Does generator brand really matter in power output?

[tporter]

I bought an inexpensive generator to use with our fifth wheel which is a 2014 Solitude. The generator is a Predator with 4000 watts maximum, 3200 running watts. The generator runs one air condition (15k) for a few minutes then the breaker trips on the unit. The power cord is plugged into a 120/220v, 13A plug. The plug is a four prong twist lock. The only other plugs on the generator are two standard plugs that can handle a standard extension cord. With the above information I should be able to run one air conditioner shouldn't I? When the a/c was running you could tell that the generator was working due to a change in the motor noise. I have the Progressive electrical management system, it never stopped power to the with wheel.

Eventually I will be buying two Honda 2000's for the fifth wheel but after buying the inexpensive 4000 watt unit I question that the 2 Hondas can power an air conditioner. Does brand really make a difference in performance? Can two 2000's run an air conditioner, if not what do I need?

[Timon0x31]

One thing you want to check is the regulation of the output. You don't want something that cannot hold a constant output and frequency. Typically low cost units are not as good in this area.

Personally I'd love to see a DC generator, batteries and an inverter with a solar option. You always run from the batteries with the generator kicking in on high loads when needed or when the batteries need charging. If you add solar it would just be another source to charge the batteries. The only problem is that no one yet make this commercially for RVs

[thompsons 369rl]

A 3200 watt gen should certainly be able to run one A/C unit. Does the breaker (I assume you mean the breaker in the gen unit) trip only on A/C start-up? Does the gen adaptor plug directly into you 50 amp plug? Have you tried running a combination of other items like the microwave etc to see lf that works. So many questions.....

[tporter]

The breaker trips on the generator after the a/c has been running for a few minutes. Progressive management system hasn't shut the power down to the trailer yet. I haven't tried running anything else yet as I bought the generator to run the a/c unit. I did borrow a 5200 surge, 4000 watt generator to see what it would do. This ran the a/c fine. It is a Generac with a Honda motor and is very loud.

[thompsons 369rl]

According to the Dometic manual, the minimum generator size to run a single 13,500 or 15,000 BTU unit is 3.5kw and 5kw for two units. Of course they don't mention if that's running watts or peak watts. I would have thought a 4000 peak watt gen would do the job. I would contact Dometic (if that's what you have) and ask. It's also possible there's a problem with the gen.

[Retread68]

"The power cord is plugged into a 120/220v, 13A plug".
Right there is part of your problem. Not knowing the model number of your 15kw Dometic A/C unit, I looked at several specs and found those compressors pull 12.7-12.9 amps (depending on model), with a locked load of 79 amps, plus the fan pulls 2.5 amps; which tells me you're over capacity or teetering on capacity of the plug depending on A/C model and voltage loss on the line.

To answer your question about "cheap" gensets vs more expensive ones, let me say this .... Typically you get what you pay for.

[tporter]

Thanks for your help. The generator has been returned and I will buy a different one.

[Joe & Lori]

One other item to keep in mind. Naturally aspirated engines lose 4% for every 1,000ft above 1,500ft elevation. So if you happened to be in the mountains @ 6,500ft you would lose 20% of your rated power. 4Kw is a stretch for two A/C units.

[WhittleBurner]

There is a temperature lose of 3.5 degrees per 1000 feet. Going from 2000 feet to 6500 feet a 90 degree day would only be 75 and you may not need to run both.

[Retread68]

If I need to run the A/C without shore power I hook up a 10Kw Generac to the 5er. Yeah - it's loud, but it keeps the bears away. In fact it works so well we haven't seen a bear here in Dyersburg, TN for at least a couple years ! If I'm trying to be discrete and not disturb the neighbors all night long I'll hook up the 6.5Kw Generac. It's about 3 db quieter. Wonder why the neighbors keep moving away?