Given a 3-phase wye circuit (3 conductors and grounded neutral), with phase currents of L1=58A, L2=74A, L3=64A and N=12A, how does one compute the total current?
Reads like a homework question to me. But anyway - what do you mean by the "total current" in this situation, you have the phase currents, you have the neutral current, what more do you need to know?