What Is a Soft Start for an RV AC, and Is It Worth It?
A soft start for an RV AC helps the compressor start with a gradual power ramp, which can lower the initial electrical surge. It may help when you have limited power, but it doesn't make every air conditioner compatible with every generator or hookup.
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A soft start for an RV AC ramps up power to the compressor gradually, which can reduce the high current surge at startup. It may help when you're using a smaller generator or sharing a limited hookup, but it won't reduce every electrical load or guarantee compatibility.
The main question is whether your power source struggles at the moment the compressor starts. If it does, check your AC's requirements, the other loads you run, and whether the soft-start kit fits your unit.
What is a soft start for an RV AC?
An RV AC soft start is an electrical device that changes how the compressor starts. Instead of drawing a sharp burst of power at once, the device ramps up the compressor's power draw.
Air conditioners can need much more current for a brief moment at startup than they use while running. Reducing that initial surge may make startup easier for a generator or campground circuit with limited capacity.
A soft start doesn't create more power or change your RV's service rating. For a broader look at electrical loads, see how many amps an RV uses.
How does an RV AC soft start work?
A soft start controls the compressor's startup sequence so its demand rises more gradually. The goal is to reduce the initial inrush current, which can trip a breaker or strain a small generator.
The exact design varies by kit. Some use a ramp-up process, while others also include features such as short-cycle protection or fault detection.
That startup help is different from an energy source. A soft start won't supply power to the AC when the generator, battery system, or hookup can't provide enough for continued operation.
When is a soft start worth it?
A soft start may be worth considering if your AC struggles to start on a power source you otherwise expect to use. It can also help if startup noise or compressor vibration is a concern, depending on the kit and AC.
Before buying one, check:
- Your AC make, model, and capacity.
- The generator's output and the AC manufacturer's guidance.
- What else will run at the same time, such as a microwave or water heater.
- Whether the kit is made for your AC and fits its installation space.
A soft start isn't a fix for every power problem. If the AC won't run after startup, the running load may exceed the source's capacity; reducing startup current doesn't solve that.
Can a soft start run an RV AC on a smaller generator?
It may help an AC start on a smaller generator, but compatibility depends on the specific generator, air conditioner, and other loads. A kit's advertised support for a generator size isn't a guarantee for every RV setup.
The SoftStartRV kit is described as supporting use with a 2200W generator and AC units up to 15,000 BTU. The Micro-Air EasyStart Breeze 399 is described for most rooftop AC models up to 18,000 BTU and includes a stated 75% inrush reduction.
Check your AC manual and generator guidance before relying on either setup. For help understanding what your AC draws, read how many amps an RV AC uses.
Does a soft start make an RV AC battery-ready?
A soft start doesn't supply battery power or replace an inverter. It addresses the compressor's startup demand, while the battery system and inverter must still provide enough power for the AC to run.
If you're planning to cool your RV without a hookup, first check the battery capacity, inverter size, and AC's running demand. Our guide to running an RV AC on battery power explains the rest of that setup.
What does a soft start not do?
A soft start doesn't make a 30-amp RV into a 50-amp RV, increase a generator's rated output, or guarantee that multiple appliances can run at once. It also doesn't eliminate the AC's normal power use after the compressor starts.
If a breaker trips, the cause may involve the total load, wiring, a weak supply, or another problem. A soft start may help with compressor startup, but repeated trips deserve a closer check; see why an RV surge protector keeps tripping for common power-supply issues.
What should you check before choosing a kit?
Choose a kit based on your AC model, installation needs, and power goal. A feature such as a high inrush-reduction claim matters only if the kit fits your unit and addresses the problem you have.
The MACH Coleman Soft Start Kit 1497-3601 is made for Coleman-Mach Series 45000, 47000, and 48000 air conditioners. It is described as reducing startup amperage by up to 75%, with installation from outside the coach.
For other AC models, compare the stated compatibility and installation instructions before choosing a kit. The SoftStartRV Soft Start review goes into one option in more detail.
Who should consider a soft start?
Consider one if compressor startup is the limit on your power setup and the kit is compatible with your AC. If the AC already starts reliably and you have enough power for your usual loads, the benefit may be small.
Don't choose by generator wattage claims alone. Confirm the unit's requirements and account for other appliances you expect to run.
Is an RV AC soft start worth it?
An RV AC soft start may be worth it when you need to reduce startup demand, especially when using a smaller generator or limited hookup. It won't add power or reduce the AC's ongoing load, so compatibility and the rest of your electrical setup still decide what will work.
Pick a kit made for your exact AC, then check whether its installation method suits you. If you're still planning around total demand, start with how many amps an RV uses and compare that with your available power.
Frequently asked questions
What does a soft start do for an RV air conditioner?
A soft start ramps up power to the air conditioner's compressor at startup, which can reduce the initial current surge. That may make starting easier on a limited power source, but it doesn't lower the air conditioner's normal running demand or guarantee that a particular generator or campsite hookup can run it.
Will a soft start let an RV AC run on a smaller generator?
It may help an air conditioner start on a smaller generator by reducing startup demand, but the result depends on the AC, generator, and other loads running at the same time. Check the AC and generator guidance, and avoid assuming that a soft start makes every 2200W generator compatible.
Does a soft start reduce RV AC running amps?
A soft start mainly changes the startup ramp, when compressor demand can briefly be high. It doesn't mean the AC will use less power throughout a cooling cycle, so plan around the unit's running load and the power source's capacity.
Can I install an RV AC soft start myself?
Some kits are designed for DIY installation and include wiring guides or video support, but the work involves an air conditioner and electrical connections. Check the instructions for your exact AC, disconnect power as directed, and use a qualified RV technician if you aren't comfortable with the job.
