Missouri NASCLA Master Unlimited Electrical Contractor Exam Book Package

Missouri NASCLA Master Unlimited Electrical Contractor Exam Book Package

Get the approved open-book reference set used for the NASCLA-Accredited Trade Examination for Electrical Contractor (Master Electrician/Unlimited Electrician) administered for Missouri through PSI on behalf of the Missouri Office of Statewide Electrical Contractors (OSEC). This book package is built for one purpose: helping you prepare the way the exam is actually taken—by practicing fast lookups, code navigation, and accurate verification inside the same references allowed in the testing center.

On a timed, open-book electrical contractor exam, many candidates already understand the trade but lose points because they can’t find the exact section quickly, miss an exception, or overlook a table note that changes the requirement. This package supports the exam skill that matters most: efficient reference navigation—especially in the NEC—so you can answer confidently and keep a steady pace.

Book-only package: This product is just the books listed below (no course access and no add-on services unless stated elsewhere). It’s ideal for candidates who already have a study plan and want the correct, exam-approved references in hand.

Exam Details

• State program: Missouri Division of Professional Registration – Office of Statewide Electrical Contractors (OSEC)
• Exam administrator: PSI Services LLC
• Exam: NASCLA-Accredited Trade Examination for Electrical Contractor (Master/Unlimited)
• Exam fee (paid to PSI): $125
• Number of questions: 100
• Time limit: 270 minutes
• Passing requirement: 75 correct answers
• Calculator: Silent, nonprinting, non-programmable calculator permitted
• Testing center materials: A physical diagram/blueprint packet is handed out onsite at the testing center

These details are published in PSI’s Missouri OSEC Candidate Information Bulletin for the NASCLA examination program. 

Open Book Test

This examination is verified as an OPEN BOOK test. PSI states that the reference materials listed for this exam are allowed in the examination center, and that code questions are based only on the listed code-book editions. 

Open-book exams reward candidates who can do three things consistently:

• Recognize the topic quickly (what reference controls the question).
• Navigate efficiently (index/table of contents → section → exception/table/note).
• Verify details (exceptions, table notes, conditions, and definitions before committing to an answer).

Licensing Steps

1. Request an application: Request an application and instructions from the Missouri Office of Statewide Electrical Contractors (OSEC).
2. Submit your application to OSEC: Complete the application and return it to OSEC. Missouri determines your eligibility for a license.
3. Receive approval to test: Once approved, you will receive a notification with instructions on how to pay and schedule the examination. PSI is also notified of your approval.
4. Pay and schedule with PSI: After approval, pay the PSI exam fee and schedule your computer-based exam appointment.
5. Take the exam: Sit for the NASCLA Electrical Contractor (Master/Unlimited) examination at a PSI testing center using the approved open-book references.

These steps and the two-year eligibility window after approval are outlined in PSI’s Missouri OSEC bulletin. 

State Requirements

• Licensing authority: Missouri Division of Professional Registration – Office of Statewide Electrical Contractors (OSEC)
• Mailing address: 3605 Missouri Boulevard, P.O. Box 1335, Jefferson City, MO 65102-1335
• Phone: 573-522-3280
• Fax: 573-751-6301
• Email: OSEC@pr.mo.gov
• Testing eligibility window: After OSEC approval, eligibility is valid for 2 years, and candidates may test unlimited times during that period if needed.

OSEC contact information and the eligibility window are listed in PSI’s Missouri bulletin. 

Reference Books

The following references are included in this Missouri NASCLA Master/Unlimited Electrical Contractor Exam Book Package. PSI identifies these references as allowed in the examination center for the NASCLA Electrical Contractor (Master/Unlimited) exam program in Missouri. 

• National Electrical Code (NEC), 2023
  The primary code reference used for code-based questions on the exam. PSI lists the NEC (or NEC Handbook) as an approved codebook edition for this program (2020 or 2023), and this package is aligned to the 2023 NEC you provided.
• Code of Federal Regulations – 29 CFR Part 1926 (OSHA)
  Construction safety standards commonly used for jobsite compliance, hazard controls, and employer responsibilities. PSI’s bulletin lists the 2024 edition in the approved reference set.
• Code of Federal Regulations – 29 CFR 1910 (OSHA)
  General industry OSHA standards supporting broader workplace safety requirements and compliance scenarios. PSI’s bulletin lists the 2024 edition in the approved reference set.
• A Guide to the Project Management Body of Knowledge (PMBOK® Guide), 7th Edition
  Project management fundamentals supporting planning, execution, and professional project controls. PSI lists the 2021, 7th edition in the approved reference set.
• ANSI/ASHRAE/IES 90.1-2022, Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings (I-P edition)
  Energy-efficiency standard referenced for commercial building compliance concepts. PSI lists the 90.1-2022 standard in the approved reference set.
• NASCLA Contractors Guide to Business, Law and Project Management (Basic), 14th Edition
  Business, law, and project administration reference aligned to contractor responsibilities and management concepts. PSI lists the Basic 14th edition in the approved reference set.
• NFPA 70E – Standard for Electrical Safety in the Workplace, 2024
  Electrical safety practices and hazard controls relevant to workplace procedures and scenario-based safety decisions. PSI lists the 2024 edition in the approved reference set.
• Ugly’s Electrical References
  Quick-reference formulas, tables, and calculation support used to verify common electrical math efficiently under timed conditions. PSI lists the 2023 edition in the approved reference set.
• Understanding Electrical Theory for NEC Applications
  Helps connect theory to NEC-style application, supporting calculation questions and code-interpretation reasoning.

All reference titles and listed editions above are drawn from PSI’s Missouri NASCLA bulletin reference list for the Electrical Contractor (Master/Unlimited) exam.

Test Information and Study Materials

PSI’s bulletin includes an exam content outline for the NASCLA Electrical Contractor (Master/Unlimited) examination in Missouri. Major content areas include project design/management, safety, electrical theory and principles, general code requirements, wiring and protection, wiring methods/materials, general equipment use, special occupancies/special equipment/special conditions, and communication systems. 

How to study effectively with a book-only package:

• Practice “topic-first”: Before opening a book, label the topic (NEC requirement, OSHA safety, NFPA 70E safety, project management). This prevents random searching.
• Train NEC navigation daily: Use the index and table of contents to locate the controlling section quickly, then verify exceptions and table notes.
• Use timed mini-sets: Run short timed question blocks to build pace and reduce exam-day stress. Track what slows you down (tables, special conditions, calculations) and drill those areas.
• Verify calculations: Use Ugly’s to confirm common formulas and values, then validate that your answer matches the scenario conditions and NEC requirements.
• Don’t skip safety references: When a question is clearly safety-focused, go directly to OSHA or NFPA 70E instead of trying to force everything into the NEC.

How 1 Exam Prep Helps You Reach Your Goal

1 Exam Prep supports your goal with a trade-focused approach that emphasizes the skills open-book licensing exams reward most: organized study guidance, practical review, practice-oriented preparation, and confidence-building structure. Even with a book-only package, the right study plan helps you turn references into a system—so you can locate answers efficiently, verify details accurately, and maintain better pacing under a real exam time limit.

Our approach is designed to help you build a repeatable method: identify the topic quickly, choose the correct reference, locate the governing rule, confirm exceptions and details, and move forward with confidence—without guaranteeing outcomes or promising results.

FAQ

Is the Missouri NASCLA Master/Unlimited Electrical Contractor exam open book?

Yes. PSI’s Missouri OSEC Candidate Information Bulletin states this examination is OPEN BOOK and lists the references allowed in the examination center. 

How many questions are on the exam and how much time do I get?

PSI lists 100 questions with 270 minutes allowed, and you must answer 75 correctly to pass. 

Who do I apply with first—Missouri OSEC or PSI?

You apply with Missouri OSEC first. After OSEC approval, you pay and schedule the exam with PSI. 

Does this product include a course?

No. This is a book-only package that provides the exam reference books listed on this page.

Which NEC editions are approved for this exam?

PSI’s Missouri bulletin lists the NEC (or NEC Handbook) as approved in 2020 or 2023 editions. This package is aligned to the NEC 2023 you provided. 

Are diagrams or plans provided at the testing center?

Yes. PSI notes a physical diagram/blueprint packet is handed out onsite at the testing center. 

What’s the best way to use these books to prepare?

Focus on navigation and verification: identify the topic, go to the correct reference, locate the governing section quickly, confirm exceptions/table notes, and practice timed sets to build pacing.