Soft Starter for Air Conditioners & Heat Pumps – Reduces Startup Surge, Reverse Motor Protection, Easy DIY Install, Generator/Stored Energy/Solar Compatible (16–32A)

This soft start device is a game changer. We have a Goodman 5-ton condenser that starts each time with a loud, but normal, "thump" as the compressor gets hit with 130A start-up current. Residential condensers work this way by design since it requires the least amount of parts (simple contactor and run capacitor) and is therefore cheaper to manufacture. All of this is fine if your AC unit is located far enough away from your living space that the start up noise is not bothersome. Unfortunately, like most homes, our AC unit is installed on the side of our 3,000 sq. ft. house and you can hear the condenser start from most rooms. A good amount of the start up noise is amplified by the refrigerant lines that enter the house, go up the wall, and then over the attic space to the furnace/AC unit in the middle of the house. I have tried condenser mounting pads on the slab and an additional support bracket for the large refrigerant line but nothing has reduced the reverberating "thump" noise at start up. My research into this issue showed that people generally try to solve one of two problems with their AC units: "not enough" start problems and "too much" start problems. The "not enough" start camp winds up installing hard start capacitors to give the compressor an extra jolt so that it starts up reliably. This can be useful for older compressors or for units where the owner hasn't diagnosed other faults such as a worn out start/run capacitor. The other camp searches for ways to reduce the "too much" start problem that causes high current draw (a problem for generator/solar power sources), noise, and wear-and-tear on the compressor that I mentioned earlier. Which brings us to the electronic soft starter. This device is specifically designed to control the compressor in-rush current at start up and thereby reduce high power inrush, unnecessary noise, and wear on the compressor motor. It gradually accelerates the motor up to speed instead of hitting it with full current all at once. It's like accelerating in your car by gradually pressing the accelerator as opposed to slamming down the pedal and going full throttle from every stop. Both get you where you want to go but only one method does so without unnecessary power consumption, noise, and wear-and-tear. Installation of the AIRGO device is very straightforward for the technically-inclined and for those familiar with AC condenser components. The kit includes all the additional wires you need with pre-crimped terminations that makes installation in a standard AC unit easy. It turns out that the AIRGO unit is identical to the Eltwin soft starter (also sold here) but has different branding and, frankly, a much easier to understand connection diagram. I did create my own connection diagram (see photos) so that I could fully understand the connections as they related to my system (I also replaced the contactor and run capacitor at the same time). NOTE REGARDING WIRING: It doesn't matter if you have a single pole or double pole contactor. You can use either type per AIRGO with no wiring differences whatsoever. I did find (on Eltwin's soft starter website, btw) a schematic showing the soft starter "ACTIVE (T)" wire connected to the switching pole of the single pole contactor and the "COMMON" wire connected to the pass-through pole. Again, it makes no difference which pole is used but I wired it per the Eltwin schematic anyway. This is shown in the photo attached. Once connected, everything worked perfectly and exceeded my modest expectations. The AIRGO soft starter has COMPLETELY ELIMINATED THE START-UP "THUMP" NOISE from the compressor. It's totally gone. When standing next to the condenser, the ONLY start up sounds are the simple click of the contactor and then a slow whooshing sound as the compressor and fan come up to speed in less than 2 seconds. Inside the house, the only way we know that the condenser has turned on is when the interior HVAC fan powers up. No more jolt, no more “thump” —completely gone. In summary, the AIRGO soft starter delivers everything it promises and is worth every penny to restore peace and quiet to your AC condenser start-up. The AIRGO (aka Eltwin) soft starter device appears to have been around for at least 10 years which speaks well of its ongoing value and overall reliability. I expect the device has been refined to the point that it will deliver years of service when properly sized for your system and installed correctly. I only wish I had discovered this device years ago! Oh well, if you install one, you'll quickly forget the few extra dollars you spent on this quality device. For me, it paid for itself on the first start up. Thank you, AIRGO!

The cool thing about this soft start is that it comes with the cell phone number of company owner and master electrician, Bob. While the included instructions were clear for an AC that has a single capacitor, my AC condenser unit has 2 capacitors instead of 1. I gave Bob a call and he walked me through installing the soft start over the phone in less than 10 minutes. I installed this on my Trane 4 ton AC with an LRA of 117. While my multimeter does not have inrush reading capability, I did test max starting amps before and after installing this soft start. Before installation, I was getting a reading of 95.2 starting amps. After installation, starting amps dropped to 25.3, which allowed my Westinghouse WGEN11500tfc generator to run my AC, along with everything else in my house. There are other well-reviewed soft starts on the market but they're selling at a much higher price. I'm guessing if you're reading this review, you are in a similar situation as I was in. I can tell you that this product does what it's supposed to do, is less expensive, and has great support that makes it easy to install.

This unit works great and is much less expensive than some other alternatives. But the instructions leave a lot to be desired. Reviews here tell the story. Many people are confused about the wiring or needed assistance from Bob. Bob should update his instructions! The main reason for the confusion is that the AirGo really only has four connections even though it has five wires! The instructions do not make it clear that two of the five wires are really the same thing. The terminal labeled “Run Capacitor” (brown wire) is actually connected to the terminal labeled “Active” (red wire) inside the AirGo. It would have been far better to produce this unit as a 4 wire device (like the competitors) and make it clear in the instructions that the same contactor terminal that goes to the “active” terminal should also be wired to the common terminal of the run capacitor. So you find reviews here that insist you must remove any existing connection between the contactor and the capacitor common terminal even though it doesn't hurt anything since it is actually a redundant connection (assuming everything else is connected correctly). Other reviewers followed the instructions exactly and did not remove the existing wire. Of course they are both right. The only clue that the brown and red wires are the same thing does not come from the instructions but at the very tail end of the video in the listing. And even there, it does not actually state that those two terminals on the AirGo are actually connected together internally. Once I got my unit and verified the internal connection, I dispensed with the brown wire and wired it as a four wire unit. Very simple. The attached diagrams show the before and after connections for my unit – a 5 ton Carrier two-stage unit with a dual element capacitor. Note that the brown wire was unnecessary because of the existing (yellow) wire between my contactor terminal 23 and the common terminal of the capacitor. Like others, I had to supply my own eyelet connector for the active wire to be properly connected to my contactor since an eyelet is not included. Note: Like many units with a compressor crankcase heater, this unit is wired such that the crankcase heater (CH on the diagram) is wired across the contactor. The heater can only be energized when the contactor is off. But the heater current path actually went through the run winding of the compressor (in parallel with the run winding of the fan motor). But now that the compressor run winding is wired to the AirGo unit not directly back to L2, I was concerned that the current might try to flow through the AirGo and possible do damage to any solid state devices inside. My assumption is that the fan motor run winding will provide a sufficiently low path of resistance to prevent any significant current from going through the AirGo. The 40W crankcase heater draws about 0.16 Amps.. Because it is summer now and the heater is never on, I will have to wait and see if my assumption is correct.

Ignore the missing screw. Supposedly when we bought the house the compressor was looked at and the blower. But upon installing the soft starter the capacitor was ancient and when checked with dmm was below spec. Didn’t take an install pic since it was hot af outside and install took me 30 mins. Anyways, the soft starter was easy to install. Hardest part was using a screw driver to install wires and self tap screws for mount to compressor. I didn’t use an 8AWG O-clamp and just screwed the supplied precrimped wire to where it needed to be. Lights no longer flicker when compressor comes on. I forgot to take a video on it before but essentially it’s just without the delay and now it’s not as loud as it used to be upon initial startup. 15/10 would install again! Lastly I installed this for the above but also since I have a generator hookup and am looking forward to the next power out. Hopefully, the power boost can power the whole house but in the event it doesn’t then at least a generator won’t dump a bunch of amps when the A/C starts. I do have a home surge protector installed as well but that’s for my delicate electronics that I’ve learned the hard way of not having costs to replace. lol

My Local AC company wanted to charge over $500 to install soft start because they notice my contactor has slight discoloration (and they want to charge ~$400 to replace the contactor). I purchase the contactor from Amazon with way much lower cost and replace it mysel. I was debating between the this AirGo product vs other brand and decided to go with AirGo. First when reaching out with product enquiry, AirGo is the only company that respond quickly and they also immediately provided Bob cell's phone number. I did not call Bob at this time since I was looking for simpler info. Once I received the products, I did called Bob for assistance and surprise to hear Bob on the other end because typically with any company when they give phone number it will be a group of technical support. Bob was great in giving instruction on my wiring on which color of wire need to go to which terminal. At the end of the day I was able to successfully install the unit with no issue. The main reason I was calling Bob is because my wiring color is slightly different than the provided instruction. I notice when the AC start my light no longer flicker than it used to. I am unable to tell the current reduction because I do not have the best meter and and am only able to capture running current and not max current. Hoping this will not have any issue with the my heat pump during the winter time and will post update (if any issue) Other than that overall has been great experience, unit is easy to install, great customer support and excellent technical support. If you are reading this and still have doubt, I would highly recommended to get this product.

I'm pleasantly surprised at how well this works. It was simple to install. Wire and terminals were included. It reduced the inrush current on my 5 ton heat pump by 63.8%. From 158 amps to 57 amps.

While the AIRGO 16-32A soft starter performed well initially, the product’s longevity is questionable and unacceptable. It did work initially as intended by reducing startup surges while functional. However, this unit died completely after just 21 months (about 1.5 summer seasons of use), which failed just outside the standard 1-year manufacturer warranty period. After opening the case to inspect for a basic fix, the internal fuse was intact and there were no visible PCB burns. This indicates a deeper, hidden component failure that would be cost prohibitive to fix it. For a premium-priced soft starter, the overall quality and reliability are severely lacking. I cannot recommend a $250 device that fails in less than two years. Buyers should beware of the short lifespan and lack of manufacturer support after the first year. I'd look elsewhere for a quality AC Soft Starter to avoid the headache later.

If you have not pulled the trigger on this soft start yet, just do it. You will not be disappointed. First, the kit is made with excellent quality and comes perfect with all required cabling. The connections are easy with only simple tools required. The instructions are abundantly clear and are easy to follow. The best part is that each kit comes with a business card that has info on how to reach Bob (owner and Master Electrician). I am an extra cautious person so I had a question about how this soft starter works on my A/C condenser before I dove in. I had the pleasure of speaking with Bob, and he quickly provided clarity. The best part is that I ended up bothering him again as I was in a bit of a self induced bind late in the evening and much to my surprise, he got back to me right away to clear up my own user error. Thank you Bob!! All is not lost in the world of good products and customer service.