Re: OT: phantom 3 phase leakage?


Kevin Oconnor
 

For holiday idle time reading I’ll add to this OT thread too...
There are probability many applications of solid state VFD fixed freq/RPM single to 3P power, these would likely be only for single motor applications. SS VFDs need to be closely matched to the load, so attaching multiple 3P loads to a SS VFD is full of hazards. Static or rotating phase converters are much more practical for 3P load switching. Just size it for the largest combined 3P load expected.
For variable RPM control of 3P motors there are many SS VFDs both US and Chinese that easily interface to 1P, 2P & 3P mains. I have been very happy with controllers from Automaton Direct for converting fixed RPM belt driven speed changing machines to 3P motors with electronic speed control. With these, you must convert drum switches from power switching to logic control, as interrupting the 3P motor under power will fault a VFD. Sometimes chokes are appropriate on one or more input (not output) phases to improve noise conditions.

Kjo

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