I’ve done the cheap Chinese VFDs from eBay, struggled through the Chinglish instructions manuals and still keep forgetting that the default startup frequency is usually something stupid like 20Khz.

The major drawback to using this cookie cutter VFDs is you can rarely utilize the existing drum switch or push buttons on that vintage 3-phase grinder you are trying to get running off single phase. The VFD must be the first device inline from the wall plug with any switches feeding into it the VFD to turn it on or off.

What if you could have a dead simple VFD with no complicated menu/display and just a few settings all set by dip switches? Oh, and you can use your old drum switch or contactor box, just wire the VFD between the plug and the machine and you are set. No overload conditions, it just works!

This is the way I have been wiring my 3-phase equipment for years and it’s proven to be the easier way to run old crusty 3-phase grinders, lathes and other equipment.

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Filed under: VFD Talk - @ February 14, 2025 2:29 pm