240v Single Phase VFD (diagram wanted please)

[SvenIronhand]

So I have a problem. I need to build a VFD to run a pool pump motor. It's a 1.1kw/1.5HP motor (single phase). I have lots of all sorts of components at home. Also I'm in South Africa where we have 240v supply.
So the question is does anyone know of a place where I can find a circuit diagram for a DIY 1.5kW/2HP VFD. I've looked but haven't really found anything. I don't have much money so I need a free or very cheap less than AU$15 diagram.

[WattsThat]

It’s a fools errand attempting to DIY speed control a single phase ac induction motor.

You cannot find a schematic because they don’t widely exist. Single phase induction motors don’t lend themselves to being speed controlled since there are usually one or two capacitors involved to create a phase shift required for starting and maintaining rotation along with a centrifugal switch that drops out the start capacitor when the motor reaches a preset speed.

If you cannot afford a proper three phase motor that can be controlled with a commercial single phase input/3 phase output VFD, just leave things as they are since the only thing you’re likely to achieve is a pile of dead parts, a failed motor and a very unusable, dirty pool.

[SeanB]

Easiest thing is to go find a donor 3 phase motor in the same frame size as that probably Speck pump, and do a coil transplant with the existing motor. 1.1kW is a common size, and you will find a WEG or Bonfiglioni motor that size easy enough, and so long as they are the same frame size they should fit into the frankenstein configuration. You cannot easily do a complete motor transplant, as the typical pump uses the shaft as the impellor drive, and there are not many extended shaft motors around, I had to have some small one's rewound because of that.

Then there are plenty of 3 phase drivers around to power it, though you will not really get much of a control range over just bang bang switching the motor, those pumps are pretty not going to be efficient below around 40Hz anyway.

I am going to get around to doing that to my drill press, though I was able to get a near perfect  motor at my local scrap yard, old lift door motor in the right frame size, and with the bonus of also having the right shaft diameter and length, though if it does not fit the pulley I will be transplanting the rotor from the 2 anyway.

[Ground_Loop]

I am going to get around to doing that to my drill press, though I was able to get a near perfect  motor at my local scrap yard, old lift door motor in the right frame size, and with the bonus of also having the right shaft diameter and length, though if it does not fit the pulley I will be transplanting the rotor from the 2 anyway.

I highly recommend VFD for a drill press.  I've had one on mine for years.  Its nice to have ultra low speed (including belt sheeve reduction) and reversing for things like tapping holes.