since you indicate that its a single-speed, dual voltage motor, it probably has 9 leads coming out of it, although, it could possibly have as few as 6, or as many as 12. please let me know how many leads it has coming out, and any designation markings on each lead. is it an IEC motor, or a NEMA motor? it should say, one or the other on the nameplate.

if its a 6 lead NEMA motor, it can be WYE connected for high voltage,(480), or DELTA connected for low voltage (240). the connections for this type of motor are as follows:
high---L1/1, L2/2, L3/3----and 4,5,6 tied together.
low---L1/1,6--L2/2,4--L3/3,5

if its a 9 lead NEMA motor, it can be connected as follows:
wye-connected high---L1/1, L2/2, L3/3----4&7 joined--5&8 joined--6&9 joined
wye-connected low---L1/1&7, L2/2&8, L3/3&9----4,5,6 tied together
delta-connected high---same as wye-connected high
delta-connected low---L1/1,6,7--L2/2,4,8--L3/3,5,9

it is probably one of these configurations. if it is in fact, a 12 lead motor, please let me know and i'll post the wiring configurations for it separately, as the 12 lead config. is a little more involved, and theres not much sense in taking up space here posting it, if you dont need it. [Linked Image]

also, let me know if its an IEC motor, and not NEMA, although i think, from your information, its probably NEMA.

hope this helps.

gramps [Linked Image]