EEI CAST Test Study Guide: How to Pass the Utility Aptitude Test
The EEI CAST is the gatekeeping test for lineman, substation, and skilled-trades apprenticeships at electric utilities across the United States. It is not a credential exam — it is a ranking tool. Your score determines where you sit on the hiring list, so preparation is the difference between getting the call and waiting for the next round. This guide covers exactly what is on the test, how it is scored, and the most efficient way to prepare.
Take the free EEI CAST aptitude practice testWhat is the EEI CAST test?
The CAST (Construction and Skilled Trades) is a standardized aptitude battery published by the Edison Electric Institute (EEI), the trade association for investor-owned electric utilities. It is used to screen and rank applicants for construction, lineman, substation technician, cable splicer, and related skilled-trades positions at utility companies. The test measures the cognitive and reasoning skills that predict success in technical utility training programs — not knowledge you are expected to already have, but the ability to learn it.
Which utility companies use the CAST?
The CAST is widely used by investor-owned electric utilities throughout the United States. Utilities that use EEI assessments include ComEd (Illinois), PG&E (California), Con Edison (New York), Duke Energy (Southeast and Midwest), Eversource (New England), Ameren (Missouri and Illinois), Entergy (South), PPL (Pennsylvania), AEP (multi-state), and many others. Each utility administers the test through its own hiring process or a third-party testing vendor — contact the utility's HR department or check its careers page to confirm which assessment you will take.
What sections are on the CAST?
The CAST has four sections: Mathematical Usage (arithmetic, fractions, decimals, percentages, basic algebra, and applied calculations), Reading for Understanding (short passages followed by comprehension questions about utility work), Mechanical Concepts (understanding of pulleys, gears, levers, electrical principles, and mechanical systems), and Figural Reasoning (identifying patterns in diagrams). Most CAST prep courses and practice tests substitute number sequences for figural reasoning, since the underlying skill — pattern recognition — is the same and sequences require no diagrams.
How is the CAST scored?
The CAST produces a score on each section and a total score. Raw scores are typically converted to a standardized or percentile scale and combined with other hiring factors (interview score, experience, education) to produce an overall ranking. Because utilities often hire from the top of the list in ranked order, a higher score has direct, practical value — it can mean the difference between being hired in the current round or waiting for the next opening. There is no single universal passing score; the competitive threshold varies by utility and the size of the applicant pool.
How to prepare for the EEI CAST
Start with mathematical usage: drill fractions, percentages, ratios, and the power formula (P = V × I) until the mental math is fast and accurate — a calculator is not allowed. For reading comprehension, practice answering only from what the passage says, not from prior knowledge. For mechanical concepts, study pulley systems (mechanical advantage), transformer voltage and turns ratios, three-phase vs. single-phase power, and conductor sag behavior. For figural or sequence reasoning, practice number pattern questions (geometric, arithmetic, triangular, decreasing differences). Take timed practice tests to build pacing — each section has a strict time limit and finishing without guessing matters.
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Start the practice test →Frequently Asked Questions
How hard is the EEI CAST test?
The CAST is a competitive ranking exam, not a simple pass/fail. The math is applied rather than advanced — it requires reliable accuracy with fractions, percentages, and basic algebra under time pressure. The mechanical concepts section is the hardest for most applicants who have not studied electrical or mechanical principles before. Solid preparation typically takes two to four weeks.
Can I retake the EEI CAST if I do not score high enough?
Retake policies vary by utility. Some allow retakes after a waiting period (often 6 or 12 months); others allow only one attempt per job posting. Check the hiring policy of the specific utility before your test date, and treat every attempt as your best shot.
Is the EEI CAST the same as the IBEW aptitude test?
No — they are different tests from different organizations. The EEI CAST is used by investor-owned utilities for direct-hire apprenticeships. The IBEW/NJATC aptitude test is used by IBEW union locals for inside wireman apprenticeships. Some positions may involve both, but they are distinct exams with overlapping content areas.
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