Can a smaller capacitor do it?

[walker1]

Due to some error, we have been shipped a 3-phase 380V, 350W fan. We, hopfully, ordered a 230V single phase version, but do not have time for a replacement.

I know we can create a semi-phase by using a capacitor. The datasheet covering all the "250" different versions (incl. 48V DC) mentiones 6uF, but it is unclear if it is for one of the other motors!
I have seen 'a rule of thumb' saying 5-10 uF pr. 100W, so 6 seems a bit low.

As the motor is 350W (½ HP or so) I would have expected something like 20uF.

We have a 2uF at hand, but will the fan start with that? The load is of course very low to begin with, but ... ?

All 6 connections to the three windings are available, so I suspect a Delta circuit will give us the best power when running, but starting ... ?

 

[waross]

It will start OK but will probably burn out soon. You may try measuring the current on the three motor leads (just the motor current, not the combined motor and capacitor current) and changing capacitor values until the currents are balanced.
Why bother. Small VFDs are cheap and plentiful. They will accept single phase and output three phase. Your motor will run well with the added feature of speed control.
FORGET the capacitors.

Bill
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"Why not the best?"
Jimmy Carter