Consider this scenario… You have a drive with a 240V single phase supply, but an existing or off the shelf pump. You might ask, why use a 240V single phase supply to a drive?
There are 3 reasons:
- You are in a remote location with a single-phase generator supply.
- You have arranged a solar array (in the case of a solar pump drive) to give 240V output for domestic supply reasons, at the correct kW output for the drive.
- You want flexibility in bench testing the drive (if only 240V single-phase is available)
It is important to know that ‘volts in equals volts out’. This means that a single-phase supply at 240V cannot put out 415V (three-phase). In other words, if we have a nominal 240V input, so we can only get three-phase 240V out.
The next step is to inspect the motor terminal connections to make sure they are correct for the voltage.
Looking at our trial motor, we can see that a 240V three-phase supply needs to be connected in Delta, 415V supply needs a Star connection.
What does this mean in practice?
A star connection is accomplished simply by bridging one horizontal row in the connection box.
A Delta connection is easily accomplished by bridging the 3 columns in the connection box vertically.
Out Motor Terminal Box:
So, this motor is correctly wired in Delta configuration, and in this case - is good to go! |