Star/Delta Convertor for 220V/380V Three-Phase Motor

you should declare this specification before order, I know our chinese factories can winding according to your voltage value.

When it is above 7.5 HP we need to use star/delta convertor but it was impossible for us so we have to supply direct on line

What is it meaning? its vague and odd.

230V/400V should work fine with 220V/380V motors, which is within 5%.

Dear Sagara,

your question are not complete, how many terminals or wires you see on the motor, if there are 6, it should be normal, just connect the U,V,W,V1,W1,U1 accordingly,if there are only 3, then you have to use DOL starter or you may also use a soft starter, to me 7.5 hp is still ok for DOL starter as long as the incoming breaker could take the starting current.

pls be more specific if this does not answer your question.

regards

William Tan

As Bill mentions the voltage should be fine, and as you haven't mentioned the motor frequency is different then there is no real issue.

With the Star/Delta "convertor" what is the issue? The motor voltage you state is 220/380 so the assumption is the necessary motor terminals are available. If you dont need to use a reduced voltage start for supply or load reasons then DOL starting is fine. But if you do then look at using a simple soft starter, the pricing for the simple models make it more appealing than Star/Delta and you will only need a single 3core +Earth motor cable.

The voltage difference is not an issue. You have written your motor is a 220/380 V one. If that means that all 6 of the coil end are available you can use a standard start/delta starter.

You can use either motor on either supply they will run fine the voltage variation doe not effect the motor at all. In fact motor manufacturers only change the name plates dependant on the country they are exporting to the winding stays the same. I do not understand the problem it is standard procedure on electric motors to bring the six leads to the terminal box and bridge them there. If they have been wound with the star point buried or as 400v star then they should be labeled accordingly. if they are labeled as you say then they will have a six terminal connection block and star delta connection should be simple.

The ability of the motor to start <...direct on line...> is entirely a function of the resilience of the motor supply to take the starting current, which is around 5 times the full load current for as long as it takes the motor to "get away". Checking the supply, testing, calculating and certifying as safe is entirely within the domain of a qualified local Electrician. Were the installation in the UK, then British Standard 7671 would apply; protocols for cable calculations and and power supply capabilities in relation to motor starting are contained therein.

Make some phone calls.