Air Conditioner/Generator

[Bob Salmi]

I recently bought a '94 Roadtrek. Everything works after considerable time spent on the generator. I had to replace the fuel pump and fix a vacuum leak. The port on the back of the carb was open not allowing the generator to idle. It runs good now and I can get the fan to run on the AC. The problem is the generator kills when the compressor starts. The generator will not ramp up to accommodate the needed load. Any ideas what my next step is?
Thanks, Bobhttp://www.classbforum.com/forums/images/smilies/whistling.gif

[BBQ]

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you might need to install the "Soft start" module on the air conditioner.

[InterBlog]

Hopefully an EasyStart would solve the OP's issue - caveated with the observation that, assuming all equipment is original, his rig was configured to run the roof unit WITHOUT an EasyStart, so why can it not be rehabbed to resume such operation now?

If I were the OP, I'd go with an EasyStart only after I exhausted every other possibility. There may be an easier and cheaper way (if only we knew what it was).

We installed an EasyStart last year and it's the cat's meow, BTW. But in our situation we are running the roof a/c off both the generator and our lithium battery, so our scenario is a bit different. There are a number of different ways to insult a 2,000 watt inverter to the point where it temporarily errors out, but the EasyStart is like the system's diplomat who intervenes and smooths all the ruffled electrical feathers so that everything boots back up again.

[SteveJ]

Assuming that is an Onan genny, there is no ramping up from idle. They should always run at 3600 rpm. You may not be done working on the genny. Carburetor issues?

On TDY near Torey UT.

[RT.SS]

Before tackling on the genset, probably good idea to rule out the AC is not at fault here. Plug the AC directly to a shore power and measure its initial current draw using a clamp Ammeter or something similar to “Kill-A-Watt” monitor.

[jaak1993]

The generator is designed to run at a constant speed to produce 60Hz AC. The only thing that changes for the engine as output increases is the opening of the carb throttle plate. I suspect that fuel flow is not increasing as air flow increases as the throttle opens in an attempt tp produce more watts. In this case the engine will starve. Something is limiting the fuel flow delivered by the carb.

I believe the generator controls are designed to electrically shut the generator part down in case of electrical overload rather than shutting down the engine.

[Joe]

Other than the other listed recomendations. I had a different experience with my Onan 2800. My class B did not, have a auto disconnect when van engen was running for the inverter. So, when the van motor was running and I started the gen. set. I was running to much voltage thru the system. When running vehicle motor and gen. set. I have to manually turn off circuit breaker to inverter. I did not know this nor was advised in my manual. This caused several shorts in the circutry.

[rscrogg]

I just bought a 2010 Roadtrek 210 Popular. I have the generator running fine, but I can't get the A/C to run on generator power. It works on shore power. The Roadtrek also is equipped with an inverter. Any ideas on what settings or other ways to get the A/C to work on generator?

[avanti]

Originally Posted by rscrogg

I just bought a 2010 Roadtrek 210 Popular. I have the generator running fine, but I can't get the A/C to run on generator power. It works on shore power. The Roadtrek also is equipped with an inverter. Any ideas on what settings or other ways to get the A/C to work on generator?

I think we need a bit more info to help:

What is the failure mode for the A/C? Will it run on "fan only"? Is it even getting power from the genset? Does it TRY to start but causes the generator to stall when the compressor kicks in? Or what?

[Joe]

Originally Posted by rscrogg

I just bought a 2010 Roadtrek 210 Popular. I have the generator running fine, but I can't get the A/C to run on generator power. It works on shore power. The Roadtrek also is equipped with an inverter. Any ideas on what settings or other ways to get the A/C to work on generator?

Not an expert. I would first make sure your generator is producing electrical power. Just because it is running. Does not mean it is putting out power. Then I would check breakers to be sure power if being produced is getting to AC unit. Hope this helps.

[rscrogg]

Originally Posted by avanti

I think we need a bit more info to help:

What is the failure mode for the A/C? Will it run on "fan only"? Is it even getting power from the genset? Does it TRY to start but causes the generator to stall when the compressor kicks in? Or what?

AC gets no power from the generator.

[Bob Salmi]

Originally Posted by avanti

I think we need a bit more info to help:

What is the failure mode for the A/C? Will it run on "fan only"? Is it even getting power from the genset? Does it TRY to start but causes the generator to stall when the compressor kicks in? Or what?

The generator is running, it puts out 130 volts on my Simpson 260 multimeter. The Fan will run, on the AC, even on high speed. I put an electric heater on it and it ran on 800 watts. I don't have an AMP meter. It dies immediately when you kick it on cool. (even low cool) Thanks

[avanti]

Originally Posted by rscrogg

AC gets no power from the generator.

Do other 120VAC devices get power from the generator (e.g., the Microwave, or power outlets)? As @Joe said, you need to determine whether ANY power is getting from the genset to the van. If the answer is "no", then there are two likely causes:

1) There is a master circuit breaker that is physically mounted within the generator itself. It is a little hard to find. Check the genset's manual to locate it. It is very common for this to trip somewhat randomly, causing no power to be delivered to the van.

2) You may have a transfer switch, which is a big relay that controls whether the van gets its 120VAC from shore power or the genset. It is supposed to switch automatically, but if it is busted it won't.


If you DO have power to other places, it is very likely the circuit breaker to the A/C, which will be in your main power panel.

[avanti]

Originally Posted by Bob Salmi

The generator is running, it puts out 130 volts on my Simpson 260 multimeter. The Fan will run, on the AC, even on high speed. I put an electric heater on it and it ran on 800 watts. I don't have an AMP meter. It dies immediately when you kick it on cool. (even low cool) Thanks

OK, we are discussing two different vans in the same thread.

In your case, I agree with others that your problem has to do with the genset not meeting the rather large startup current demanded by the A/C. Even if it used to work, as both devices age, the efficiency of the genset goes down and the power requirements of the A/C may go up a bit. Easiest fix is to install an EasyStart kit in the A/C, if you don't already have one. Beyond that, the only real option is an overhaul of the genset.

[Bob Salmi]

Do you know where I get one of these "east starts"? I take it they did not come with one. They have instructions? Thanks in advance, Bob

[avanti]

Originally Posted by Bob Salmi

Do you know where I get one of these "east starts"? I take it they did not come with one. They have instructions? Thanks in advance, Bob

I have no direct experience. But a quick Google search reveals that there are many options, ranging in price from a $12 capacitor to $300 RV-specific units. Maybe someone who knows will chime in about the difference.

[Bob Salmi]

I am really beginning to think that my "problem" is more on the Generator side. I probably need to take it out again and try to find some rebuild parts for the carb. I guess this is why I am retired.....

[Hondo]

You could replace the carb, don’t think they sell individual parts.

After I removed the fuel bowl on my 2800 I cleaned it and it ran much better.

If all else fails there is an Onan service center in Denver.