I believe that only having halve of the coil voltage would not produce any where near the magnetism required to pull in a starter. Years ago think it was Cadillac best of the best Allen Bradley had it in their thick product catalogue the minimum required voltage percentage to what they call to seal the starter contacts. Had to be over 85%. Have to be carefull when selecting the minimum size controll transformer when installing several motor starters especially if they are all capable of starting at the same time. Some people only used the sealed current ( maybe 13 to 18 watts for a NEMA size 1 starter ) and not the current it takes to seal contacts. Some Danfoss FC model early drives with the 3 starter bypass function had problems because of slightly undersized control transformer. They placed a 5 to 10 second time on delay timer so only the M1 start contactor that feed the drive would energize then 5 to 10 seconds later the M2 drive output contactor would pull in. Learned so much from drive tech that performed start ups. Would always have a question or two for them and learned more about drives then a few drive classes I attended.
