hector_hto1959 , friend, if you want to use, 2 separate supplies, 110v. (120v), and 3 current wires arrive at your connection, you have no problem using the neutral cable, in the 2 circuits of 110v (120v).
In other words, if your electrical system is 220v. in 2 phases and 1 neutral, it means that the neutral is common to the 2 phases, and is used to make 110v circuits. (120v.) To power all 110v equipment. (120v.), Regards.
alualo.