AC 115/250V 20A CW4L2-20A-S Noise Suppressor Power EMI Filter

What I liked...Very well made, hermetically sealed, feels very solid, good quality hardware, easy to install, very effective at eliminating the EMI/RFI from my Pioneer heat pump.What I didn't like...NOTHING!!This filter works fantastic. Just installed a Pioneer 24K BTU heat pump. The heat pump works very well, but it did produce a fair amount of EMI (electromagnetic interference) in the household wiring, and the wiring between the inside & outside heat pump units. I used a Tri-Field meter to measure for the presence of "Dirty Electricity" on the household electrical mains wiring. There were electrical pulsations from the wiring everywhere, from the electrical panel all the way back to the outside compressor.I simply mounted another electrical cutout box beside the previous outside compressor cutout box, removed the guts, mounted the filter in series with the 240v mains, secured the box cover to prevent curious fingers, and job complete. (I recommend using #12 Romex wiring pigtails with crimp ring terminals on the filter, then just wire nut the unit in series with the AC mains to the unit.)There was no more measurable EMI in the house, either from the AC mains wiring under the floor, or from the inter-connecting cable from the inside unit to the outside unit. There was also no detectable interference to my Amateur Ham radio station either, which has antenna cables only 12 feet away.Dirty electricity is a real thing. I am electrically sensitive, and my wife is electrically hyper sensitive. If you don't know what dirty electricity is, Google it. You may be surprised!!!Most all "Energy Efficient/Energy Saving" electrical equipment pulses the power on & off, creating superimposed pulses on the AC household wiring. To be effective, you must stop these pulses at the source, and this unit does it very well.I also measured the electrical mains from the power company with a "GreenWave" broadband EMI meter before and after heat pump installation. This unit measures the "Dirt" or undesirable pulses on the incoming electrical wiring. One line (L1) was about 103mV, the other (L2) was about 198mV. It is recommended to keep both lines below 100mV (millivolts) for areas of human occupancy. When the heat pump was initially turned on, L1 went to 1400+ mV, and L2 went to 1500+ mV. Not good. After the EMI filter was installed, both lines returned to pre-heat pump installation levels. This says it does it's job. Neither I or my wife are bothered by the heat pump now. Buy one. It works!!

Used this filter for the AC power going into my inverter/VFD powering a 2.2kW spindle for my CNC router @ 220V. Before grabbing this filter, I could barely turn the VFD on without my grbl-based cnc controller going into danger mode and canceling whatever I was doing, even from a meter or two away. The EMI noise from the freakin thing killed a limit switch too! 2 days and -$17 later, and I have a machine I could probably run until the sun burns out. I paired this with some ferrite chokes for good measure, but I can say for sure that this bad boy's doing most of the heavy lifting. If you plan on using it with a VFD, make sure to ground it properly (so not at the VFD's ground, but at a star ground point). YMMV with this thing of course, but it turned my machine from a hunk of scrap to a scrap hunk generator-just like I intended.

I've had a K40 chinese laser for over a year. One of the mant issues I had was the laser hanging, resetting or loosing conection to the computer every now and then, when some other device was turned on or off.After I installed this filter between the mains connector and the power supply, all these problems just went away.

Filter has easy to read and understand markings printed on it and is nicely constructed making it durable enough for real world, out in the field use. I was having an issue with a breaker tripping on a control panel because my panel is too close to a 1000 amp welder. Since installing this filter in my control box I have not had any problems with the breaker tripping.

I installed a Variable Frequecy Drive (VFD) on a milling machine to convert my 220V single phase power to 3 phase. I bought this and some inline ring type filters to cut down on electrical noise so nearby computers and CNC controllers wouldn't be affected.Price was decent, and it seems to be doing it's job.

So far no problems seems to be working the way I expected

Needed a noise filter to eliminate EMI coming from a tread mill to my internet router. It seems to be working.Do NOT turn the nuts on the threaded connectors against the can/chassis. Tighten the two nuts against each other, not againt the can.