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NEC CODE NEC 2023

Motor Circuit Calculations -3 (NEC Code Questions)

Online Practice Test on Motor Circuit Calculations

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Frequently Asked Questions

Yes — free, no signup required. Each question links to the relevant NEC article so you can study the code directly.

The National Electrical Code (NFPA 70) is the benchmark standard for safe electrical installation in the US. It is updated every 3 years by the NFPA.

Study the edition adopted by your state. As of 2025, most states use the 2020 or 2023 NEC. These tests are written to the 2023 edition.

The most tested articles are 100 (Definitions), 200–250 (Wiring & Grounding), 300–314 (Wiring Methods), 400–411 (Conductors), 430 (Motors), and 700–701 (Emergency Systems).

How to Use This Practice Test

This Motor Circuit Calculations -3 (NEC Code Questions) has 10 questions with detailed answers and NEC references. Take the full test, review every wrong answer, and look up the NEC article it references before moving on.

Tip: Use the NEC index (back of the book) — find answers by keyword, not by article number.

Topics covered: NEC articles 100, 210, 220, 240, 250, 300, 310, 430, and special occupancies.
Passing score: Aim for 80%+ on NEC code tests before exam day.
Questions: 10 multiple-choice, one correct answer each

10

Questions

15 min

Time

70%

Pass

Timer starts immediately. Progress is auto-saved.

Motor Circuit Calculations -3 (NEC Code Questions) — Question List

Question 1: In no-case the rating of a shot circuit ground fault protective device for single motor compressor should not exceed ................ percent of the motor compressor rating?

175
225
200
150

NEC Reference: NEC 440.22(A)

Question 2: What is the minimum ampere rating of short circuit ground fault protective device that can be used for industrial motor compressor?

10 A
15 A
20 A
25 A

NEC Reference: NEC 440.22(A)

Question 3: Which of the following size conductor is required for a 18 A motor compressor connected to 240 V circuit at 75 <sup>0</sup>C?

12 AWG
10 AWG
14 AWG
8 AWG

NEC Reference: NEC 22.5

Question 4: Which size branch circuit protection is required for 20A motor compressor connected to 240 Volts circuit?

40 A
35 A
45 A
50 A

NEC Reference: NEC 440.22(A)

Question 5: What size branch conductor is suitable for 5 HP, 208 V three phase motor?

12 AWG
10 AWG
8 AWG
14 AWG

NEC Reference: NEC 16.7

Question 6: The single pole switches can be used to control the motors when those are rated at ................... hp or less.

1/2
1/4
3/4
1

Question 7: The branch circuit over current device of the stationary motor which are rated less than ........... may serve as the controller of motor.

5 hp
3 hp
1 hp
1/8 hp

NEC Reference: NEC 430.81(A)

Question 8: A 2400 volts motor disconnecting means must be capable of being of being locked in the ......................

closed position
open position
on position
both open and close position

Question 9: The overload protection must be provided for the motor if it is rated more than ......... hp

1/8
1/4
1/2
1

NEC Reference: NEC 430.32(A)

Question 10: A disconnecting means should be located in sight from a motor not more than ............... distance.

25 feet
50 feet
70 feet
90 feet

Key NEC References for This Test

Article	What It Covers
Ch. 1–4	General rules — apply to all installations
Ch. 5–7	Special rules — override Ch. 1–4 where they conflict
Ch. 8	Communications — completely independent of Ch. 1–7
Ch. 9	Tables — referenced by articles, not standalone enforceable rules
Art. 210.12	AFCI — major expansion in NEC 2026
Art. 230.67	Surge protection at service equipment — new NEC 2026

Study Tip: Learn the NEC index — use keywords, not article numbers. Practice finding 5 different topics in under 2 minutes each.

EXAM CARD NEC CODE

Questions10

Time limit15 min

Pass score70%

Code editionNEC 2023

DifficultyIntermediate

Last reviewedJun 2026

Timer starts immediately. Progress is auto-saved.

Source: NEC 2026 (NFPA 70)