Motor + Grounding + Calculation Bootcamp

The three areas that decide most exams.

Motor sizing, grounding electrode rules, and calculation traps cause more failures than any other topics. This is the bootcamp.

Motor, Grounding, and Calculation Bootcamp

These are the areas most likely to create false confidence. Students think they know the trade, then the exam asks a rule-context question.

Motor Split

Before solving a motor question, ask what is being sized:

  • Branch-circuit conductors: usually Article 430.22 pattern
  • Overload protection: Article 430.32 pattern, where 115%/125% confusion appears
  • Branch short-circuit and ground-fault protection: Article 430.52
  • Feeder with multiple motors: Article 430.24
  • Disconnect: Article 430.102 and related rules

Memory hook: motor questions are five different questions wearing the same hard hat.

Grounding Split

Before choosing a table, ask what conductor you are sizing:

  • GEC: grounding electrode conductor, usually 250.66
  • EGC: equipment grounding conductor, usually 250.122
  • Grounded conductor: neutral, not an equipment ground
  • Bonding jumper: connects metal parts for continuity

Memory hook: GEC goes to the dirt; EGC goes with the circuit.

Calculation Reps

Daily reps should include:

  • Ohm law
  • Single-phase VA
  • Three-phase current
  • Voltage drop
  • Continuous load 125%
  • Motor conductor 125%
  • Motor overload percentage condition
  • Box fill count
  • Conduit fill table path

The app should score setup separately from arithmetic. Many students can multiply; they just multiply the wrong thing.