A/C Soft Start Question

[kjlarson]

2020 Kodiak UL 201QB: I would appreciate any experience stories and/or recommendations about installing a "soft start" mod in the A/C unit. We boondock 95% of the time and are planning to spend a good part of 2021 in the SW US where the temps get really, really hot; anything over 75 is really hot to us far north folks. The A/C unit is a Dometic that requires 1535 watts or about 127 amps per hour; don't plan on running it more than a few minutes at a time just to cool the interior. I've got plenty of battery power; 300wh available.

[dsol]

I think you will need to run the air more than a few minutes here and there. Our trailers don’t have the world’s best insulation and your trailer will likely hear up quite a bit in the afternoon, especially if over 75 degrees is hot for you.

As far as the soft start goes I have no experience but feel like I have read quite a bit about them on these pages. Were you able to do a good search and nothing came up?

Also, assume you are just trying to make sure you have enough amperage to get the air started and not trying to save when running—correct? My understanding is the soft start just helps with starting and doesn’t reduce power needs when running.

Are you using an inverter to use your batteries to run the air on 110 volts of power? I am not aware of any trailers that can run air of off batteries without some aftermarket modifications.

Good luck.

[franktafl]

The soft start option is absolutely the best way to go. The unit takes the most power when it starts up then smooths out after that.

[chily3]

You will need a generator for this to match up with AC unit with the soft start load. There are some good videos on the in the net.

[kjlarson]

I know the A/C requires a lot of amps to start the compressor and than fewer amps when running. So far have not been able to pin down the exact amps needed to start and run. As to insulation, our TT is designed for cold weather camping; when our outside temp gets into the mid-high 30's and I check the inside temp it is still in the mid 40+.

When running the A/C on shore power I can cool the TT down from the high 80's to low 70's in about 15 minutes and the TT will hold that temp for an hour+.

Thanks for the replies, this is a great forum with a lot of knowledgeable members. I've gotten answers here that neither the mfg or dealer could answer.

[ewarnerusa]

I have installed the Micro Air Soft Start kit on our 13.5 kBtu air conditioner and it works terrific. I am a big fan and highly recommend this product. Our Yamaha 2400 generator runs it no problem. I believe a Honda 2000 would also run it as this product is directly aimed at allowing this size class of generator to reliably run the typical RV 13.5 kBtu air conditioner.

You'll still want to shed any additional 120V AC items loads while operating the air conditioner. Fridge and water heater on gas (not auto), do not use other high draw items like coffee pots or microwaves.

[dsol]

@OP, are you trying to avoid a generator altogether and just use your batteries with an inverter or just trying to reduce the start up load on the generator?

Personally, I would opt for the soft start and a generator like the Honda 2000. You will have some noise but will be safest for all weather.

[BertF]

I installed a Micro Air soft start on our 13.5K AC and I can run it with no problems off a 2000 Watt inverter generator (Wen).
In my opinion, soft start is the only way to go.

[wiresLV]

I have the Micro Air Easy Start installed on an Atwood 15K AC/heat pump.

I have 600AH of 12V batteries into a Magnum MSH3012 3000W inverter.
The Atwood will start and run off the inverter without lighting the inverter's overload indicator. The inverter will draw around 150 DC Amps steady while the the Atwood is operating. I can run the AC about 1.5 hours before I'm down to 50% battery capacity (assuming no generator or solar input and no other significant loads). I did this a couple times for testing but it's not a regular occurrence.

If you're planning on only using batteries to run the AC, my suggestion is plan on a heavy duty name brand inverter, a large battery bank, and heavy gauge cables in between. The MSH3012 I'm using is built like a tank and it's connected to high-end Lifeline AGM batteries with a short run of 4/0 cables. Even then I don't like to run the AC on it. Things get hot and it's hard on the inverter. If I was going to build a system with frequent AC use in mind it would be 24 Volt based to reduce the DC current requirements.

-John

[TK on the road]

Another question- can I use the 30 amp plug in the Honda 2200 “companion” and the soft start? I know I don’t have 30 amps unless I run parallel with another 2200 - correct?
Thank you for your help
Be Well

[dsol]

I believe the outlet will work but you will only have 13 or so amps. Not positive though.

[aguablanco]

I live in the southwest, Phoenix to be exact, and if 75* is hot to you this is not the place to visit in the summer unless you are above 6000'. At 105* my AC unit will only get the trailer to ~85*. That's on a good day. The other thing you will need is shade. That is something else you can find at elevation. Summer is the time of year when we Arizonans get out of town and head for the high country. This place, much like your home in the winter, takes quite a bit of acclimation that can only happen over time.

RichH