scary... it kept dimming and then would brighten, depending on if the generator was powering something else. And what's Dan mean by "best power"? And plastic in bearing is referred to the sleeve not the bearings. I've seen ball bearings in plastic sleeve's too.

PB wrote at 2009-11-18 17:18:44
While it is true that many electronic appliances these days are virtually immune to the various fluctuations of electrical properties, there are several things out there that are still very sensitive to fluctuations in sine wave, and/or drops and surges in voltage, namely refrigerators and such.  Unfortunately, these are the appliances that  people are most interested in backing up during a power outage.  An inconsistent sine wave can destroy a compressor with no problem, as can a drop in voltage--the latter being a more common phenomena.  There are plenty of people out there who have had this happen to them, and what is worse, it has happened to some of the most expensive frig/freezer appliances you can buy.  However, the quality of the generator itself can make a difference with this problem.  However, the difference will be minimal, simply because whenever the generator is called on to power up an inductance load, such as what a large percentage of electric motors induce, your engine rpm is bound to drop, no matter how quickly even a governed throttle can respond.  To test this, just connect a voltmeter or even an O-scope to the receptacle of any portable generator or otherwise, and take note of the fluctuations when you start up any inductance load, such as a window A/C or frig, or even a small appliance with an electric motor. If you care to compare an inverter type with the same instrumentation, you will notice a considerably more consistent set of readings.  Without getting too complicated, this is because the inverter has electronics that act to for any irregularity in current.  With this in view, Dan asks a perfectly valid question.  Dan, whatever device you choose, make sure the engine is giving you at least 2HP per 1KW.  Beware of anything that claims that you can get more wattage with a smaller engine--it is a marketing ploy.  I promise you.  The more conservative the ratings, the better off you'll be.  Go to someone who knows the business, even if you pay a little more.  

stekib wrote at 2009-12-18 16:34:49
My experience with small 5-10 KW gas generators has shown me that these units don't have clean enough power to allow my APC UPS battery backup devices to even come online. I finally purchased a Cummins Onan inverter generator that worked with my UPS units. It also had clean enough power to operate my televisions with no problem. These units do cost more than the typical generators purchased at Home Depot and Lowes.

Tom W wrote at 2010-01-12 00:32:49
There's another HUGE advantage to the new inverter generators: They're usually a LOT quieter at low load levels.

I regularly attend outdoor events where there's no power supplied, and we rely on generators for the PA system and lighting. My standard 3500 watt generator is loud enough I need to hide it around a corner. The Honda inverters are so quiet that you can stand right next to them and still have a conversation. I'm thinking of ditching my 3500 watt noisemaker for one of those 2000 watt inverters for the noise factor alone.

So no, you don't need to pay extra for an inverter - a standard generator will do fine, but if you want to be able to run this thing just about anywhere and any time, the inverters sure are nice to have.

marcus wrote at 2010-12-26 20:52:26
I agree with dan, FYI Generac sells the XP series of generators that put out utility grade power, and the XP8000E gets an oil change every 200 hours vs. conventional generators every 24 hours during non interupted use. The Alternator on the generator i am talking about is also as big as a BBQ grill propane tank.

Fred wrote at 2011-07-30 23:33:58
We had a new furnace installed and the shop specifically said to be sure to get an inverter generator for backup because the furnace is computer controlled. Here is another "expert" opinion on the topic. So who do we believe.

When choosing a portable generator, you’ll obviously have to choose a model capable of handling the power consumption of all of the appliances that you plan to operate (plus any additional power that certain types of appliances need to start) but did you know that the type of appliances you plan to operate will also be a factor in your decision? A standard generator is suitable for operating most types of appliances such as a refrigerator or a table saw, but it can cause more sensitive electronic equipment such as computers and stereo equipment to operate improperly or even shut down. Digital equipment requires clean power that is consistent and has a stable signal in order to operate properly and safely. If you plan to operate digital equipment as well as non-digital equipment then the best approach will be to choose an inverter generator that is capable of powering all of the appliances that you plan to operate. Your alternative would be to choose a standard portable generator for your non-digital equipment and an inverter generator for your digital equipment.

Source: Marketing Group Content Development Team  

Mathew wrote at 2012-04-01 23:46:37
This answer is right on.   This is from one expert to another.  I am a BS EE with a background in power.

walter wrote at 2013-03-07 00:00:37
Electronics in led tv's, plasma's and computers, fridge electronics need power that does not have a high harmonic distortion. " generators have a high THD ( total harmonic distortion) this causes electronics to go bad due to the constant rise and fall of voltage under load  


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