With improvements in RV solar charging systems and increased availability of portable generators, RVers are no longer limited by campground availability. But when you aren’t plugged into a shore power pedestal (and even sometimes when you are), you may not have sufficient power to start your air conditioner. That’s where an RV air conditioner soft start makes a huge difference.
Some manufacturers now install soft starts in their air conditioning units at the factory. If your camper doesn’t have one, adding this RV AC upgrade can improve your ability to start your AC when generator or shore power is insufficient. Let’s explore how an AC soft start works, why you might need one, and how to install one in your RV.
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ToggleWhat Is A Soft Start for an RV Air Conditioner?

A soft start is a device installed in your air conditioner to reduce start-up power requirements. They are typically mounted inside the roof-mounted unit under the A/C shroud, but some also plug into the shore power pedestal.
How Does an RV AC Soft Start Work?

An RV air conditioner soft start is installed in line with the compressor that powers your air conditioner. This device limits the compressor’s initial power surge. Instead, it slowly pushes power to the motor until enough is achieved for startup. Without a soft start, a large surge of power is sent simultaneously, causing more strain on the camper’s electrical system. An AC soft start is nearly essential if you want to create a system that allows solar powered AC for your RV.
Every RV air conditioner has two important power ratings: starting and running. The starting requirements are how much power the unit needs to power on, and the running requirements are how much power it needs to stay running.
The starting requirements are much higher than the running requirements. A lower starting power requirement makes it easier to power up, putting less strain on your electrical system and reducing wear and tear on the compressor. These requirements are listed as “watts” or “amps.” Using an online calculator, you can easily convert watts to amps or amps to watts if needed.
Why You Need an RV AC Soft Start

There are many benefits of using a soft start on your RV’s air conditioner and a few reasons not to. Let’s take a closer look at these below.
Off-Grid Use
One reason to add a soft start to your AC is because you like camping off-grid using a generator. Generators allow you to explore more and avoid crowded campgrounds.
The problem with running your air conditioner off generator power is the large amount of power these air conditioners require during start-up. At the minimum, you’d need a 3,500-watt generator to power one 13,500-BTU RV air conditioner. In cases where you have a 15,000-BTU unit or multiple air conditioners, the generator sizing can double. The more power your generator offers, the more expensive and physically larger it will be.
Adding an aircon soft starter can reduce your air conditioner’s starting power requirements by up to 70%, allowing you to use a much more cost-effective and physically smaller generator.
Technician Tip: As the industry changes rapidly, watch for DC air conditioners and digital A/Cs that run on inverter power (from your batteries). A soft start is often required for these units and is typically installed at the supply side near the battery bank.
Start-Up Noise
If you’re a light sleeper, you’ve probably been awoken by the air conditioner booting up in the middle of the night. This is especially true if you have an AC unit directly above your bed. A soft start reduces the noise an air conditioner makes during start-up, allowing you to sleep more peacefully.
Technician Tip: A soft start won’t reduce a unit’s noise level while running.
Wear and Tear
By limiting voltage spikes to the compressor during start-up, an RV AC soft start reduces wear and tear on your cooling system over time. The less wear and tear you have, the more reliable it will be and the longer it will last. In other words, a soft start can save you money by extending the life of your system and reducing the frequency of replacements.
Shore Power
A soft start isn’t exclusively for generator use; you’ll also benefit from using one at the campground or when plugging into power at home. For example, if you have a camper with multiple air conditioners and the park only offers a 30 amp service, you may not be able to run both units due to the high start-up demands.
However, with a soft start, you’ll reduce the total starting requirements, increasing your chances of powering both units simultaneously. When camping at a metered location where you pay for electricity separately from your site rental, an AC soft start eliminates surges to the grid power system that drive up your electric bill.
Technician Tip: A soft start is installed onto a single air conditioner; if you have multiple, you must purchase a separate soft start for each one.
Downsides of Using an RV Air Conditioner Soft Start
If you’re wondering about the downsides of using a soft start for your air conditioner, there aren’t many. However, they can be expensive, and if hardwired into your air conditioner, they may require professional installation, which is another expense. It’s also important to add that they won’t necessarily reduce your overall power demands, so don’t expect much savings here.
Is a Soft Start for RV AC Worth It?
Although admission is expensive—most range from $200 to $400—a soft start is worth it for off-grid campers using a generator or those with multiple air conditioning units. If you only stay at campgrounds with dedicated 50-amp service, you might not find as much value in a soft start air conditioner. For everyone else, they are absolutely worth the money.
How To Install a Soft Start for an RV Air Conditioner

Although an AC soft start kit can plug into the shore power pedestal, most must be wired into the air conditioner. To hardwire your AC soft start, you’ll need a few tools. Let’s review these below.
- Screwdriver (Hardware varies by manufacturer)
- Wire Strippers
- Wire Crimper
- Electric Tape
- Test Light or Multimeter
Once you have the correct tools, you can begin installation.
Technician Tip: Always refer to the installation instructions for specific steps and wiring instructions. If you don’t feel comfortable completing the installation yourself, contact one of our local service centers.
You can use these general tips and practices for most installations.
- Turn off the breaker and unplug shore power.
- Ascend to the RV roof and remove the air conditioner shroud.
- Identify and locate the compressor and start capacitor (cover panels may need to be removed to access these components).
- Locate the air conditioner’s model number and obtain the wiring diagram from the soft start manufacturer.
- Attach wires from the soft start to the compressor and start capacitor.
- Use electrical tape to seal all connections.
- Mount the soft start inside the overhead unit with the connector facing down, clear of other components.
- Reinstall cover panels and overhead shroud.
- Apply power to the breaker.
- Check for proper operation.
Technician Safety Tips
Use this safety advice from our expert technical service team to stay safe during this installation.
- Discharge the existing start/run capacitors before installing to reduce the chances of electric shock.
- Never work on high voltage alone.
- Utilize fall protection anytime you are working on elevated surfaces.
- Consider insulated tools or dielectric gloves to reduce the risk of electrical shock.
- Check for insect nests before removing the A/C shroud.
At the end of the day, it all comes down to how you use your RV. If you boondock or have an RV with multiple large air conditioners, an AC soft start can dramatically increase where you can camp and how comfortable you can keep your RV’s climate during your stay!
Let us know in the comments below if you have a soft start kit and how you like it.
Author
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Conner Lund is a Technical Content Writer. He has both hands-on experience and real-world knowledge. He’s an avid outdoorsman: camping, hiking, backpacking, mountain biking, kayaking, hunting, and fishing are all things he enjoys that you could find him doing on any given weekend. He loves to travel and see new places. He does most of his exploring and camping out of his overlanding truck with a rooftop tent.
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Where does one find a person to install this. We want to add a second AC unit but am told we will have to plug in a separate 110 volt outlet / extension cord to it. So this would require running a channel from the roof down the side or down the steps from the roof. Any guidance on whether this would allow me to use the existing wiring (RV is 30 amp class c )
Hi Stuart!
I’d recommend reaching out to our Performance and Improvements department. You can request an appointment here: https://rv.campingworld.com/rv-performance-improvements
Hope that helps!
My purpose in installing the SoftStartRV unit on my Grand Design 17MKE travel trailer Furrion A/C was to allow me to use a smaller, lighter weight generator (Westinghouse iGen2800c) to run my 14.5K BTU A/C. After installing the soft start, I was pleased with the result, BUT, I did find some caveats. In order to be able to run my A/C, I did find that it can sometimes be necessary to turn OFF other systems in order to minimize the load on my generator. In particular, I turned off the breaker for my “Converter” in my electrical panel because running the converter can suck additional power from the generator causing it to shut down due to overload. Also, don’t run the microwave while using the A/C. You may need to experiment to find the best setup. But good A/C on a hot day is worth the effort.
One more thing. My iGen2800c comes with a carbon monoxide safety system. I once had positioned my generator near another generator, but I found that arrangement often shut my generator down because it was detecting the CO from the “other” generator. Be careful about putting two generators too close together.
This is great experience. Thanks so much for sharing!
I’ve also heard of a slow start which plugs into the main power supply at the park and eliminates the need to install on each ac. Don’t know if Camping World sells it.
Hi Barry!
You are correct in that these exist. They actually appear similar to plug-in surge protectors, but are a different tool. They aren’t considered as effective for individual appliances as built-in soft starts, however.
Furrion AC units don’t work with soft-start kits. If you put one on a Furrion AC it voids the warranty.
According to Furrion, it does not need it. I have not looked at the amp draw of my Chill 14.5kbtu units, but both units run with no issues on my 5500 watt generator.
Hi Stuart!
Some newer A/C designs incorporate the soft start feature. The manufacturer should always be consulted prior to making any modification to ensure compatibility and that safety issues are considered. Any RV with 3 A/Cs probably incorporates a priority share switch system as well, so that the overall RV electrical system isn’t overloaded. The manufacturer is able to inform you of such features that have been built in at the factory. In addition, some manufacturers make soft start kits specifically for their own products. These can be installed without any worries.
Let us know if you have any other questions!