I have a question for you regarding multiple motors on a single circuit. At a project, we originally called out for the retractable tables to be connected as 2 tables per 120V, 20A. Each table is less than 1HP and draws less than 6A. As I was reviewing the as-builts I noticed that the contractor connected all 8 tables to 1-20A circuit. Looking at NEC 430.53 we are code compliant with this installation as long as the overload protection for each motor is provided, NEC 430.32. My question is on the motor conductors, NEC 430.24 calls out 125% of the largest motor plus the sum of the additional motors for a total of 41.25A. Are we required to provide #8AWG even though we are protected by a 120V-20A circuit? Seems backwards.
Motor conductors:
NEC 430.24:
125% of the largest motor: 5 * 1.25 = 6.25A
Sum of additional motors: 5A*7 = 35A
Total: 41.25A capacity for the conductors
NEC 310.16 requires that #8AWG conductors be installed to the motor controller in order to withstand the possible load of 41.25A.
Overcurrent protection:
NEC 430.53
Since these motors are not over 1HP and do not draw more than 6A, we comply with this section as long as individual overload protection for each motor is provided per NEC 430.32.
Motor conductors:
NEC 430.24:
125% of the largest motor: 5 * 1.25 = 6.25A
Sum of additional motors: 5A*7 = 35A
Total: 41.25A capacity for the conductors
NEC 310.16 requires that #8AWG conductors be installed to the motor controller in order to withstand the possible load of 41.25A.
Overcurrent protection:
NEC 430.53
Since these motors are not over 1HP and do not draw more than 6A, we comply with this section as long as individual overload protection for each motor is provided per NEC 430.32.