I'd spec #14 off hand.
Is the 208VAC in any way linked to the load?
It had better be isolated from back EMF.
You may need parallel runs depending on the coil. Super long runs bring with themselves impedances that may surprise you. At 208VAC your run must go up and back 4,200 feet. That's 1,400 yards! Further, can I assume that the control circuit must hold firmly?
You may benefit by using a PLC/ compounded relay at the motor to reduce the control current. The master relay could be DC which makes for crisp logical states.
