Motor Calculations: From FLA to the Licensing Exam

The one topic that shows up on every journeyman and master exam.

Motor problems are the highest-point-value questions on most licensing exams. Nail the FLA → conductor → OCP → disconnect path and you gain 15–20 points.

0% complete · 0/5 lessons · 0/5 quizzes passed

What you'll learn

Module 1
Full-Load Amperes (FLA)
Table 430.247 / 248 / 249 / 250. Never use nameplate for conductor sizing.
1 lessons · 4 questions
Module 2
Branch Circuit Conductors — the 125% Rule
430.22: conductors sized at 125% of table FLA.
1 lessons · 4 questions
Module 3
Motor Overcurrent Protection (OCP)
430.52 and Table 430.52 — inverse-time 250%, dual-element fuse 175%, instantaneous trip 800%.
1 lessons · 4 questions
Module 4
Motor Disconnect and Controller
430.102 disconnect requirements; controller must break locked-rotor current.
1 lessons · 3 questions
Module 5
Full Motor Circuit Calculation — Exam Drill
HP + voltage → FLA → conductor → OCP → disconnect. In 90 seconds.
1 lessons · 4 questions