Reply
 
Thread Tools Display Modes
Old 03-19-2020, 10:36 AM   #1
Member
 
Join Date: Jun 2019
Location: Crested Butte CO
Posts: 40
Champion 3400 Generator at altitude run 15K AC?

I am shopping for a generator that will operate my Coleman Mach 15k AC on my 2020 2512S TT. I have searched the forums and read a LOT of info on generators running AC units, however could not find much concerning altitude.

I am most interested in the Champion 3400 model with the remote start as it appears that most folks have had success with this unit and the remote start sounds like a great feature.

I understand that: 1) altitude reduces power output 2) that I could run 2 2,000watt generators in parallel 3) I could install Easy Start on my AC unit.

My preference would be to have only one generator and not to have to install Easy Start if possible (but willing to do so if necessary).

DOES ANYONE have experience running a Champion generator ( on gas) to power their 15k AC unit at altitude.

We live at 9,000 in Colorado but most camping will be at lower altitude ( anywhere between 2,000 and 6,000).

Thanks in advance!
Dreedo is offline   Reply With Quote
Old 03-19-2020, 11:36 AM   #2
Senior Member
 
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 8,997
If all other heavy loads are turned off the Champion 3400 (I assume inverter type) generator should run the 15,000 BTU A/C even at altitude.

What might keep it from doing so is if your batteries are low and the converter is drawing a lot of current in order to charge them. That adds up to 1Kw to the load. Also, make sure your water heater's electric element is shut off.

It's accepted that a gasoline engine looses about 3% of it's power per 1,000 feet in altitude gain. At 8,000 feet that would be 24%. Since horsepower and electricity have a fairly direct relationship that means that a 3400 watt starting power rating would be more like 2500-2600 watts. A Coleman Mach 15 is "spec'd" at 14.8 amp or 1776 watts. That falls within the capabilities of the generator in question.

Now to test the theory, can you plug into a 15 amp residential output and will the A/C start and run? If so it should also on that generator at 8,000 feet.

One note however, if you run the generator at 8,000 feet under load it MIGHT be necessary to change the main jet in the carburetor for the higher altitude. Champion will send you one at no charge. Not hard to change but you do not want to use the high altitude jet at low altitudes as the engine will run too lean. You'll know if you need the high altitude jet as the generator will run like the choke is partially on and it will sound like it's struggling to maintain speed.

As a side note, if you get a dual fuel model (I have one) you don't need to worry about jetting as the LPG regulator takes care of it on it's own.

In closing, my Champion inverter (I have the 3500w unit which is pretty much the same as the 3400 watt unit) performed flawlessly while camping in N. New Mexico ABOVE 8,000 feet and I didn't need to change the jet. I was able to run both A/C and Microwave at the same time although the A/C had to be running before I could start the microwave, not the other way around.

Hope some of this helps.

Mike
__________________
"A wise man can change his mind. A fool never will."

"Sometimes you're the dog, sometimes you're the tree"

2018 Flagstaff Micro Lite 25BDS
2004 Nissan Titan
TitanMike is online now   Reply With Quote
Old 03-19-2020, 11:40 AM   #3
Member
 
Join Date: Jun 2019
Location: Crested Butte CO
Posts: 40
Quote:
Originally Posted by TitanMike View Post
If all other heavy loads are turned off the Champion 3400 (I assume inverter type) generator should run the 15,000 BTU A/C even at altitude.

What might keep it from doing so is if your batteries are low and the converter is drawing a lot of current in order to charge them. That adds up to 1Kw to the load. Also, make sure your water heater's electric element is shut off.

It's accepted that a gasoline engine looses about 3% of it's power per 1,000 feet in altitude gain. At 8,000 feet that would be 24%. Since horsepower and electricity have a fairly direct relationship that means that a 3400 watt starting power rating would be more like 2500-2600 watts. A Coleman Mach 15 is "spec'd" at 14.8 amp or 1776 watts. That falls within the capabilities of the generator in question.

Now to test the theory, can you plug into a 15 amp residential output and will the A/C start and run? If so it should also on that generator at 8,000 feet.

One note however, if you run the generator at 8,000 feet under load it MIGHT be necessary to change the main jet in the carburetor for the higher altitude. Champion will send you one at no charge. Not hard to change but you do not want to use the high altitude jet at low altitudes as the engine will run too lean. You'll know if you need the high altitude jet as the generator will run like the choke is partially on and it will sound like it's struggling to maintain speed.

As a side note, if you get a dual fuel model (I have one) you don't need to worry about jetting as the LPG regulator takes care of it on it's own.

In closing, my Champion inverter (I have the 3500w unit which is pretty much the same as the 3400 watt unit) performed flawlessly while camping in N. New Mexico ABOVE 8,000 feet and I didn't need to change the jet. I was able to run both A/C and Microwave at the same time although the A/C had to be running before I could start the microwave, not the other way around.

Hope some of this helps.

Mike

Thanks Mike! Very helpful!
Dreedo is offline   Reply With Quote
Old 03-19-2020, 12:15 PM   #4
Senior Member
 
NMWildcat's Avatar
 
Join Date: Jun 2012
Location: Southern NM
Posts: 6,121
I have two Honda EU2000is. I have run them between sea level and 9k. I've never really noticed any change in what I could or could not run together at extreme elevations. Never had to change any jets. Of course, with the 2000s in parallel, I have a bit more wiggle room than one 3400. So, I, or friends I'm with, haven't experienced problems running what we usually run due to loss of power folks always talk about at high elevations.
Several of my friends have the 340O. Like mentioned above, you can run the 15k a/c, but not much else. My friends will usually turn off converter and not use anything else while running a/c. If you do start something else after the a/c starts up, when the compressor cycles, you will probably lose power. I watch my friends restart the 3400 frequently when doing this
And at higher elevations, you really don't have to run the a/c much, or for long periods, so I wouldn't be too worried about it.
__________________
Scott and Liz - Southern NM
2012 Wildcat Sterling 32RL - w/level up (best option ever)
2007 Chevy 2500HD 4dr short bed Duramax w/allison
Reese Fifth Airborne air ride king pin coupler with Sidewinder
NMWildcat is online now   Reply With Quote
Old 03-19-2020, 02:08 PM   #5
Senior Member
 
SailorSam20500's Avatar
 
Join Date: Jun 2016
Posts: 3,267
As you've probably read in your prior searches, the issue is going to be the LRA current draw at startup. It's a momentary issue, but it is the limiting factor. You will need to get replies from others and make sure you are checking identical AC models. Airxcel makes several 15k units. I looked up two and they spec LRA at 50.5. So, it is a question of whether or not your generator will tolerate that load. Worst case if it doesn't work, get the MicroAir Easy start, by all reports it will reduce the LRA requirement enough. Airxcel had a presentation at last years Frog International Rally. I asked their representatives straight out, "does installing a Micro Air Easy Start void your warranty?" The answer was short and clear: "No".
__________________
Al
Save the Earth. Itís the only known planet with Beer.
There are times where my greatest accomplishment is keeping my mouth shut...

S.E. Mich. Flagstaff 26FKWS / 2019 F-150 3.5 EcoBoost SCrew Propride
SailorSam20500 is offline   Reply With Quote
Old 03-19-2020, 02:31 PM   #6
Senior Member
 
bedubya's Avatar
 
Join Date: Jun 2017
Posts: 466
I had a Champion 3100 watt gasser. It puts out 2800 running watts. In Pueblo (4200 feet), my 13k A/C overloaded it. I returned it for a 3500 watt (3200 running watts) unit which works fine there.

According to my Champion owners manual, "Engine power and generator output will be reduced approximately 3Ĺ% for every 1000 feet of elevation above sea level." So at 6,000 feet, your 3100 running watts will actually become 2449 watts.
If I were doing a lot of higher elevation camping, I think I would get 2 Harbor Freight 2000 watt units and run 'em in parallel.
__________________

'17 Toyota Tacoma 4x4 TRD Sport
'17 Salem Cruise Lite 232RBXL
'08 Kawasaki Vulcan Classic 1500
Mickey the Rescue Project Schnauzer
Days Camped: 2017-39, 2018-61, 2019-64
bedubya is offline   Reply With Quote
Old 03-19-2020, 03:02 PM   #7
Member
 
Join Date: Jun 2019
Location: Crested Butte CO
Posts: 40
Quote:
Originally Posted by bedubya View Post
I had a Champion 3100 watt gasser. It puts out 2800 running watts. In Pueblo (4200 feet), my 13k A/C overloaded it. I returned it for a 3500 watt (3200 running watts) unit which works fine there.

According to my Champion owners manual, "Engine power and generator output will be reduced approximately 3Ĺ% for every 1000 feet of elevation above sea level." So at 6,000 feet, your 3100 running watts will actually become 2449 watts.
If I were doing a lot of higher elevation camping, I think I would get 2 Harbor Freight 2000 watt units and run 'em in parallel.
Thanks for info. If you can run it in Pueblo with 3100, I would think that I could run a 15K in Pueblo with a 3500.
Dreedo is offline   Reply With Quote
Old 03-19-2020, 04:12 PM   #8
Site Team
 
bikendan's Avatar
 
Join Date: Jan 2007
Location: Camano Island, Washington
Posts: 22,537
Quote:
Originally Posted by bedubya View Post
If I were doing a lot of higher elevation camping, I think I would get 2 Harbor Freight 2000 watt units and run 'em in parallel.
I would never buy those as they are way too loud for a 2000w inverter generator. At 65db, it's a lie that HF calls it "super quiet". My Honda 2000i is 53db and my $300 Champion 3500/4000w open frame contractor style generator is 65db, the same as HD's Predator 2000w inverter generator and I would never use my Champion open frame contractor-style generator in a campground.
The better buy would be the Predator 3500w inverter generator with a 57db rating.
__________________
Dan-Retired California Firefighter/EMT
Shawn-Musician/Entrepreneur/Wine Expert
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package
Equalizer WDH
bikendan is offline   Reply With Quote
Old 03-19-2020, 08:04 PM   #9
Senior Member
 
dbledan's Avatar
 
Join Date: Jan 2017
Location: KS
Posts: 2,222
Titanmike said most of what I had to say. Just one addition to help you.

I use my dual fuel 3400 on propane which drops the rating to 3050w to power my 15k coleman Mach III A/C. It does it in eco mode. It kicks off eco for a second when firing up with no easy start or any mods. The mach III uses about 12.5A when running. I have never been able to measure startup current. I leave the math on the rating drop.

I got the jet free after sending an email to champion as well but have never changed it as most of my camping is 3500ft or below and I used propane at altitude.
dbledan is offline   Reply With Quote
Old 03-19-2020, 08:30 PM   #10
Junior Member
 
25RockwoodinMO's Avatar
 
Join Date: May 2017
Location: Missouri
Posts: 17
Hard start cap already installed?

We just bought the Champion 3500 last weekend and have yet to unbox it. We are wanting to run it on propane for one of our two 15K air conditioners on our Rockwood 2906ws. A friend / coworker just ordered a new Flagstaff and the dealer told him any new units since 2018 come with the hard start cap installed, not sure if this is true. Our TT is a 2018 made in late 2017. I will have to look when we get it out of storage soon if we both stay healthy. Now I'm wondering if the 50 to 30 amp adapter energizes the front air unit or the one in the back? I guess I'll have to see how they're wired in the breaker panel. A lot of questions I know, but I saw a few YouTube videos where people said the champion 3400 / 3500 would run a 15K air conditioner so I took the chance and bought it. Didn't mean to hijack the thread just wanted to throw out a few comments and questions thanks! Everyone stay healthy! Chuck
25RockwoodinMO is offline   Reply With Quote
Old 03-19-2020, 09:40 PM   #11
Member
 
Join Date: Jun 2017
Posts: 75
I am at 4300 feet and it would not run my 13.5k Dometic. Ended up buying a 2nd unit. I even took it back to Cabelaís because i thought something was wrong with it. Champion finally had me run some tests with everything turned of except the AC and nada.
__________________
Tundra 2017 CrewMax retired for a RAM Laramie 2500
FR 2017 T2460 EVO
Andersen sway control
Cahriad is offline   Reply With Quote
Old 03-19-2020, 10:04 PM   #12
Senior Member
 
SailorSam20500's Avatar
 
Join Date: Jun 2016
Posts: 3,267
Quote:
Originally Posted by 25RockwoodinMO View Post
We just bought the Champion 3500 last weekend and have yet to unbox it. We are wanting to run it on propane for one of our two 15K air conditioners on our Rockwood 2906ws. A friend / coworker just ordered a new Flagstaff and the dealer told him any new units since 2018 come with the hard start cap installed, not sure if this is true. Our TT is a 2018 made in late 2017. I will have to look when we get it out of storage soon if we both stay healthy. Now I'm wondering if the 50 to 30 amp adapter energizes the front air unit or the one in the back? I guess I'll have to see how they're wired in the breaker panel. A lot of questions I know, but I saw a few YouTube videos where people said the champion 3400 / 3500 would run a 15K air conditioner so I took the chance and bought it. Didn't mean to hijack the thread just wanted to throw out a few comments and questions thanks! Everyone stay healthy! Chuck

Because of the way the wiring works, you will be able to run either AC unit but almost certainly not both at the same time. The 30-50 dog bone will feed both 50 amp leads into your trailer. BUT, you will have a max of 30 usable amps available. That is significantly less than the two 50 amp feeds that provide a total of 100 usable amps (50 amps on each of the 2 leads).
__________________
Al
Save the Earth. Itís the only known planet with Beer.
There are times where my greatest accomplishment is keeping my mouth shut...

S.E. Mich. Flagstaff 26FKWS / 2019 F-150 3.5 EcoBoost SCrew Propride
SailorSam20500 is offline   Reply With Quote
Old 03-20-2020, 10:25 AM   #13
Senior Member
 
Join Date: May 2017
Location: NE Wyoming
Posts: 105
Smile

I have a Champion 3400 inverter generator that I use at 8000 to 9000 feet. It will not run my 15k AC. I have problems running my microwave in the morning when the batteries are charging. I went to a Honda 7000i that is fuel injected and I supposedly do not have to de-rate at altitude. It is heavy (300#) but is very quiet. My camping neighbors like the quiet part. Champion is noisier. I have a portable hoist to move my Honda in and out of my truck. The Honda runs everything in my trailer at the same time and runs for 18 hours at 50%. The wife is now a happy camper. Best money I have spent.
Grumpy7159 is offline   Reply With Quote
Old 03-20-2020, 11:02 AM   #14
Member
 
Join Date: Jun 2019
Location: Crested Butte CO
Posts: 40
Wow... thanks for the info, that's a bit more than I need for occasional use. Most camping will be at 2,000-5,000 ft, and I don't need to run everything at once.
Dreedo is offline   Reply With Quote
Old 03-20-2020, 11:42 AM   #15
Senior Member
 
Join Date: Jul 2017
Location: North of Seattle, WA
Posts: 8,997
Quote:
Originally Posted by Grumpy7159 View Post
I have a Champion 3400 inverter generator that I use at 8000 to 9000 feet. It will not run my 15k AC. I have problems running my microwave in the morning when the batteries are charging. I went to a Honda 7000i that is fuel injected and I supposedly do not have to de-rate at altitude. It is heavy (300#) but is very quiet. My camping neighbors like the quiet part. Champion is noisier. I have a portable hoist to move my Honda in and out of my truck. The Honda runs everything in my trailer at the same time and runs for 18 hours at 50%. The wife is now a happy camper. Best money I have spent.
Sadly, you still have to "de-rate" for altitude. The only benefit to fuel injection is that fuel mixture is more closely regulated than with a carburetor. If equipped with an oxygen sensor the computer will adjust the mixture for the altitude so there are fewer un-burned hydrocabons discharged in the exhaust.

At altitude the engines produce less horsepower because of the lower amount of oxygen in the air and since horsepower translates to power output, you get less, period, law of physics. If an engine is 100% efficient and there are no generation losses, one horsepower will yield 746 watts. Less horsepower due to altitude, less power produced. In the real world a gas engine needs to from 1.5 to 2 times larger than the equation for perfect conversion.

Only way to overcome the loss is to use a super/turbo charger which now makes the engine think it's operating at sea level.

Fuel injection is nice on several levels but it doesn't make an engine produce more Hp at altitude. Also, having a 7kw generator has a lot more reserve power so naturally altitude will not be as noticeable as it would with a genset half the size.

Curious as to how loud it is compared to another Honda half it's size.
__________________
"A wise man can change his mind. A fool never will."

"Sometimes you're the dog, sometimes you're the tree"

2018 Flagstaff Micro Lite 25BDS
2004 Nissan Titan
TitanMike is online now   Reply With Quote
Old 03-20-2020, 11:58 AM   #16
Grammar Pedant
 
67L48's Avatar
 
Join Date: Aug 2017
Location: Frederick, CO
Posts: 1,550
Yep, you can't outrun physics and thermodynamics. Altitude robs power. One correction I'd make is that it's generally 3% per 1,000' feet above nominal. Most engines are rated at some altitude above sea level -- 500 feet is common. So, 8,000' doesn't reduce power by 24% ... it reduces power by 22.5%. Doesn't change the story much, if at all. May be a bit pedantic.

The only way to overcome altitude effects (or at least combat against them) is with some kind of supercharger or turbocharger. I don't think there are any supercharged or turbo generators out there.

I have an old Honda 600EX generator that started life out in the 1980s in Washington (near sea level). I now use it at 10,000'. No issues with its operation -- I didn't have to rejet. On the other hand, my son rejetted his Honda CRF230 and it runs MUCH better at the 4,000 - 6,000' he rides at. So, different engines and different uses may have different jetting needs.

A 15,000 BTU generator will need 3,200 - 3,500 W to start and then 1,500 - 1,800 W to continue running. I'd use those numbers to size my generator needs. When I read reviews on the 3,200-3,500 W generators, I find a sort of mixed bag of people who have good experiences running A/C and those who do not.

I think the reason is that this combination is right on the hairy edge. If the tolerances stack in your favor, then running a 15K BTU A/C at 6,000' with a 3,400 W generator will be fine. If the tolerances swing a bit in the opposite direction, you'll be popping breakers.
__________________
Every time you use an apostrophe to make a word plural, a puppy dies.

TV: 2019 F-350 Lariat 4WD CCSB 6.7 PSD 3.55, 3,591 lb payload
Former RV: 2018 Rockwood Mini Lite 2504S
Former RV: 2007 Fleetwood/Coleman Utah
Former TV: 2005 F-150 King Ranch 4WD SCrew 5.4L Tow Package
67L48 is offline   Reply With Quote
Reply

Tags
generator

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



All times are GMT -5. The time now is 11:26 AM.