Portable Generator

[plaindave]

I'll toss in my thoughts. I spent most of my career with the CAT organization and did a lot of work on the generation side of the business. It's not uncommon for a service guy to need to flash the field on a generator to get it putting out power. More common than most would like to admit. So that part of the problem doesn't surprise me. However you usually only need to do that after an extended storage period - I'm talking years here, not months. My guess is that you have a bad voltage regulator. A quick test and fix if the service guy is any good. Once fixed it should be good for a long time.

As for Generac's quality (or lack thereof), Generac is a price point builder and well known in the industry for being the low cost supplier. You don't get to low costs without giving up something. They build decent stuff, but it's always been a step or two behind the better competition. I have a Generac pressure washer. Great engine (their design) but the shaft size is a special shaft and the pump can only be replaced with a Generac pump. And the pump has a known problem of throwing shoes on the swash plate. It was cheap and lasted through the warranty. They figure on the average homeowner using it less than 5 hours per year. Same for the generators.

As for me - I got a Northern Tool generator, 5000W, Honda 9hp engine. Runs my well and everything else I need to get by in an outage.

 

[v8dave]

</font><font color="blue" class="small">( 7000 W should be OK for my house. I will not use the dryer and stove during power outage. I do not have A/C. The risk of having all appliances starting at the same time (the surge) is small.

One thing confuses me though. Honda has a 6000 W generator with 6500 W surge. How can Generac have a 7000 W generator with a 12500 W surge ? That's 5500 W more for surge (~78% more). )</font>

Possibly, the two manugfacturers are using the same words for different meanings.

In sizes above 5~10kw most generators have two power ratings. One for continuous and one for intermitent. The two ratings are generator temperature related, i.e., heat! At the steady power level (the lower number) the generator (not the gas/diesel power engine) can dissapate the waste heat without burning up. At the intermittent "surge" level the [electricity] generator can absorb the extra heat for a short time, but then it has to run for a longer time at a lower power level to get rid of the extra heat. Read the fine print, there will be a description of the time it can run at the higher power level along with the reduced capacity cool-down running time.

Another type of "surge" is the ability to start big HP electric motors. Single phase capacitor start motors take 3 to 5 times the KW power to start them as it takes to run them. This capacity is controlled by excess size of the generator and the rotating mass of the gas/diesel engine and the generator.

It looks like the Honda unit is talking about the continuous/intermittent and the Generac is talking about motor start.

Providing the Generac will run at all--it will likely start a well pump primarily because of its greater mass, the Honda probably won't, it is lighter weight. In fact Honda advertises its generators as light weight. Hondas may be more reliable, but the lighter mass won't start as big a motor.

 

[ns_in_tex]

This thread got me to wondering about my generator, so I proceeded to read the manual again. I can find no reference to using on a regular basis, or having to flash the fields. Do you know if this something that applies to 1800 rpm brushless generators or, are they immune to this situation?

 

[plaindave]

All of the stuff we did at CAT were 1800 or slower speed generators. All were brushless. This information isn't usually in the owners service manual, but the big shop manuals. I acutally think I learned it in a service school where they tell you all the things that aren't in the manuals.

 

[KiotiJohn]

The owner's manual for my OLD Onan 1800 RPM RV generator does say to operate the generator regularly at full load to exercise the generator head. They even made mention that simply starting it up with no load was not productive. John

 

[Soundguy]

</font><font color="blue" class="small">( All of the stuff we did at CAT were 1800 or slower speed )</font>

On our old tractors with gennies.. we have to polarize the field shoes if it sets for an extended amount of time ( years )..

Soundguy

 

[RalphVa]

You're getting a bunch of hoo-haa garbage. I'd take that generator back and ask for a refund. Sounds as though it's still on warrantee. Never heard of such a thing as lost magnetism.

I've an Isuzu electric start generator. I have it on my calendar to go out and run it for 15 minutes or so once a month. Sometimes miss a month.

Only complaint with it is it doesn't seem to start as readily as it should. Good thing it's electric start.

Ralph

 

[OhioGuy]

Hey Ralph,

Yea, I agree. At this point all you can do is pass the word and hope to cost them a few sales. It's been in the shop three weeks now, they haven't looked at it yet, I don't really care! I'm not particularly anxious to get it back. When I do, it will get regular testing. I'll be sure and post what they found when it gets fxed.

Curt

 

[Soundguy]

</font><font color="blue" class="small">( You're getting a bunch of hoo-haa garbage. ... Never heard of such a thing as lost magnetism )</font>

The whole principle behind most generators is based on magnetism... simple physics.

On lots of old generators, if you have the generator in a system that is not used for years.. or has new field shoes installed.. or the battery has been changed.. or even if you are changing the charge polarity, it is a common process to polarize the generator ( and regulator/cutout ) to set the initial charge polarity and residual field magnetism.

True this is an generator mounted on a car/tractor.. but i don't see why it might not also apply to a generator in a dedicated setup. Just depends on the field setup and control. Alternators were setup with different field control and didn't have near the maintenance issues as with the older gennies.

Soundguy

 

[OhioGuy]

Well, it's been 6 weeks in the shop, picked the wrong generator, picked the wrong service center. I called today and was told parts were on order, I asked what parts, after being put on hold the response was the paperwork couldn't be found but he knew it wasn't ready.

Tomorrow I'll call and ask to talk to the owner.

Genewreck, what a joke!

Curt