Inverter generator

[GeoHorn]

Good logic, skeets.

Why do people have sensitive electronics-failures using standard portable generators..??
Usually because they’ve bought too small a generator which struggles to maintain steady rpm..….Or…they fail to follow good operating practices that avoid subjecting the sensitive equp’t to fluctuations, such as:

• Turn the switches off or unplug before starting or stopping your genset.
• Do not run out of fuel and let your genset run dry.
• Buy a quality genset.
• Make sure your genset is the right size and not too small.
  • (Have some spinning reserve)

Another good operating process is to turn the generator-portion switch (circuit breaker) OFF before shutting down the engine. This prevents large fluctuations in the magnetic Field of the generator. (An occasional failure of portable generators to generate any electricity at-all…despite everything seemingly fine…. can be due to the loss of “polarity” of the armature/field in the generator itself.

Here’s the details of this particular rare failure-mode:
The actual generator within the package is comprised of a rotating armature spun inside an electromagnetic Field by the engine. When starting to spin, a “residual” magnetism of the pole-shoes of the Field initiates the magnetism of the Field. This “residual” is what maintains the “polarity” (N/S) magnetism essential to the process.
IF the residual magnetism is lost…for instance, if you let that generator sit for 5 years without running at all….the metal “shoes” which hold the Field windings…may lose their residual magnetism… and then will be unable to initiate any electromagnetic-force to begin the generating process.

Here’s the “fix”:
Take an ordinary electric drill-motor….(not a battery powered drill, but a genuine corded drill)… plug it into the receptacle of the portable generator while the portable is running….grab the drill-chuck with your hand and give it a sharp “spin” manually. (be certain you pulled/activated the trigger-switch on the drill when you do this.) The portable generator should immediately begin to produce AC current.
Why?
The small drill-motor is just another AC motor…and elect-motors and generators are merely mirror-images of each other. When you spin the drill motor you are being the engine and spinning the “generator” you’ve made of the little drill-motor….which sends current thru it’s power-cord directly into the portable-generator’s coils….. ”exciting” them… or “polarizing” them,….which then became self-sustaining.

Hint: Don’t try to hang-onto that little drill motor chuck very tightly…because it will immediately go to work when the portable generator instantly puts-out 120-VAC.

There’s another, ever RARER failure-mode that can occur with portable generators. The voltage output may disappear and the little drill-motor “fix” doesn’t work. Inside the “control-panel” of the portable generator you may find a small capacitor/condenser…. a little metal ”can” or cylinder…might be about the size of a D-cell flashlight battery…. and it may have failed. (This sort of thing might already be familiar to you when your home central air cond unit ….which has a larger capacitor the size of a shaving-cream-can….fan-motor/compressor-motor fails to start/run.)
The typical portable generator has a capacitor rated at about 25 uf (micro-farads) … and (less-importantly ) which can operate at up to 300+ volts. If that capacitor/condenser fails the portable generator may fail to excite/initiate….until you replace it with a good one.
This occurred to me on a camping-trip thru Jackson Hole. We were camping on BLM land and needed our generator as it was HOT and we wanted air-conditioning. No one in Jackson Hole had any idea what I was wanting…. until I found there was a water-well drilling service in town.
I pulled up to their maintenance shop and asked if they had any run/start pump-motor capacitors. Yep…they had a large selection…and they wanted an outrageous $60 for one that was ..close but not exactly correctly-rated…. theirs was 40 uf… but I bought it and installed it and the little generator made 128 volts for the rest fo that trip.
When I was able to get to a Whole Foods (Amazon Drop-Box) I ordered/received ($11) the correctly-rated 20-25uf capacitor…which fixed the little generator …puts out exactly 120 volts again. That was 4 years ago and still running fine.

GEDIZA 25 uF 25 MFD ±5% 370/440V Run Round Capacitor for HEVAC, A/C for Condenser Straight Cool or AC Motor and Fan Starting or Heat Pump A/C, Pool Pumps. Model CBB65. Guaranteed to Last 5 Years: Amazon.com: Industrial & Scientific

GEDIZA 25 uF 25 MFD ±5% 370/440V Run Round Capacitor for HEVAC, A/C for Condenser Straight Cool or AC Motor and Fan Starting or Heat Pump A/C, Pool Pumps. Model CBB65. Guaranteed to Last 5 Years: Amazon.com: Industrial & Scientific

www.amazon.com

 

[lugbolt]

yeah on a lot of non-inverter gens the frequency varies with RPM. So it might be 65hz when you are running no load but when you turn the microwave on, it might drop to 45hz when the engine rpm drops because of the load

inverters try to maintain hz and rpm as best possible, and IMO much better in most higher end gens. Honda and Yamaha come to mind here. Also the "governor" is electronic, and responds to load changes MUCH better. On my yamaha, the RPM will change about 25 rpm at the most so long as the load doesn't exceed about 2000w. My older 5500? 200-1500 RPM variance with load changes. And of course the frequency changes drastically as well with that much RPM variance.

the frequency change can play with sensitive equipment. TV's sometimes don't like it. Some are more sensitive than others I'm told, but I can't say which ones. I work next door to an electronics store and something I learned today about TV's. One major brand will have two different models, but they may be the same models. The mass-market version will have less expensive and mostly poorer quality electronics than the non mass-market version. Control boards and chips are the big key takeaway I'm told. Of the stuff they sell next door, it's very rare to have a failed TV. But the ones from the big box stores? LOL. A user of this forum is a tv fixer, and he can tell you all about that stuff

Remember that when it comes to buying on price....same goes for germinators I mean generators. A box store inverter is NOT the same quality as a Honda that you can buy at a Honda dealer but it might have a Honda engine on it, right?

inverters are simpler in how the generator itself is set up. The generator is generally smaller. Some of the smaller units, the generator is built into the flywheel/stator on the engine making for a really small, really compact and lightweight unit. The downside is that when (or if) anything goes wrong with the control board assembly it can cost more to replace the board than a whole new gen costs. I did an EF3000iseb once, the board was bad, new board and harness was $1700 and an entire generator at that time was $1600. Needless to say the owner replaced the whole thing, and I bought the old one from him for $50. I took the board apart best I could but it is mostly potted in epoxy and impossible to repair.