220V Single-Phase Motor Soft Starter Module controller2KW4KW6KW8KW Motor Online Soft Starting Fan Pump Pressure Reducer Conveyor (Color : SSR 100WA R1(4KW))

I installed this on my water well and now it can start when running on solar battery backup. Inrush amps went from about 70 to 30. I could have adjusted it lower, but have read that water well pumps can fail prematurely if they don't come up to speed quickly. I get pressure in about a second. For longevity concerns, I only plan on using this during power outages so I will install a bypass switch. The seller says I can use jumpers across the input and output terminals and it won't harm the device. That's much simpler than using a 4 pole switch to isolate it.I bought the 4Kw version. My well draws 12 amps steady state and the soft start gets warm so I will add a heat sink. That's where my first quibble comes in. It will be difficult to mount this inside an enclosure and also have a heat sink because of the way the mounting holes are arranged. I may try to find an aluminum enclosure that will provide heat sinking and also make it easy to add a heat sink on the outside.The other quibble is the adjustments. As others have said, there is no manual. I learned that the time adjustment has more effect on the inrush than %. BTW, increasing the time reduces the inrush and surprisingly, increasing the % increases the inrush. I have mine set to 2.5 seconds and 50%.Other than that it worked great in initial testing. Time will tell how robust it is.