Motor Connection History

[pephil]

When dealing with poly phase AC motor connections we see line designations of T1, T2 and T3. Does anyone know the history as to why the "T" designation is used ??

 

[jbartos]

It may stand for "motor terminal 1, 2, 3," however, there are other designators, for example, L1, L2, L3 that could stand for Line 1, 2, 3. Also, various industry standards may have an impact on motor line designation. For example NEMA MG-1 could be checked for T motor terminal designations.