Idaho Limited Electrical Refrigeration, Heating & Air Conditioning Installer

Idaho Limited Electrical Refrigeration, Heating & Air Conditioning Installer Exam Prep Checklist

Everything for the Idaho Limited Electrical Refrigeration, Heating & Air Conditioning Installer exam in one place: the bulletin's key facts, the topics and how many questions each carries, the reference books, sample questions with answers, and a prep checklist. PSI gives the exam.

Idaho Limited Electrical Refrigeration, Heating & Air Conditioning Installer Exam Facts

From the official bulletin:

On exam day

• You must present one current, government-issued photo and signature ID (such as a driver's license, state ID card, passport, military ID, or alien registration card) to be admitted.
• Arrive 15 minutes before your appointment time.
• Candidates must bring their own reference materials, and anyone caught writing in references or holding unauthorized materials has the binder seized and is reported to the Division.
• Highlighting, underlining and permanent indexing done before the exam are permitted, while writing during the session and temporary markers such as Post-its are prohibited.
• Only approved items may be brought into the exam room; all other personal belongings, including electronics, writing devices, bags, food and drinks, must be placed in secure storage.

References you may bring

• NFPA 70 – National Electrical Code (2017)
• Ferm's Fast Finder Index (2017)
• Key Word Index by Tom Henry (2017)
• Ugly's Electrical References

Scheduling, changes and retakes

• You may schedule online through PSI's registration website or by calling PSI at 855-340-3713.
• You may cancel and reschedule without forfeiting your fee if PSI receives your cancellation notice 2 days before the scheduled examination date, done by website or by phone (not voicemail or email).
• If you miss your appointment, arrive after the examination start time, cancel late, or lack proper ID, your registration is invalid and you forfeit your examination fee.
• Your score is shown on screen at the end of the exam and a score report is provided, with a diagnostic report of strengths and weaknesses if you fail.
• If you do not pass, you may retake the exam as many times as needed, paying an examination fee for each attempt.

Source: Examination Scheduling Procedures / Examination Guide (Idaho PSI Candidate Bulletin), Effective 7/9/2026. Check the bulletin before test day: fees and rules can change.

Idaho Limited Electrical Refrigeration, Heating & Air Conditioning Installer Exam Topics

The official content outline has 7 topics:

Idaho Limited Electrical Refrigeration, Heating & Air Conditioning Installer Exam Prep Checklist

• Get the reference books the bulletin lists, in the editions it names.
• Learn each book's table of contents and index first.
• Highlight the sections you use most. The exam facts above list the bulletin's rules on tabs and markings, so follow them exactly.
• Start with the biggest topics: 2017 National Electrical Code, NFPA – Chapter 4 and 2017 National Electrical Code, NFPA – Chapter 2 (58% of the exam).
• Take our timed practice exams until you pass several in a row.
• After each attempt, look up every question you missed in your book.
• Practice at the real exam's pace: about 2 minutes 40 seconds per question.

Idaho Limited Electrical Refrigeration, Heating & Air Conditioning Installer Exam Reference Books

The 2017 NFPA 70 National Electrical Code is the allowed reference, and the 2017 Ferm's Fast Finder Index, 2017 Key Word Index by Tom Henry and Ugly's Electrical References may also be used as optional references not used to develop the exam.

Where to get them:

• NEC 2017

Test Day Checklist

• First pass: answer every question you know. Bookmark the rest. Every exam lets you return to bookmarked questions.
• Second pass: work through your bookmarks.
• Pace: 2 hours for 45 questions, which is about 2 minutes 40 seconds per question.
• Last step: answer anything still blank. A blank can't earn a point.

Study Tips

Your license won't show your exam score. Whether you ace it or squeak by, you walk out licensed either way — as we like to say, C's get licenses. Aim to pass, not to be perfect, and don't tally your score as you go; that pressure only drags your performance down.

Reading the material cover to cover usually isn't enough to pass. This is a multiple-choice exam, and multiple choice rewards practice — the more questions you work through under real conditions, the more the terminology and question style become second nature.

On technical questions, don't get bogged down in unfamiliar terminology. If you don't recognize a term, you're unlikely to figure it out on the spot—acknowledge it quickly and move on. Use the surrounding context, answer choices, and familiar terms to guide your reasoning, but don't linger on any single difficult question.

You're given plenty of time, so use as much of it as you need. Don't get rattled when other people finish early — finishing first isn't a prize. Work at your own steady pace and review your answers before you submit.

Idaho Limited Electrical Refrigeration, Heating & Air Conditioning Installer Sample Questions

From our practice question bank, with answers and references:

Sample 1 — 2017 National Electrical Code, NFPA – Chapter 3

Question: Underground conductors entering or leaving an outdoor trench are exempt from ampacity adjustment factors where they have physical protection of rigid metal conduit, IMC, PVC, or RTRC not exceeding 3.05 m (10 ft) in length, provided the number of conductors does not exceed:

• A. 8
• B. 4
• C. 6
• D. 10

Correct Answer: B

NEC 2017, 310.15(B)(3)(a)(3) exempts such underground conductors from adjustment factors only where the protective raceway length does not exceed 10 ft and the number of conductors does not exceed four.

Reference: NEC 2017 Section 310.15(B)(3)(a)

Sample 2 — 2017 National Electrical Code, NFPA – Chapter 1

Question: A personnel door located less than 25 ft from the nearest edge of the working space must open in the direction of egress and be equipped with listed panic hardware where the installed equipment contains overcurrent devices and is rated at least:

• A. 800 A
• B. 600 A
• C. 400 A
• D. 200 A

Correct Answer: A

Per NEC 2017, 110.26(C)(3), where equipment rated 800 A or more containing overcurrent devices, switching devices, or control devices is installed and a personnel door is less than 7.6 m (25 ft) from the nearest edge of the working space, that door must swing in the direction of egress and have listed panic hardware.

Reference: NEC 2017 Section 110.26(C)(3)

Sample 3 — 2017 National Electrical Code, NFPA – Introduction

Question: Per NEC 90.2(A), the Code covers the installation and removal of electrical conductors, equipment, and raceways; signaling and communications conductors, equipment, and raceways; and ______ cables and raceways.

• A. Coaxial
• B. Fiber optic
• C. Optical fiber
• D. Data communication

Correct Answer: C

Per NEC 90.2(A), the Code covers 'the installation and removal of electrical conductors, equipment, and raceways; signaling and communications conductors, equipment, and raceways; and optical fiber cables and raceways.' The specific term used in the Code is 'optical fiber.'

Reference: NEC 2017 Section 90.2(A)

Sample 4 — 2017 National Electrical Code, NFPA Calculations

Question: A single-phase motor is protected by a time-delay (dual-element) fuse, but the fuse sized by the standard percentage table will not carry the motor's starting current. What is the maximum rating to which that time-delay fuse may be increased, expressed as a percent of the motor full-load current?

• A. 150 percent
• B. 175 percent
• C. 225 percent
• D. 200 percent

Correct Answer: C

NEC 2017, 430.52(C)(1) Exception No. 2(b) permits the rating of a time-delay (dual-element) fuse to be increased when the table value will not carry the starting current, but in no case may it exceed 225% of the full-load current. 175% is the standard Table 430.52 value for a single-phase motor, 150% is the table value for wound-rotor and dc motors, and 300% applies to fuses of the 601–6000 ampere classification.

Reference: NEC 2017 Section 430.52(C)(1), Exception No. 2

Online Practice vs. a PDF

• Timed: you practice finding answers under time pressure, not just reading them.
• Bookmarks: flag questions and come back, the way you will on test day.
• New sets: each attempt draws new questions from our bank.
• Scored by topic: your results show which outline topics need more study.

Next Step

• Take the free Idaho Limited Electrical Refrigeration, Heating & Air Conditioning Installer practice exam.
• Study the topics where you scored lowest.
• Read the exam bulletin for the official rules, and see the licensing board's website.