Shutting Off My Converter to Start AC w/ Generator???

GordonThree wrote:

bowler1 wrote:
Interesting point on the load prior to switching over. I had not considered that at all. The Yamaha does not give the capability to switch off the Eco-mode like on the Hondas, so it is running at low throttle when no load is applied. I agree it would be helpful if it were running at a higher throttle to start with.

What Yamaha do you have? My Yamaha 2000 has an eco on/off switch.

All generators throttle up/down depending on load, regardless of whether they have eco or not.

I think what people mean is that Eco mode lowers both throttle AND rpms.
All generators throttle up and down under load is true, but only those with Eco mode will change rpms.....and those must be inverter models that convert 12v to AC. 1800 rpm diesels and 3600 rpm non inverter gas gens will throttle up and down the actual throttle blade of the carb (yeah yeah diesels) but the rpms stay constant to keep the correct voltage/waveform.

I put the refrigerator and water heater on propane, unplug the converter at the converter, and put the AC fan to on. I have a Yamaha EF2400iS and get a dependable AC start at an altitude of 4200 feet.

smkettner wrote:
Same goes for elevation.

Good point here - generators have so little spare horsepower they really lose capacity as you climb above sea level. My Yamaha 2000 could not sustain more than 1300 watts continuous (down from 1600w cont.) at 6500 ft.

Turn all breakers OFF. Except the Main and Air Conditioner. Then give it a go.

If blower fan and compressor start together you can also try putting the blower fan on before you drop the thermostat to call for the compressor. But this is really marginal if needed. If it works on a cool day it may not on a hot day when really needed. Same goes for elevation.

bowler1 wrote:
Hi,
This is a follow up to my post from yesterday about starting AC with a generator--thanks so much for all the help!

Seems that the next thing I need to try is to ensure my converter is shut off prior to trying to start the AC.

Can anyone tell me how to do that? I assume there will be a breaker in the circuit box that should allow me to do that. I don't have my RV here at home so I will have to check it out next time I head out to where it is stored.

thanks
Matt

It will be tied to one of the breakers, on both of the TT's I have owned it has been one of the general breakers.

Start the generator and turn on a few lights, then start flipping breakers. When the lights dim you found the breaker you need to turn off.

If it's not a separate breaker it's easy to make it separate, or add a 15A switch inline for easier shutoff.

Artum Snowbird wrote:
Yes, your converter is just another load and will be labelled on the breaker box. If you look at it, many converters are capable of putting out 45 amps at 12 volts. That works out to 540 watts if it's working hard trying to charge low batteries. Not often it would be running that busily, but it is a sizable sum.

There is quite a bit of power loss when converting, so the draw will be larger than 540 watts, and the voltage is higher than 12 so the watts are also higher. Output is probably closer to 610-650 depending on charge voltage.

My 55A converter output is up to 800w, but draws up to 950w.

The 45A version of my converter draws up to 750w, other 45A converters will be similar.

RoyB wrote:
Cutting off your converter will also kill your 12VDC inside your trailer so those items will have to run from your charged up connected battery. You will need some 12VDC power to keep a few things running inside the trailer... Ceiling lights is one item you will probably want to have working which only runs from 12VDC coming from the Converter or the Battery.

One other thing I would do if the batteries needed a charge and I needed A/C was let the batteries charge for a 20-30 minutes and then start the A/C this really lowered the load from the converter.

RoyB wrote:
If my roof air conditioner ever needs replaced I will get a 9,500 BTU size replacement roof mounted unit. Those will work just fine with the 2KW Honda EU2000i generator as well. We don't use the A/C all that much in our OFF-ROAD POPUP setup anyway as most of the time we are sitting in well shaded woods camp site anyway. FANS work great in there for us...

Roy Ken

I had a 9K BTU A/C in my 18CK and I didn't have to turn the converter off to start the A/C until I went from 1 12V G24 to a pair of 6V, even if the 6V where at a 80% SOC (normal for summer camping when the A/C is used) the converter was drawing too much to run both.

If this was going to be a habit, why not just chop the black wire to the converter infeed, and bring both ends to a wall switch, and label it "converter"

Cutting off your converter will also kill your 12VDC inside your trailer so those items will have to run from your charged up connected battery. You will need some 12VDC power to keep a few things running inside the trailer... Ceiling lights is one item you will probably want to have working which only runs from 12VDC coming from the Converter or the Battery.

I have played the game of powering down everything I could to get my EU2000i Honda to start my air conditioner. I Usually can get it started with everything else turned off and playing games with running the A/C fan first etc but as soon as it cycles on/off after getting things cooler inside it dies on me when it wants to start up again.

The on-board converter/charger unit is usually the first 15AMP circuit breaker just below the MAIN 30AMP breaker in the 120VAC Circuit Breaker Panel...

We would bring along a 8000BTU Home Window unit with us if this was an extended stay camping off the power grid. My 2KW Honda runs this air conditioner just fine. The regular trailer with hard walls will not support a permanent mount in the window but after you setup it would work out ok. We just sit the a/c in the floor of our POPUP trailer when in transport mode. and place it in the unused tent bed area sticking out the side window flap. Worked good for us cooling things down a bit running off the generator.

If my roof air conditioner ever needs replaced I will get a 9,500 BTU size replacement roof mounted unit. Those will work just fine with the 2KW Honda EU2000i generator as well. We don't use the A/C all that much in our OFF-ROAD POPUP setup anyway as most of the time we are sitting in well shaded woods camp site anyway. FANS work great in there for us...

Roy Ken

bowler1 wrote:
Interesting point on the load prior to switching over. I had not considered that at all. The Yamaha does not give the capability to switch off the Eco-mode like on the Hondas, so it is running at low throttle when no load is applied. I agree it would be helpful if it were running at a higher throttle to start with.

What Yamaha do you have? My Yamaha 2000 has an eco on/off switch.

All generators throttle up/down depending on load, regardless of whether they have eco or not.

Interesting point on the load prior to switching over. I had not considered that at all. The Yamaha does not give the capability to switch off the Eco-mode like on the Hondas, so it is running at low throttle when no load is applied. I agree it would be helpful if it were running at a higher throttle to start with.

I will have to experiment with that.

Is that why some people say to run the fan for three minutes or so prior to trying to start up the AC?

Yes, your converter is just another load and will be labelled on the breaker box. If you look at it, many converters are capable of putting out 45 amps at 12 volts. That works out to 540 watts if it's working hard trying to charge low batteries. Not often it would be running that busily, but it is a sizable sum.

Would it help to have as much load on the generator as you can, then suddenly switch it all off, and turn on the air conditioner before the generator has a chance to throttle down? I know, if I have my genny runny on eco mode and then add a big load it stumbles. But if I have it running on normal, I hardly notice the difference. Try adding a small heater just before you switch.