Hopefuldave
Intergalactic pot-mender
- Messages
- 2,543
- Location
- The Shed of Danger, surrey, England
Ok, first of all, are you sure you need 415v? Most European motors below 3 or 4 HP can be wired for 415 or 240v, you may be able to run your machines on 240v - look inside the connection boxes on the motors and if there are 6 wires coming from the windings they are dual-voltage.
If they are, and 3 wires are linked together then the motor is in star connection for the higher voltage (On the motor plate it should say 240/415) and you can move the links to put it in delta for 240v - check this as it will make your life easier!
If you only have 3kw at 240v available it will limit what you can use - is that the rating for the power outlet, or the whole supply? If it's the outlet you could have an electrician install a 32 amp socket from a new type C or D breaker in the supply and that would allow up to about 8 kw (I did).
I didn't record every step in building my converter, there's a lot of experimenting and trial-and-error - every motor and configuration is different
A quick easy rule if you do definitely need 415v is to start from capacitor values for 240v you'll find on Practical Machinist then divide by 3, that takes in the increase in voltage by root3 and the decrease in current by root3, so the capacitor impedance increases by a factor of 3 = reduction in capacitance by factor of 3.
Have fun experimenting!
Dave H. (the other one)
If they are, and 3 wires are linked together then the motor is in star connection for the higher voltage (On the motor plate it should say 240/415) and you can move the links to put it in delta for 240v - check this as it will make your life easier!
If you only have 3kw at 240v available it will limit what you can use - is that the rating for the power outlet, or the whole supply? If it's the outlet you could have an electrician install a 32 amp socket from a new type C or D breaker in the supply and that would allow up to about 8 kw (I did).
I didn't record every step in building my converter, there's a lot of experimenting and trial-and-error - every motor and configuration is different
A quick easy rule if you do definitely need 415v is to start from capacitor values for 240v you'll find on Practical Machinist then divide by 3, that takes in the increase in voltage by root3 and the decrease in current by root3, so the capacitor impedance increases by a factor of 3 = reduction in capacitance by factor of 3.
Have fun experimenting!
Dave H. (the other one)