1/2HP Single Phase VFD

I have a 4 ton heat pump that was too powerful for some of my loads. This VFD reduced the frequency of my heat pump to lower its capacity to about a 2.7 ton unit. All my loads are happy now. Technical support was great in helping with my setup. This VFD has a wide range of capabilities. I just needed a frequency reduction. An added benefit was the soft start of my heat pump. I can also monitor the amperage of my heat pump.

Good instructions on how to set basic parameters. Bad is they don't have live tech support after purchase, only email option, not great when in the field trying to finalize install. I would say if you have a decent amount of experience with vfd and you have a basic application, these drives can definitely save you or customer some money.

May 19, 2025 Amended ReviewI received a message from ATO Technical Support after having sent to them via separate correspondance a more detailed description of the wiring configuration I had used. Specifically, I connected a 500 Watt 100 Ohm braking resistor onto the bus connected to the P+ and P- terminals on the main bus connector strip (these terminals are painted red and are adjacent on the bus). ATO Technical Support in their May 19, 2025 correspondance to me indicated I should have connected the braking resistor to the PB and P+ terminals, not the P+ and P- terminals. Connecting the braking resistor to the P+ and P- terminals overloaded the driver circuit which caused the main board components to thermally fail. So, ultimately, it was my own fault for the failure.However, the fact remains that the manual that came packaged with the unit I received made no mention of incorporating a braking resistor, but that this manual is an abridged version of the more comprehensive manual that can be downloaded via QR code in the supplied abridged manual. That more comprehensive downloaded manual also lacks any wiring instruction for a braking resistor although it does reference parameter changes required if a braking resistor is to be installed.I used a different manual I had downloaded for ATO GK3000 series Variable Frequency Drives for slightly different models in the series where braking resistors were described and their specifications for various capacity drives were supplied. A diagram in that manual did show the proper terminals for installing a braking resistor as terminals PB and P+.Inspection of the photos I attached to my original review show that the PB terminal is at the extreme left end of the bus strip with the P+ terminal near the middle, and that the P- terminal is adjacent to the P+. The similar color coding and proximity of the P+ and P- terminals was a factor in my wiring mistake.ATO Technical Support did indicate that further updates to their instructions for GK3000-1S (single phase) series drives would include detailed and unambiguous requirements for incorporating braking resistors.Accordingly, I have changed my review of this purchase from a 1 star to a 3 star. I did so because it ultimately was my fault for mis-wiring the resistor. However, given that the instructions in the ATO manuals were confusing and partially contradictory doesn't entirely exonerate their culpability in this matter. I am hopeful that ATO will improve the instructions they provide their customers.May 14, 2025 Amended Review:After discussing the situation with an Amazon representative via Chat, I have been allowed to return this item in exchange for a full refund. I am grateful to Amazon for providing this service despite the item being outside of the return window. Amazon remains the best source for these kind of purchases. I can't recommend Amazon highly enough.Original ReviewI purchased this 3hp 220V Single Phase Variable Frequency Drive Model ATO GK3000-1S0022 to enable reduction of the spped of my table saw motor so that sanding operations using a 10" diameter aluminum sanding disk would not be as aggrerssive as occurs when the disk is at full speed. The table saw motor is 2hp 220V Single Phase. I downloaded the comprehensive manual as well as the setup guide as referenced by the QR codes contained in the information enclosed with the VFD. After reading this information I adjusted the VFD parameters per the instructions. I plugged the table saw into the 220V power cord I made up for the VFD and the table saw motor successfully started and ran with the only load being the inertia of the sanding disk. I conducted several start and stop cycles on the table saw and exercised varying the speed of the table saw motor between 60% and 100% of rated rpm with great success. I repeated this sequence the next day successfully with the only load on the table saw motor being the inertia of the sanding disk. I then unplugged the VFD from its 220V power supply and I unplugged the table saw. I didn't use the table saw for any purpose for another month. When a need arose to use the sanding disk on the table saw after the month had passed I plugged the VFD into the same 220V supply that I had used the month prior. The table saw was not yet plugged into the VFD and so only the VFD was connected. I noticed that the display on the VFD wasn't lighting up and then smoke started to emerge from the vents on the VFD cover. I immediately disconnected power to the VFD and allowed it to cool off. I removed the VFD cover and noticed burned components on the control board. The attached photographs show the complete control board and a blow up of the region containing the burned out components. At no time was this VFD ever used for useful work, only setup exercises, and the only load it was subjected to was the inertia of the aluminum table saw sanding disk. I missed the return window on this very expensive item by 7 days, and so I'm out $378 for something that never did any useful work. I had purchased a LaPond VFD for my 3hp 14" bandsaw 6 years ago and it has performed flawlessly, and so I felt emboldened to try this ATO unit on my table saw. That was a serious and expensive mistake.

The media could not be loaded. I have a single phase jointer/combo machine that came with a 60hz frequency cycle however, my country's electricity system runs on a 50hz cycle. So I got this device to rectify this issue. As soon as I got the device I made the necessary wire connections and attempted to power on the device and the machine. Afterwards, I noticed that I was not getting anything from the output terminals. So I removed all the wiring and did some troubleshooting on the VFD and let me tell you, the readings were waaaay off. The readings (see the attached video and images) are way higher than those that product video number 4 stipulated.for example, the stipulated readings for the lower bridge for the inverter circuit should about 0.4v while the readings I actually got falls between 26 and 27v!... I am extremely disappointed especially due to the fact that I paid over $1000 for this item. TO PUT IT simple : I NEED A FULL REFUND! And when I contacted customer services for this item the response was very poor and unsympathetic. Overall a very bad experience on all sides!

I like the design. Very programmable. Self protecting. Many motor control applications. I used it for single phase slow starting motors.

This vfd worked amazing on my delta 28-640. I need to red7ce the rpms the allow speed to buld up. This unit did the trick would purchase another one if I ever come to that situation again.