VFD with a difference

[Fazerruss]

Does anyone have any useful links on converting a static phase converter to a rotary phase converter

How would you size the dummy motor ???

Its really easy. All you do is connect a motor to the same output as used for the machine you are running. I went a step further and fitted the VA meters so I can see the voltage and current draw for each leg. This allows me to fine tune the output with the "hp switch" to get the motor to run smooth. The smoother and quieter means its input voltage is correct ballanced. ( all the hp switch does is connect extract capacitors to boost the voltage on the missing leg)

Pony Motor size isn't crucial. Something around half the hp of the lathe motor. This is mine.




I read a good book on motors before doing all this ( can't remember the name of it) and one interesting phenomenon is the more motors you have running helps smooth out the voltage. Every spinning motor acts as a flywheel and the inertia of the spinning pony motor helps with surge in demand from the machine motor. (The pony motor is acting as a generator for the 3rd missing leg)

 

[Memmeddu]

Just fit a pony motor to your static then you will have a true rotary phase converter.

I have the same lathe and motor. It works perfectly View attachment 522849View attachment 522850

My lathe is slightly bigger than yours, but it has not a Norton box or feed bar

 

[Piero]

I am quite liking the idea of a 230v input 380v 3 phase output VFD. as mentioned further up in this post.

I was unaware they did such things

I am currently trying to find a quality manufactured one as all of my VFds are Invertex at the moment, Shneider or Mitsubishi would be good options ( I don't know if they do them) as I don't care much for cheap VFds

 

[Wedg1e]

Your idea involves buying a 415v in 415v out VFD.

It is possible to buy 230v in 415v out VFDs. In the UK, Drives Direct or JFK Electrical.

Yep, I've used a TECO 240 1ph-415V VFD (2HP I think) for several years on my Boxford VSL with no issues.