2’x8′ brown Ground protection mats 80 T load capacity May 22, 2012 · 2’x8′ green ground protection boards 100 T load capacity 2 #12 in nduit Table 3A, 1/2″ nduit will take up to 4 #12 THW Example: Load: Motor 3 HP, 1 phase, 230V run ground wire with all motors I = 17A NEC []