I've bought a second hand bore pump. A thing of beauty - a 1.5kw single phase mono pump, with external start capacitor setup.

Well, it was cheap, and the start box was missing, and it appears the main shaft to the mono pump is unscrewed.

It is also over kill for our small well.

But as an embedded software guy with a passion for farm hacks, I couldn't resist.

Today I got under the covers of my Chinese 2.2kw single phase VFD. With some assistance from the vendor, was able to connect the run coil and live to "V" and "W" respectively. And after giving it a flick, the motor was away.

However, this still leaves me no start capability, and much mixed information. i.e. "remove the capacitor if you're using a VFD as you WON'T need one". (Apparently I do?).

Then there is the spare "U" phase? Can I configure this as a separate Neutral with an offset phase for the aux. winding? Or connect the two neutrals without a Cap?

Any other magic?

Very keen to master these devices.

Thanks in advance.

 

Ok, I can give an update on this. The wiring is Neutral (Start) Neutral (Run) -> UV (or VU depending on rotation required), and Line to W.

Works a treat. Cheap Chinese unit cost me little more than replacing the start capacitor, with a lot more scope for controlling start and run/speed parameters and interface for an external POT.

Failed to get the Modbus talking, but otherwise, very happy. It was a case where I asked the vendor for a working config, but they just kept randomly pointing at things that may work (but never did).