Generator Undersized

[lakebuster]

I have done some research on Cummins/Onan generators, the 5.5kw and 7kw have the same size engine, but operate at different rpm's. My unit has 3 A/C's that can't be powered at same time by the 5.5KW but could possibly, with the 7KW
Has anyone learned the secret to converting there 5.5kw to the 7kw?
Look at the engine CC size and then look at the carb part# identical they operate at 2400 the 5.5kw and 2880 RPM for the 7kw and both make their power at 60Khz......Am I missing something, if I raise the rpm's on my 5.5kw then the Khz goes to high also.....

[arlan in arizona]

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[eightydo]

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[azdryheat]

Onan says the 7kw has an amp output of 58.3 amps while the 5.5kw has a 45.8 amp output. Their website says the 7kw will power 2 a/c but doesn't mention 3: "Runs one or two air conditioners with power to spare".

[lakebuster]

Reworded original, but just do not understand this phenomenon to me!

[lakebuster]

If my camper was closer, I would walk back and see what size breakers for my A/C units, just guessing 15A, So X 3=45A so if true the 7kw should work.

[Wanderer]

AC units need 20 amps to start. Generator output listings are for maximum startup loads, not running loads.

Just because the motors are the same size doesn't mean the generators are. The motor just drives the generator.

[macman83]

The engine size may be the same, but I would bet that the generator unit is completely different. The windings are probably bigger and that is how it runs at a higher RPM while still making 60HZ. I would bet that you can't make a 5.5 generate 7KW. (but I am no expert, just a mechanic)

[lakebuster]

True, never thought about the windings side all good points. Off subject but here it is 9pm been home since 5pm and still not ready to pull out for camping in the morning...checking air pressures, shot of grease in the hubs, hooking up to the truck, loading clothes and loading up the groceries, was going to load the toys, but exhausted from working/fighting traffic so gave up to finish bright and early or really whenever I wake up! Getting a little too old for the weekend warrior camping!

[arlan in arizona]

Originally Posted by lakebuster

so gave up to finish bright and early or really whenever I wake up!

That sounds just like me! More off subject. Have you hit the CAT scales yet. Just wondering.

[lakebuster]

Nope not yet, actually where do you go to get weighed, you talking about the scales off of the interstates?

[arlan in arizona]

Originally Posted by lakebuster

Nope not yet, actually where do you go to get weighed, you talking about the scales off of the interstates?

Yes, most of them would be off of the interstate. Like a a Pilot station or Loves, etc. I am not sure what the stations are in your part of the country. Out West they are called CAT scales. I just looked you have Pilot, Petro Stopping Center and La Place Travel Centers. Correct or did I miss it?

Here is a link. CAT Scale Locator | CAT Scale

They cost you about 10 bucks. Pull in, get your axles in the right spot, it's easy. They them first weight, private vehicle, pull off the scales and go in and get your weigh ticket. If you decide to weigh there is a great app that you enter your information in and it give you stuff like this.

Report

TV Weight W/ Trailer Attached: 12800
TV Weight: 9440
Trailer Kingpin Weight: 3360
Trailer Gross Weight: 19240
TV & Trailer Combined Weight: 28680
Vertical Load (Kingpin): 17%

Safety Margin VS. Overload

TV Front Axle Weight: -720
TV Rear Axle Weight: -2070
TV Gross Weight (GVW): -1200
TV Combined Weight (GCW): -1820
Hitch Tow (GTW): -5760
Vertical Load (Kingpin): -2890
Trailer Gross Weight (GVW): 240

The minus number are the ones you want to see. You can see in this report I am good except for the last line.

[eightydo]

Arlan; What is the name of APP, does it go to an Iphone or Android?

[arlan in arizona]

Originally Posted by eightydo

Arlan; What is the name of APP, does it go to an Iphone or Android?

It is for iPhone and Android.

FIFTH WHEEL ST. for RVs – Towing Weight Apps | The Only 13 Point Towing Weight Safety Report

[eightydo]

Thank you

[arlan in arizona]

Your welcome.

[Moto4play]

Originally Posted by arlan in arizona

Yes, most of them would be off of the interstate. Like a a Pilot station or Loves, etc. I am not sure what the stations are in your part of the country. Out West they are called CAT scales. I just looked you have Pilot, Petro Stopping Center and La Place Travel Centers. Correct or did I miss it?

Here is a link. CAT Scale Locator | CAT Scale

They cost you about 10 bucks. Pull in, get your axles in the right spot, it's easy. They them first weight, private vehicle, pull off the scales and go in and get your weigh ticket. If you decide to weigh there is a great app that you enter your information in and it give you stuff like this.

Report

TV Weight W/ Trailer Attached: 12800
TV Weight: 9440
Trailer Kingpin Weight: 3360
Trailer Gross Weight: 19240
TV & Trailer Combined Weight: 28680
Vertical Load (Kingpin): 17%

Safety Margin VS. Overload

TV Front Axle Weight: -720
TV Rear Axle Weight: -2070
TV Gross Weight (GVW): -1200
TV Combined Weight (GCW): -1820
Hitch Tow (GTW): -5760
Vertical Load (Kingpin): -2890
Trailer Gross Weight (GVW): 240

The minus number are the ones you want to see. You can see in this report I am good except for the last line.

I am assuming these are actual numbers from your weigh in, did you have the RZR in the trailer?

[arlan in arizona]

Yes, the RZR was loaded in the trailer. The RZR is loaded with winch I carry annother three gallons of fuel on it another gallon and a half of water. Cargo box with tools, etc. 60 gallons of gasoline in the tanks, propane full, water at only 35 gallons. I have gained some weight with things like four solar panels, four six volt batteries, Wingard Traver automatic satellite dish, big DVR receiver and Wave Catalytic Heater . Changing my tires over to the 14 ply G rated Goodyear G614's added about one hundred fifty pounds, 27 pounds for window awnings. Plus personal stuff and food.

I have removed both guest mattresses, that funky table that is supposed to be used at the couch, both garage chairs, stools, patio enclosure, the sink covers.

I have been trying hard to make weight but it is difficult. The wife is great about what we pack so I can't blame her.

We kind of drifted off of the OP original post on the generator. Sorry.