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How Hard Is the NC SP-PH Exam?
Honest answer: it's very passable — but not because it's easy. It's open book, so the difficulty isn't knowing the answers, it's finding them fast enough. People who treat it like a closed-book test pass; people who plan to "look everything up" run out of time.
The format
| Questions | 40 multiple choice |
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| Time limit | 3 hours (~4.5 minutes per question) |
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| Passing score | 75% — 30 of 40 correct |
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| Format | Open book (2020 NEC + NASCLA guide) |
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| Retakes | Up to 2 per year, with a waiting period based on score |
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Why people fail it
- Page-hunting. With 4.5 minutes per question, you can't afford to read. Untabbed books kill candidates on time.
- Calculations under pressure. Box fill, motor full-load currents, load calcs, and conductor sizing need quick, confident math.
- Wrong-column / wrong-table errors. Reading the 75°C column instead of 60°C, or the single-phase motor table instead of three-phase, is the classic trap.
- The business/law portion. The NASCLA material (contracts, liens, taxes, business structure) is a different book and catches field techs off guard.
What makes it manageable
- It's open book. You don't have to memorize — you have to navigate. That's a learnable skill.
- Generous time if you know your book. 3 hours is plenty when each lookup takes seconds, not minutes.
- Predictable topics. The same nine areas show up every time (grounding, overcurrent, boxes, wiring methods, motors, load calcs, HVAC equipment, general knowledge, law).
How long to study
If you have field experience, plan on roughly 20–40 hours — and spend most of it in your tabbed code book, not reading study notes. The goal is muscle memory: hear a topic, flip to the article in seconds.
The single best prep: drill practice questions with your book open and
find every answer before you commit. Our questions cite the exact NEC article precisely so you can practice that lookup loop. Time yourself in
Exam mode to build the pace.
Make it easier
- Get the right books and tab them using the priority tab list.
- Work the study guide so you know which article each topic lives in.
- Drill the practice exam — use Exam mode with the timer, then re-drill your missed questions.
Related: SP-PH cost breakdown · How to get the SP-PH license · SP-PH vs SP-FALV