1986 Dometic AC (rooftop)

[Revgmoney]

Rookie Question here:
I am going to buy a new generator/inverter to run my AC off grid.
How might I find the wattage of my rooftop AC unit?
1986 Komfort 21’ E-Class
Garrett

 

[sanda]

You want to test for amps. Mine have always been between 14 and 16 amps. You need at least a 30 Amp generator and then you may have to shed some power. (Turn off electric fridge/water heater/microwave). You would have to get a large battery bank and inverter to run an a/c.

 

[TheLooks]

Take down the ceiling assembly and there will be a label that will state the specs. Or look at the breaker that is marked AC and it most likely will be a 20 amp. AC will run on less but that is the size for amps on startup.

 

[Kevin D Pem]

Take down the ceiling assembly and there will be a label that will state the specs. Or look at the breaker that is marked AC and it most likely will be a 20 amp. AC will run on less but that is the size for amps on startup.

Maybe!!! Definitely not on eco mode. 3000w or more for a quiet inverter generator.

B.S.(Before solar), my approach to running ac was to run off inverter, and run a poor boy generator to keep the batteries topped. That worked!!!

 

[GypsyR]

An electrician's style clamp ammeter would tell you. To get at the wiring for a good reading one of those would require pulling the cover off the AC unit. Which you should be familiar with doing already as the things needs cleaning sometimes. Here's a cheap one: 6 Function Mini Clamp Meter
I bought a Predator 2000 watt inverter generator and found it runs one of my rooftop AC's at a time OK. Funnily it just purrs when running the vintage Dometic Penguin 13,500 BTU one but has to throttle up notably to run the very much newer Brisk II 15,000 BTU unit.

 

[Kevin D Pem]

An electrician's style clamp ammeter would tell you. To get at the wiring for a good reading one of those would require pulling the cover off the AC unit. Which you should be familiar with doing already as the things needs cleaning sometimes. Here's a cheap one: 6 Function Mini Clamp Meter
I bought a Predator 2000 watt inverter generator and found it runs one of my rooftop AC's at a time OK. Funnily it just purrs when running the vintage Dometic Penguin 1350 BTU one but has to throttle up notably to run the very much newer Brisk II 15,000 BTU unit.

Should have it's own braker. You can clamp the meter on there.

Buying a clamp meter that will not measure DCA is like going to Williams AZ, and not putting the extra miles on to see the Grand Canyon to save 20usd.

I know the predator line up is worthy! Back to the Grand Canyon!!!
The advantage of a few green backs are enormous!!!
Electric start
Enough power to remove concern if your ac will start.

Problem some have with them can be eliminated using sea foam in the gas. I know some people that put larger wheels on them, and roll them onto a front mounted platform on their truck.

Pay no mind to the 1350btu it is a typo!

I will still suggest the poor boy!!! The advantages offered are much greater than any image you must maintain!!!

 

[GypsyR]

Various coaches are different. I can't get such a clamp at my circuit breakers. Pretty sure on any of them with rooftop units you CAN access the power wiring by taking the cover off though. So I suggested that. It may be easier for him to get at the breakers on HIS camper but I have no way of knowing.

I originally thought I wanted a bigger generator. But I can't pick them up and carry them around. I tried, not happening. I can actually carry the Predator 2000's one in each hand. As long as I don't go far. Second huge advantage is that I can fit one sideways in one of my cargo compartments. No larger generator I know of will fit. Nor could I probably lift one in and out. Not really interested in carrying a generator externally but I would put them on a hitch rack if I needed both and/or wanted to carry them full of fuel.

Sorry Kevin, I have failed to quite understand your last sentence there. At all.

 

[Kevin D Pem]

My original post on this thread " poor boy generator". Auto alternator driven by gas motor!

Advantage lacking with quite inverter generators, is that the batteries take the place of capacitors, in circuit between the inverter and engine. That gives the engine time to come up to speed.

Some look at my setup and shake there head! But the only difference between your generator, and mine, is the engine is sized for running amps rather than starting amps, as yours is. The inverter is sized for nessisary starting load for all on-board equipment, as is the battery bank discharge c ratings.

How I regulate the output, both provides easily filtered constant output, as well as it limits amperage to keep the generator strong.
For the most part the engine runs at low RPM so lasts a long time, sipping gas. I get 4 hrs run time per tank (1/4 gallon tank), on a cooler day with 8000 btu ac.

The system mimics an inverter generator!!!! However to appreciate what I have, peoples looks, and comments have to roll off your back! For me that's not hard, because I know what I have is superior to ready-made solutions.

 

[TheLooks]

How bout a pic and detailed explanation of the specifics?

 

[GypsyR]

So there's another thread somewhere else on the forum with this "poor boy generator"? Because it sure isn't in this person's thread asking about his rooftop AC.