Idaho Limited Electrical Manufacturing Equipment Installer Exam: A Practical Study Guide
The Idaho Limited Electrical Manufacturing Equipment Installer exam tests the rules and the reference books behind the work. This guide lays out the job: the key facts from the official bulletin, what the exam covers, the books you need, sample questions with answers, and how to get ready. PSI gives the exam.
The Idaho Limited Electrical Manufacturing Equipment Installer Exam at a Glance
Here's the rundown from the official bulletin:
| Questions | 40 questions |
| Time limit | 2 hours |
| Passing score | a minimum score of 70 |
| Books in the exam room | Open book |
| Exam fee | $75 |
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 are responsible for bringing their own reference materials, no writing is allowed in them during the examination session, and anyone caught writing in references or possessing unauthorized materials will have their binder seized and be reported to the Division.
- Pre-exam highlighting, underlining and permanent indexing are permitted, while writing during the exam 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
- 2017 NFPA 70 – National Electrical Code (ISBN-13: 9781455912773)
- 2017 Ferm's Fast Finder Index (ISBN-13: 9781890659790)
- 2017 Key Word Index by Tom Henry (ISBN-13: 978099788574)
- Ugly's Electrical References (ISBN-13: 9781284275919)
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.
What the Idaho Limited Electrical Manufacturing Equipment Installer Exam Covers
The official content outline breaks the exam into 6 topics:
| Topic | Questions | Share of the exam |
|---|---|---|
| 2017 National Electrical Code, NFPA – Introduction | 6 | 15% |
| 2017 National Electrical Code, NFPA – Chapter 1 | 6 | 15% |
| 2017 National Electrical Code, NFPA – Chapter 2 | 9 | 22% |
| 2017 National Electrical Code, NFPA – Chapter 3 | 10 | 25% |
| 2017 National Electrical Code, NFPA – Chapter 4 | 6 | 15% |
| 2017 National Electrical Code, NFPA – Chapter 7 | 3 | 8% |
How to Get Ready for the Idaho Limited Electrical Manufacturing Equipment Installer Exam
Treat your reference books like your tools. On an open-book exam you don't need every rule memorized. You need to know which book holds it and where to find it.
Buy the books the bulletin lists, in the editions it names. An older or newer edition can put the answer on a different page, or change it.
Learn your way around each book before you study anything else. The table of contents and the index are your layout.
Highlight what you look up most. The exam facts above list the bulletin's rules on tabs and markings, so follow them exactly.
Do the big jobs first. 2017 National Electrical Code, NFPA – Chapter 3 and 2017 National Electrical Code, NFPA – Chapter 2 make up 48% of the exam.
Put in the reps with timed practice exams. The clock trains you to find answers at the pace the real exam needs: about 3 minutes per question.
Measure twice. When you miss a practice question, find the section in your book, read it and mark it. Keep at it until you pass practice exams consistently.
The Books for the Idaho Limited Electrical Manufacturing Equipment Installer Exam
The allowed reference is the 2017 NFPA 70 – National Electrical Code, 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.
Where to get them:
Working the Exam on Test Day
Work the exam in two passes. On the first pass, answer everything you know and bookmark the rest. Every exam lets you come back to bookmarked questions. On the second pass, go back to your bookmarks and take them one at a time.
Don't get hung up on one question. You have 2 hours for 40 questions, which is about 3 minutes per question. Before you finish, make sure nothing is left blank.
Study Tips
Our practice exam is specifically designed to mimic the testing conditions at all exam centers. While untimed PDF study guides might help with studying, they don’t prepare you for the challenge of managing your time during an actual test.
Know your way around each book's index and table of contents. Open-book exams reward speed: you need to find specific items quickly.
This practice exam mirrors the real PSI exam — the same number of questions, drawn from the same topics. Practicing in that format now means no surprises when you sit for the real thing.
If you're stuck on a problem, don't waste time—move on. Before you do, however, quickly eliminate any obviously wrong answer choices. Even ruling out one or two options significantly improves your odds of guessing correctly. Eliminate what you can, make your best guess, then move on.
Sample Idaho Limited Electrical Manufacturing Equipment Installer Questions
These come from our practice question bank, each with its answer and the reference behind it.
Sample 1 — 2017 National Electrical Code, NFPA – Chapter 1
Question: Where metallic plugs or plates are used to close unused openings in a nonmetallic enclosure, they shall be recessed at least ______ from the outer surface of the enclosure.
- A. 1/2 in.
- B. 1/4 in.
- C. 3/8 in.
- D. 1/8 in.
Correct Answer: B
NEC 2017, 110.12(A) requires unused openings to be closed to afford protection substantially equivalent to the wall of the equipment, and where metallic plugs or plates are used with nonmetallic enclosures they must be recessed at least 6 mm (1/4 in.) from the outer surface.
Reference: NEC 2017 Section 110.12(A)
Sample 2 — 2017 National Electrical Code, NFPA – Chapter 4
Question: You are an electrical contractor sizing conductors for a wye-start, delta-run motor installation. The motor is rated at 100 HP, 460V, 3-phase. According to the NEC, what is the minimum ampacity required for the branch-circuit conductors between the controller and the motor?
- A. 125 percent of the motor full-load current
- B. 62.5 percent of the motor full-load current
- C. 72 percent of the motor full-load current
- D. 100 percent of the motor full-load current
Correct Answer: C
According to the National Electrical Code (Page 502, Section 430.22(C)), for a wye-start, delta-run connected motor, the ampacity of the conductors between the controller and the motor shall not be less than 72 percent of the motor full-load current rating. This is because the individual motor circuit conductors carry 58 percent of the rated load current, and 58% × 1.25 = 72%.
Reference: NEC 2017 Section 430.22(C)
Sample 3 — 2017 National Electrical Code, NFPA – Chapter 7
Question: A Class 1 power-limited circuit must be supplied from a source having a rated output of not more than which values?
- A. 60 volts and 1000 volt-amperes
- B. 24 volts and 750 volt-amperes
- C. 30 volts and 1000 volt-amperes
- D. 30 volts and 500 volt-amperes
Correct Answer: C
Per NEC 2017, Section 725.41(A), Class 1 power-limited circuits shall be supplied from a source that has a rated output of not more than 30 volts and 1000 volt-amperes. Class 1 remote-control and signaling circuits, by contrast, are limited to 600 volts with no power-output limitation.
Reference: NEC 2017 Section 725.41(A)
Sample 4 — 2017 National Electrical Code, NFPA – Chapter 3
Question: Solid aluminum conductors in sizes 8, 10, and 12 AWG are required to be made of which conductor material?
- A. Copper-clad aluminum of equivalent area
- B. AA-8000 series electrical grade aluminum alloy
- C. Aluminum conductor steel-reinforced strand
- D. AA-1350 series electrical grade aluminum
Correct Answer: B
NEC 2017, 310.106(B) requires solid aluminum conductors 8, 10, and 12 AWG to be made of an AA-8000 series electrical grade aluminum alloy conductor material; the same requirement applies to stranded aluminum 8 AWG through 1000 kcmil marked RHH, RHW, XHHW, THW, THHW, THWN, THHN, SE Style U, and SE Style R.
Reference: NEC 2017 Section 310.106(B)
Why Practice Online Instead of With a PDF
A PDF is like reading about a job instead of doing it. Our practice exams are timed and on a screen, so you practice finding answers with the clock running. Each attempt draws a new set of questions from our bank, and your results break your score down by topic so you know where to put in more work.
Get Started
Take the free Idaho Limited Electrical Manufacturing Equipment Installer practice exam to see where you stand, then put your time into the topics that need it. For the official rules, read the exam bulletin, and see the licensing board's website.