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Practice question · NEC Table 210.21(B)(2)
What Is the Max Load on a 15-Amp Receptacle Circuit?
The max load on a 15-amp receptacle circuit is not 15 amps. That surprises a lot of apprentices, and the exam counts on it. Receptacles get the 80% rule too, and the table in Article 210 proves it in one row.
Exam-style question (Sparky QOTD)
Per Table 210.21(B)(2), the maximum cord-and-plug-connected load on a 15-amp receptacle circuit is:
A. 15 amps
B. 12 amps
C. 10 amps
D. 20 amps
Answer: B) 12 amps. A 15-amp circuit allows 12 amps maximum receptacle load under Table 210.21(B)(2).
Where to Find It
Open your Code book to Article 210 and find Table 210.21(B)(2). Read the row for a 15-amp circuit. The maximum cord-and-plug-connected load shown for that circuit is 12 amps. You do not need to calculate anything else. The table has already applied the limit for you, so your job is to find the right row and trust the value in it.
Why 12 Amps
The explanation in the bank puts it plainly: Table 210.21(B)(2) gives a 15-amp circuit a 12-amp maximum receptacle load, and that is the 80% rule. Twelve is 80% of fifteen. Once you see that relationship, the row is easy to remember and easy to spot under time pressure.
That is also why option A, 15 amps, is wrong even though it matches the circuit rating. The circuit rating and the maximum cord-and-plug-connected load are not the same number in this table. The question asks for the load, not the circuit size, so you answer with the load value from the table: 12 amps.
Tab Article 210 at Table 210.21(B)(2) and write the bank note next to it: "receptacles get the 80% rule too." That one line is the whole concept, and it will remind you not to answer with the circuit rating.
The Trap
Option A, 15 amps, is the trap for anyone who reads "15-amp circuit" and stops. Option D, 20 amps, is larger than the circuit itself. Option C, 10 amps, is under the table value. The exam is testing whether you separate two ideas that sound alike: the rating of the circuit, and the maximum load the table allows you to plug into it.
Exam Tip
If the stem names Table 210.21(B)(2), go straight to that table. Do not work from memory and do not do extra math. Find the circuit rating in the table, read across to the maximum load, and pick 12 amps for a 15-amp circuit. Table-named questions are free points if you actually open the table.
Keep Drilling
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