Motors Room
Motor questions punish one mistake: mixing FLC with FLA. FLC comes from the tables in Article 430 and sizes the branch-circuit conductors at 125 percent. FLA comes off the nameplate and sizes the overload. Two numbers, two jobs. Learn which table feeds which rule and motor problems stop surprising you.
Last reviewed June 2026 · Staff Answer
A single continuous-duty motor has a table full-load current of 28 amps.
What minimum branch-circuit conductor ampacity does it need?
Pick an answer to see the work and why each wrong choice traps people.
What this room is for
- Separating FLC from FLA and what each one sizes
- Reading the motor FLC tables without second-guessing
- Working conductor, overload, and protection in the right order
What not to post
- Asking for pasted NEC tables. Cite the article and table number.
- Posting real exam questions. Build an original scenario.
- Sharing identifying details.
Answered questions in this room
What is the clean way to practice motor FLC table lookups?
Always start from full-load current in the Article 430 tables, never the nameplate. FLC sizes the branch-circuit conductors and the protection. Nameplate FLA sizes only the overload. Practice by reading the table value first, then applying the rule, so you never plug the wrong current into the wrong calculation.
What is the difference between FLA and FLC for a motor?
FLC is full-load current from the NEC tables in Article 430, and it sizes the branch-circuit conductors and the protection. FLA is full-load amps off the motor nameplate, and it sizes only the overload. They are close but not equal, and the exam writes problems to punish anyone who swaps them. Table for the wire, nameplate for the overload.
Room FAQ
What is the Motors Room?
Motor questions punish one mistake: mixing FLC with FLA. FLC comes from the tables in Article 430 and sizes the branch-circuit conductors at 125 percent. FLA comes off the nameplate and sizes the overload. Two numbers, two jobs. Learn which table feeds which rule and motor problems stop surprising you.
What should I do first in this room?
Start with the daily drill. Pick an answer before reading the explanation, then read why the wrong choices trap candidates.
When should I take the full diagnostic?
Take the full diagnostic when you are not sure which NEC area is costing you points, or when the same miss shows up more than once.
Discussions
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Quick back-and-forth with others studying this room. You post under a pseudonym. Be straight, cite article numbers, never copied code.
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