High altitude generator/inverter operation

Bacchus · 07-23-2017, 09:52 AM

I purchased a Champion 3500w dual fuel generator/inverter to run my 1350btu air conditioning on my Shamrock 21ss and here is what I have found. It will not work at a moderate altitude of 4000ft! It works fine at 2800ft but not at 4000ft. Not only will it now run the air conditioner but the inverter does not produce a “clean” sine wave making it impossible to operate a computer while the generator is running, here again it runs fine at 2800ft. In closer reading of the owners manual it states that the 3500w rating is at sea lever and that it looses 3.5% power for every 1000ft in elevation which means at 4000ft it looses 14% for an output of only 3010w which is not enough to start the air conditioner and for some reason also does not produce a clean sine wave. According to the owners manual it is possible to get a high altitude carburetor main jet, however, if you install the high altitude jet then you can’t operate the generator below 3500ft (if I am reading the manual correctly) which means if I want to run it at home to test it I need to reinstall the old jet and when I go back to the mountains I again must install the high altitude jet. Has anyone else had this or similar problems and if so is there another fix?

HONDAMAN174 · 07-23-2017, 10:11 AM

Are you running gas or propane at 4000 ft?

Bacchus · 07-23-2017, 10:21 AM

Running gas.

Skyliner · 07-23-2017, 10:34 AM

Altitude should not affect the purity of the output alternating current. How do you know that the power is not a clean sine wave? Did you put the generator on an oscilloscope to look at the output sinewave? You are probably having voltage issues with the generator's engine not running as it should.

The loss of 3% per 1000 feet altitude is under ideal conditions meaning the carb is jetted for that altitude. If you don't have the proper air/fuel mixture at different altitudes then the 3% loss will be worse since hte engine isn't anywhere near running where it should be (stochiometric is 14.2:1 air/fuel ratio).

Running a high altitude jet in a generator is not a problem, it is a fix. One day we'll get fuel injected generators and won't have to worry about rejetting for altitudes. Rejetting a carb is a fact of life-get used to it.

Running a high altitude jet at low altitudes may cause your engine to run too lean and damage it. if you have an adjustable choke, slightly choking the engine at lower altitudes with a high altitude jet may help.

I suspect you have something else going on, I suspect head space and timing issue.

rsdata · 07-23-2017, 10:57 AM

Quote:

3010w which is not enough to start the air conditioner

add a hard start capacitor to avoid this problem
search threads here to find additional hard start cap info

Your computer should still run on NON-SINE waves, as the brick inline with your power supply turns the AC back into DC anyway...

have run many laptops over the years on non-sine wave inverters just fine

Bacchus · 07-23-2017, 11:00 AM

The reason I suspect the sine wave is not good is because a computer timing is keyed on the 60 cycle sine wave, if you do not have consistent sine wave then the timing is not correct which would cause the curser to jump all over the place. Of course to know for sure, as you mentioned, I would need to put it on an o-scope. However, there was enough output to charge the computer and the TT batteries and run the other things which need AC. Although changing jets is inconvenient I may indeed have to "get use to it".

rsdata · 07-23-2017, 11:10 AM

Quote:

not good is because a computer timing is keyed on the 60 cycle sine wave,

once upon a time this was partially true...

but not so in the last 30 years...

where does the laptop get the sine wave when operating on battery only?

rsdata · 07-23-2017, 11:47 AM

add a hard start capacitor to your AC for about $12 and 30 minutes of your time before re-jetting...

tutorial here...

http://www.forestriverforums.com/for...nit-94386.html

Evereddie · 07-23-2017, 01:18 PM

Quote:

Originally Posted by rsdata

once upon a time this was partially true...

but not so in the last 30 years...

where does the laptop get the sine wave when operating on battery only?

I have the feeling that the un-pure sign wave is messing with the switching power supply therefore messing up the computer but not because the computer 'locks' onto the 60 cycles. Just trashy power.
Maybe.

Big Vic · 07-23-2017, 01:50 PM

What about a soft start device like the Micro-air easy start? Significantly decreases the amps needed to start and run the A/C. Lots of threads on this device in this forum.

jkoenig24 · 07-23-2017, 02:12 PM

With generators, you get what you pay for. That's why Honda and Yamaha cost more (although, even those premium brands are not exempt from the laws of physics). The Honda Handi 3KW did foul a spark plug while I was in Yellowstone but, that was after a week at over 6000' MSL. Once the spark plug was cleaned, I was good to go. That Honda Handi had no trouble running the AC (as well as other 110VAC appliances) in my 2010 Casita Spirit Deluxe Travel Trailer. The Hondas & Yamahas also have longer duty cycles than the "off brands".

jimmoore13 · 07-24-2017, 01:12 PM

I suspect a bad generator...

Just in case, be sure you're generator is running in the max power mode rather than the power conservation mode. Virtually all generators have a switch to allow the generator to save fuel and put out a modest amount of power (current) for light loads. But high-demand devices attempt to start under what amounts to "brown-out" conditions if they try to start while the generator is idled down. The generator's reaction time is too slow to deliver full power for the highest-demand portion of an air-conditioner or high-power microwave start. Give the gen-set a fighting chance and throw the switch to full power mode.

It's true that engines make less power at altitude. It's also true that a carburetor jetting adjustment will make the engine run better. An engine setup to run at or near sea level will be too rich at altitude, because there is less air in the air/fuel mix. (Fuel injection automatically adjusts for this in cars.) A high-altitude main jet will improve performance and restore some power...it will also prevent plug fouling. Of course, if you routinely run the gen-set at sea level, it will run too lean with a high altitude jet, and running lean may hurt the engine.

Frankly, 4000 feet just isn't that high. Again, I suspect a bad generator. MANY of the "knock-off" brands essentially fail right out of the box. You're inverter/generator section may not be performing up to snuff. I doubt that it's delivering full-rated power. And your concerns that the machine fails to deliver clean power at the modest altitude of 4000 feet is just further evidence that something's not right. If this thing is throwing power spikes and square waves at 4000 feet, you'd be wise to stop using it.

Back to altitude: This calculator is good for estimating power loss. Enter your altitude and enter 100 HP. The raw HP loss will appear as a percentage as well as an actual HP drop. Wallace Racing - Braking HP Loss at Altitude Calculator

I have a Generac ix2200...also a Chinese knock-off brand. My test was to bring it home and plug in my over-range microwave and vent hood...and run. I'm at 8300 feet! No problem, despite the fact that my power loss at altitude is 25%. I did set the engine switch to full power mode for that test. But in the field, using the much-lower power microwave in the camper, I run the gen-set on the power-saver mode. When we start the microwave, there's a momentary pause, the generator engine "accelerates," and the microwave is happy. The engine also runs cleanly enough to not warrant a change of main jet. After 4 years of heavy service camping AND as a backup generator, it's still on it's factory plug and starts on the 2nd pull.

Be sure your air filter is pristine at altitude. Any air intake resistance will exacerbate the fuel/air mixture problem.

A friend bought the same Generac, and he could not run his microwave in Denver - 5280 feet. Despite a 3000 feet altitude advantage, the inverter/generator portion of the machine was not putting out nearly as much power as mine does. In other words, my Generac works as claimed, and his had a manufacturing defect. He returned it and blew an extra $400 on a Honda. His Honda has no trouble with the microwave test. But neither does my Generac. We often camp together, and my Generac performs as well as his Honda.

If your Champion is still under warranty, I suggest you find a service shop that can perform a load bank test on your generator. The fact that its output so so marginal that 1500 feet of change in altitude at the relatively low altitude of 4000 feet leaves it gasping AND putting out square waves and spikes suggests it's malfunctioning and delivering less than it's rated capacity. Unlike my "foolproof" microwave test on a small (2 K) generator, finding the "right" household load to verify the performance of your 3.5 KW generator will be much more difficult. It's VERY unlikely that you have a 13,000 btu window AC unit, so you'll need help.

Furthermore, "resistive" loads, like heaters and quartz lights, won't test the surge starting power of the gen-set. You could probably pile on what appears to be 4 KW in resistive loads and the gen-set would appear to deliver. A load bank test can give you a performance chart, including startup capacity, that would be handy for a warranty claim.
Load bank tests are typically performed on industrial generators...6 or 8 cylinder diesels putting out 50 to 500 KW. But there should be someone...perhaps at an ONAN dealer...with a load bank scaled for a 3.5 to 5 KW generator. Considering the value of the Champion, I suspect spending $100 on the load bank test will be worth the investment.

As for the hard-start capacitors...that's a GREAT suggestion under any circumstances. A capacitor gives the compressor motor a kick in the ass to get it going. Replacing the conventional starting capacitor with one that has substantially greater capability is a good solution. It's akin to replacing your group-24 12-volt battery with 4 to 6 6-volt batteries wired to deliver 12 volts. The bank of batteries has essentially an infinite reserve of power vs. the "just enough" supply in your standard 12-volt group 24. The bigger capacitor simply holds more and can deliver it for a longer time. Once the compressor motor is running, its power demands drop considerably, and the capacitor seizes the opportunity to recharge for the next motor start. That's not just a kluge. It's a good way to protect the compressor.

In fact, if it weren't for the "unclean" power delivery at 4000 feet, I'd suggest looking at the start capacitor on the AC first. But the inability of your laptop to tolerate the power coming from the generator is a good sign that the generator has a manufacturing defect.

Something's not right with your generator.

jimmoore13 · 07-24-2017, 01:20 PM

Quote:

Originally Posted by jkoenig24

With generators, you get what you pay for. That's why Honda and Yamaha cost more (although, even those premium brands are not exempt from the laws of physics). The Honda Handi 3KW did foul a spark plug while I was in Yellowstone but, that was after a week at over 6000' MSL. Once the spark plug was cleaned, I was good to go. That Honda Handi had no trouble running the AC (as well as other 110VAC appliances) in my 2010 Casita Spirit Deluxe Travel Trailer. The Hondas & Yamahas also have longer duty cycles than the "off brands".

I won't argue that Honda and Yamaha make top-quality products. But, my Generac (off-brand) ix2200 also delivers the goods....for 4 years now, both for camping and for home backup power. And, despite factory (sea-level) carb jetting, I am still running the original plug with no replacements or cleanings. I live at 8300 feet and camp higher.

My advice for ANY brand new generator is to really test it before choosing to keep it. For a typical 2KW generator, that means hooking a big home microwave to the generator (using a 12-3 extension cord) and seeing if the gen-set can start it and run it reliably. Like an AC unit, startup demands by a 1500 watt microwave are severe, and if your 2K generator can run your over-the-range microwave, it's a good generator. If it can't, return it and try another. I'd do that to save $400 any day.

Bacchus · 07-24-2017, 02:00 PM

Jim, and everyone else I want to thank you for your replies. I have learned a lot and here is what I have decided to do:
1, Because the generator/inverter is still under warranty I called Champion and they agree that something is wrong with the internal computer of the unit and are sending me a new one.
2. Then are also sending me a new jet for the carb.
3. I will be installing a hard start capacitor.
One thing I would like to mention is that the people working at Campion are very easy to work with and seem wiling to do whatever it takes to make sure the product works properly.
I also agree with everyone who said that Honda is the best but to replace what I have with a Honda would cost twice as much as I paid for this unit.

mikakuja · 07-24-2017, 02:15 PM

I upgraded from a Champion open frame 4000w to a Champion 3100 inverter. We have been using it for 2 seasons now and have had zero issues at high elevation or sea level (winter or summer) running the AC or any other appliances off of it.
Hopefully the parts they are sending you rectify the issues...
Good Luck.

jimmoore13 · 07-24-2017, 02:26 PM

Quote:

Originally Posted by Bacchus

Jim, and everyone else I want to thank you for your replies. I have learned a lot and here is what I have decided to do:
1, Because the generator/inverter is still under warranty I called Champion and they agree that something is wrong with the internal computer of the unit and are sending me a new one.
2. Then are also sending me a new jet for the carb.
3. I will be installing a hard start capacitor.
One thing I would like to mention is that the people working at Campion are very easy to work with and seem wiling to do whatever it takes to make sure the product works properly.
I also agree with everyone who said that Honda is the best but to replace what I have with a Honda would cost twice as much as I paid for this unit.

Well, talk about a great outcome!!

When I eventually replace my Generac, I will surely buy a Champion. That's amazing customer service.

Bacchus · 08-13-2017, 07:28 AM

Champion did send a new "control unit" and I installed it. One thing about the Champion is its ease of service, once the outer cover was removed only one bolt holding the control unit in and 5 connectors to remove, very easy. It did correct the altitude problem up to a moderate altitude of 6000 ft. but still am not getting clean power. Called Champion again and after talking to them took it to a warrantee shop for them to fix it, what a waste of time. They said they contacted Champion and was told to either use a "surge protector" of stick a 3ft rod in the ground and connect it to the generator to prevent a "floating ground", both of which are ridiculous for the problem I am having, however I tried both to satisfy Champion the next time I call them. I can't call them this coming week because I am going camping. The saga will continue in a week or so.

Skyliner · 08-13-2017, 06:38 PM

Sorry you are having an issue with your generator.

My new Champion Inverter 3400/3100 runs my 15k BTU airconditioner and all electronics with no issues. This is at 6600 feet with NO high altitude jet. The jet is in the mail and I probably won't have it installed in time for our excursion to our usual 10,000 ft ASL camping site.

Only problem I've had with my Champion is that the factory spark plug was cracked resulting in a no spark condition. A new NGK plug fixed it.

Good luck and be persistent with Champion to get your generator fixed.

Do you know anybody else with an inverter generator to test your laptop on? It is possible your switching powersupply is a little finicky. I'm fortunate in that my laptop is the old transformer type with a full wave rectifier that I feel provides cleaner DC to the laptop.

Also, please try plugging your laptop into your generator to see if it has the same problem. You may be getting some stray RF "noise" from the switching power supply in your power converter.

Bacchus · 08-13-2017, 07:20 PM

Fortunately I have another, Ryobi 2200w, inverter and everything works fine both directly from the generator/inverter and inside the TT. I have also tried my Macbook Pro directly from the Champion and inside the TT with the same unsatisfactory results. I am going on a boondocking trip this next week and will take both inverters so I can safely run my electronics and also the AC, I will run an extension cord from the Ryobi to the computer. When I return I will be on the phone with Champion again, the good thing is that so far their customer service has been great.

beachlife · 08-14-2017, 07:31 AM

Quote:

Originally Posted by rsdata

once upon a time this was partially true...

but not so in the last 30 years...

where does the laptop get the sine wave when operating on battery only?

The laptop operates on DC current. The charger is AC. There will be no cursor movement issues with any laptop. I've had bad laptop chargers affect the performance of a computer, but it isn't directly related to wall power and the laptop itself.
That said, there are many ways to ensure you can get the perfect output you require, like an inverter. A small solar charger can maintain the battery and free you from a generator altogether if you require only occasional 110 use. That's what I do.

And yes, rejetting carbs is commonplace because of the difference in air pressure/density. Before FI cars, we had to adjust up the mountain, and then once we were over we did it again.

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