Does the capacity of a transformer has any thing to do with motor stalling ?
Suppose the under capacity transformer is able to start the loaded motor. Would not the motor stall due to excessive voltage drop as a result of under capacity of the transformer ?
Seems like a d?j? vu moment...
If the motor is connected direct on line you have this sort of characteristic:
Clearly, the highest current is at starting. Thus is a double whammy for the supply voltage. Not only is it the highest current but it is at poor power factor which results in greater voltage regulation than the same current at good power factor. Then you're also hit about the lowest torque per amp. If the motor can get past that, things get better all round, so stalling isn't like to be caused by transformer capacity.
This is just confirming what others have already pointed out.
If the motor is fed by a variable frequency drive (not mentioned in your original post) and the supply voltage drops then so will the DC link voltage. Most VFDs default to fixed V/f ratio so there at at least a couple of possible outcomes. Depending on how low the voltage is I can see a couple of possible outcomes. The low DC link might prevent the motor getting maximum frequency thus limiting its speed. And if it's lower than the drive settings the drive will trip. Again, the motor stalling isn't a likely outcome.