Utah Master Electrician Rules and Laws Exam: Practice Test & Licensing Guide

A licensed journeyman electrician with no engineering degree or trade-school AAS degree wants to qualify for a Utah master electrician license through experience alone. How much work experience as a licensed journeyman electrician does the rule require?

Answer: At least 8,000 hours

Utah Code 58-55-302(3)(f)(iii) requires four years of practical experience as a journeyman electrician, and R156-55b-302a(1)(c) converts that path to at least 8,000 hours of work experience as a licensed journeyman electrician. 4,000 hours is the requirement for the AAS trade-school graduate path (R156-55b-302a(1)(b)), and 16,000 hours is the experience-only path to journeyman, not master.

Reference: Utah Admin. Code R156-55b, R156-55b-302a(1)(c)

A candidate has failed the master electrician law and rule exam for the seventh time. Under R156-55b, how long must the candidate wait before retaking it?

Answer: At least 120 days

R156-55b-302b(6) lets a candidate retake an exam no sooner than 30 days after a failure for up to six failures, and no sooner than 120 days after any failure after that. A seventh failure is past the sixth, so the 120-day wait applies. The 30-day wait covers only the first six failures.

Reference: Utah Admin. Code R156-55b, R156-55b-302b(6)

On a commercial (non-residential) project, how many licensed apprentice electricians may one licensed supervising electrician have under the rule?

Answer: Two

R156-55b-401(2)(a) allows a licensed supervisor up to two licensed apprentice electricians on a non-residential project. The limit of three applies only to residential projects (R156-55b-401(2)(b) and Utah Code 58-55-302(3)(j)(iv)).

Reference: Utah Admin. Code R156-55b, R156-55b-401(2)(a)

A commercial building service is supplied by one set of service-entrance conductors. Under the NEC 230.71 language Utah adopted by statute, what is the maximum number of switches or sets of circuit breakers that may serve as the service disconnecting means?

Answer: Six, and they may all be mounted in a single enclosure

Utah Code 15A-3-601(14) deletes NEC 2023 Section 230.71 and replaces it. The Utah text allows the service disconnecting means for each service to have not more than six switches or sets of circuit breakers, mounted in a single enclosure, in a group of separate enclosures, or in or on a switchboard or switchgear. The unamended 2023 NEC does not allow six disconnects in one enclosure, so this is a key Utah difference.

Reference: Utah Code, 15A-3-601(14)

Three continuous-duty, 460-volt, three-phase induction motors are on one feeder: 25 hp, 15 hp, and 10 hp. Using Table 430.250 full-load currents (34 A, 21 A, 14 A), what is the minimum feeder conductor ampacity under 430.24?

Answer: 77.5 A

430.24 requires feeder conductors to have an ampacity of at least 125% of the largest motor's full-load current plus the sum of the others. Use Table 430.250 values, not nameplate (430.6(A)(1)): 1.25 x 34 = 42.5 A; 42.5 + 21 + 14 = 77.5 A. Adding the currents without the 125% gives 69.0 A; multiplying the whole 69 A by 125% gives 86.3 A; applying 125% to the 15-hp motor instead of the largest gives 74.3 A.

Reference: NFPA 70, National Electrical Code, 2023, 430.24

A 75-kVA, three-phase transformer has a 480-volt primary and a 208Y/120-volt secondary and is protected on the primary side only (no secondary protection). What is the maximum standard-size primary overcurrent device permitted by Table 450.3(B)?

Answer: 125 A

Primary current = 75,000 / (1.732 x 480) = 90.2 A. With primary-only protection and a primary current of 9 A or more, Table 450.3(B) allows 125%: 90.2 x 1.25 = 112.8 A. Note 1 to the table allows the next higher standard size when 125% doesn't match a standard rating, so 125 A is permitted (240.6(A)). 110 A rounds down, 150 A is not permitted, and 225 A is based on the secondary current (208.2 A).

Reference: NFPA 70, National Electrical Code, 2023, Table 450.3(B), Note 1

Six current-carrying 3/0 AWG copper THHN conductors are installed in one raceway where the ambient temperature is 38 degrees C. Starting from the 90 degree C column of Table 310.16, what is the adjusted ampacity of each conductor?

Answer: 163.8 A

Table 310.16 gives 225 A for 3/0 Cu in the 90 degree C column. Table 310.15(C)(1) requires 80% for 4 to 6 current-carrying conductors, and Table 310.15(B)(1)(1) gives a correction factor of 0.91 for 36 to 40 degrees C in the 90 degree C column. 225 x 0.80 x 0.91 = 163.8 A. 180 A applies only the bundling factor, 204.8 A only the temperature factor, and 143.3 A wrongly uses the 70% factor for 7 to 9 conductors. The final ampacity must still be checked against terminal temperature limits (110.14(C)).

Reference: NFPA 70, National Electrical Code, 2023, Table 310.16; Table 310.15(B)(1)(1); Table 310.15(C)(1)

According to the hierarchy of risk control methods in NFPA 70E 110.3(H)(3), which method must be considered first?

Answer: Elimination

110.3(H)(3) requires risk control methods in this order: elimination, substitution, engineering controls, awareness, administrative controls, and PPE. PPE is the last line of defense. In electrical work, elimination usually means establishing an electrically safe work condition.

Reference: NFPA 70E, Standard for Electrical Safety in the Workplace, 2024, 110.3(H)(3)

Under NFPA 70E 110.4(A)(3), what is the maximum interval between retraining sessions in safety-related work practices for qualified employees?

Answer: 3 years

110.4(A)(3) requires additional training and retraining in safety-related work practices and applicable changes in the standard at intervals of no more than 3 years. Earlier retraining is required when supervision or annual inspections show noncompliance, when new equipment or procedures are introduced, when job duties change, or for tasks done less than once a year. (In the 2021 edition, training requirements were in 110.6; in 2024 they are in 110.4.)

Reference: NFPA 70E, Standard for Electrical Safety in the Workplace, 2024, 110.4(A)(3)

An electrical contractor's employee suffers a severe electrical burn on a Utah jobsite and is admitted to the hospital. Under Utah's occupational safety rule, how soon must the employer notify UOSH?

Answer: Within 8 hours of the occurrence

R614-1-5(B)(1) requires each employer to notify UOSH within 8 hours of any work-related fatality, any disabling, serious, or significant injury, and any occupational disease incident. R614-1-3(I) defines a disabling, serious, or significant injury to include hospital admission and electrical burns. Utah does not adopt the federal reporting times in 29 CFR 1904.39; R614-1-4(A)(1) excludes them in favor of the Utah rule.

Reference: Utah Admin. Code R614-1, R614-1-5(B)(1)