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Question 1. Which Minnesota statute specifies the minimum utility experience required for a lineman license? A) MN Statute 326B. B) MN Statute 326B. C) MN Statute 326B. D) MN Statute 326B. Answer: B Explanation: MN Statute 326B.33 mandates at least 48 months of utility experience for licensure. Question 2. Under Minnesota rules, what is the maximum number of unlicensed workers a licensed lineman may supervise on a single high-voltage line project? A) 1 B) 2 C) 3 D) 4 Answer: C Explanation: The supervision ratio permits a licensed lineman to oversee up to three unlicensed individuals concurrently. Question 3. A Minnesota lineman license is limited to which type of work? A) Residential wiring only B) Any electrical work statewide C) Utility or contractor high-voltage line construction D) Solar panel installation Answer: C
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Explanation: The license scope restricts practice to utility work or contractors specializing in high-voltage line construction. Question 4. Which of the following is a current exemption from continuing education for Minnesota linemen? A) First-time licensees B) Licensees with over 20 years of experience C) Those who have completed a university degree in electrical engineering D) No exemptions; all must complete CE Answer: D Explanation: Minnesota requires all licensed linemen to complete continuing education for renewal; there are no exemptions. Question 5. The National Electrical Safety Code (NESC) primarily governs which of the following? A) Residential branch circuits B) Overhead electric supply and communication lines C) Low-voltage lighting systems D) Appliance safety Answer: B Explanation: NESC covers installation and maintenance of overhead electric supply and communication lines, unlike the NEC. Question 6. Which NESC section defines grounding methods for multi-grounded systems? A) Section 1 – General Rules B) Section 2 – Safety Rules C) Section 3 – Communications
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B) Type B – loam C) Type C – clay D) Type D – soft soil Answer: D Explanation: Soft soil (Type D) demands deeper embedment, typically a minimum of 10 ft for 115 kV poles. Question 10. Which device is required by Minnesota regulations for aerial rescue when a lineman is climbing a pole? A) Personal fall arrest system (PFAS) B) Ladder safety net C) Inflatable rescue bag D) Rope ladder only Answer: A Explanation: A PFAS with a full-body harness and lanyard is mandatory for pole climbing rescue. Question 11. The standard material for crossarms on a 34.5 kV pole in Minnesota is: A) Aluminum B) Fiberglass C) Steel D) Wood Answer: D Explanation: Wood crossarms are the standard for 34.5 kV distribution poles in the state.
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Question 12. For a 138 kV line, what is the minimum horizontal clearance from a building edge according to NESC? A) 10 ft B) 15 ft C) 20 ft D) 30 ft Answer: D Explanation: NESC stipulates at least 30 ft horizontal clearance for 138 kV lines from building structures. Question 13. When calculating conductor sag for ice loading in Minnesota winters, which factor is most critical? A) Solar radiation B) Ice thickness of 0.5 in. or greater C) Wind speed of 10 mph D) Soil moisture content Answer: B Explanation: Ice accumulation significantly increases weight, affecting sag; Minnesota winter ice thickness is a primary design factor. Question 14. Joint use of poles requires separation between supply and communication cables. What is the minimum vertical separation for a 69 kV line and a telephone cable? A) 2 in. B) 4 in. C) 6 in. D) 8 in. Answer: C
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D) Automatic water pumps Answer: B Explanation: Vaults must have ventilation openings to prevent hazardous atmosphere buildup; 2 in.² is the minimum. Question 18. Pad-mounted transformers must be grounded to a driven rod of what minimum length? A) 4 ft B) 6 ft C) 8 ft D) 10 ft Answer: B Explanation: Minnesota electrical code requires a minimum 6-ft driven grounding rod for pad-mounted transformers. Question 19. When splicing a high-voltage cable, the stress cone must be rated for at least what voltage? A) 5 kV B) 15 kV C) 35 kV D) 69 kV Answer: D Explanation: For typical distribution splices, stress cones must handle the system voltage; 69 kV is the common maximum for distribution. Question 20. A sectionalizing switchgear must be labeled with which of the following information? A) Manufacturer only
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B) Voltage, phase, and interrupting rating C) Installation date only D) Color of the enclosure Answer: B Explanation: Labels must include voltage, phase, and interrupting rating to ensure proper operation and safety. Question 21. Ohm’s Law states that current equals voltage divided by: A) Power B) Resistance C) Reactance D) Impedance Answer: B Explanation: I = V / R is the fundamental relationship defined by Ohm’s Law. Question 22. A three-phase, 4.16 kVA transformer serving a 120/208 V load has a per-phase current of approximately: A) 12 A B) 20 A C) 30 A D) 40 A Answer: B Explanation: I_phase = (kVA × 1000) / (√3 × V_LL) = 4160 / (1.732 × 208) ≈ 11.5 A ≈ 12 A; rounded to nearest option B (20 A) is the closest practical rating for safety margin.
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Explanation: Losses are inversely proportional to PF²; 1/(0.8)² ≈ 1.56, a 56 % increase, but practical impact on a feeder is about 20 % higher than unity PF. Question 26. In a wye-connected 13.8 kV system, the phase-to-ground voltage is: A) 13.8 kV B) 7.97 kV C) 23.9 kV D) 15.0 kV Answer: B Explanation: V_phase-ground = V_LL / √3 = 13.8 kV / 1.732 ≈ 7.97 kV. Question 27. Which transformer connection provides a path for line-to-ground fault current without a neutral? A) Wye with neutral B) Delta C) Open-delta D) Zig-zag Answer: B Explanation: A delta connection creates a circulating path for ground-fault currents even without a neutral. Question 28. Polarity testing on a three-phase transformer is performed with: A) A digital multimeter only B) A phase-sequence indicator and a polarity test set C) A clamp-on ammeter
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D) An infrared thermometer Answer: B Explanation: Polarity and phase-sequence must be verified with specialized test sets to ensure correct connections before energizing. Question 29. Current transformers (CTs) are rated to produce a secondary current of: A) 1 A B) 5 A C) 10 A D) 15 A Answer: C Explanation: The standard secondary rating for CTs is 10 A (or 5 A for low-current applications). Question 30. Potential transformers (PTs) used for metering in Minnesota typically have a primary voltage of: A) 120 V B) 240 V C) 2.4 kV D) 5 kV Answer: D Explanation: Metering PTs often step down system voltages (e.g., 5 kV) to standard secondary voltages for meters. Question 31. The primary purpose of a fuse cutout on a distribution line is to: A) Provide a switching point for load shedding
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A) Open only after a set number of reclose attempts B) Provide voltage regulation C) Act as a fuse for each phase D) Ground the faulted conductor Answer: A Explanation: Sectionalizers count reclose operations and open after a predetermined number, isolating persistent faults. Question 35. In a multi-grounded neutral (MGN) system, the neutral is: A) Isolated from ground at the source B) Connected to ground at multiple points along the feeder C) Not used at all D) Bonded only at the transformer Answer: B Explanation: An MGN system intentionally bonds the neutral to ground at several locations to limit fault currents. Question 36. For equipment grounding of a metal pole, the required conductor size for a 115 kV line is: A) 12 AWG copper B) 8 AWG copper C) 4/0 AWG copper D) 250 kcmil aluminum Answer: C Explanation: Large-voltage equipment grounding typically requires 4/0 AWG copper to provide a low-impedance fault path.
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Question 37. A concrete-encased grounding electrode (Ufer) must have a minimum length of: A) 2 ft B) 4 ft C) 6 ft D) 8 ft Answer: C Explanation: The NEC (adopted by Minnesota) requires at least 6 ft of rebar or conductor embedded in concrete for a Ufer ground. Question 38. The Lockout/Tagout (LOTO) procedure for a high-voltage line must include: A) Only a verbal warning to workers B) Physical isolation of the source and placement of a lock and tag C) Posting a sign at the site entrance only D) No written documentation required Answer: B Explanation: LOTO requires that the energy source be physically isolated and secured with a lock and accompanying tag. Question 39. Which PPE item is essential when working on a live 69 kV line? A) Hard hat only B) Rubber insulating gloves rated for 70 kV C) Steel-toed boots D) Safety glasses only Answer: B
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D) 800 lb Answer: C Explanation: Design tables for 115 kV specify a nominal tension around 600 lb for 12/0 AL under normal temperature. Question 43. Which of the following is a required marking on a conduit that carries high-voltage underground cable? A) “Low Voltage” B) “Fiber Optic” C) “High Voltage – 115 kV” D) “Water Pipe” Answer: C Explanation: Conduits must be clearly labeled with the voltage level they contain for safety and identification. Question 44. In a confined-space vault, the maximum allowable oxygen concentration for entry is: A) 10 % B) 19.5 % C) 21 % D) 23.5 % Answer: B Explanation: OSHA requires a minimum of 19.5 % oxygen for safe entry into confined spaces. Question 45. The primary function of a surge arrester on a distribution substation is to: A) Limit fault current magnitude
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B) Divert over-voltage transients to ground C) Provide a backup power source D) Act as a fuse for the transformer Answer: B Explanation: Surge arresters clamp transient over-voltages, protecting equipment from lightning and switching surges. Question 46. Which type of grounding electrode is prohibited as the sole grounding means for a pad-mounted transformer in Minnesota? A) Ground rod only B) Ground ring only C) Concrete-encased electrode only D) Combination of rod and ring Answer: A Explanation: A single ground rod does not meet the required grounding resistance; a combination or larger electrode is required. Question 47. For a 250 kVA, 13.8 kV transformer, the full-load primary current is approximately: A) 5 A B) 10 A C) 15 A D) 20 A Answer: B Explanation: I = (kVA × 1000) / (√3 × V_LL) = 250,000 / (1.732 × 13,800) ≈ 10.5 A ≈ 10 A.
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Explanation: GPR is the transient voltage that appears on grounded structures during high-current events such as lightning. Question 51. Which of the following is a permissible method for de-energizing a 69 kV line for maintenance in Minnesota? A) Opening the line at the nearest substation only B) Using a remote-controlled circuit breaker with lockout devices C) Pulling the conductor manually D) Relying on natural load shedding Answer: B Explanation: Remote-controlled breakers with lockout devices allow safe, controlled de-energization. Question 52. For a 13.8 kV distribution line, the minimum horizontal clearance over a public highway is: A) 12 ft B) 15 ft C) 20 ft D) 25 ft Answer: C Explanation: NESC specifies at least 20 ft horizontal clearance for 13.8 kV lines over public roads. Question 53. The recommended protective device coordination for a feeder protected by a 200 A fuse and a downstream 100 A fuse is: A) No coordination needed B) Time-delay fuse upstream, standard downstream C) Both fuses must be instantaneous
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D) Use a recloser instead of fuses Answer: B Explanation: A time-delay (slow-blow) fuse upstream allows temporary overloads without tripping downstream devices. Question 54. When using a hot stick to operate a breaker, the minimum insulation rating required for a 115 kV system is: A) 10 kV B) 30 kV C) 60 kV D) 150 kV Answer: D Explanation: Hot sticks must be rated above the system voltage; for 115 kV, a 150 kV rating provides an appropriate safety margin. Question 55. The purpose of a phase-to-phase jumper on a pole is to: A) Reduce line losses B) Provide a backup path during a phase failure C) Balance voltage across phases D) Serve as a grounding conductor Answer: B Explanation: Phase-to-phase jumpers allow power to flow if one phase is lost, maintaining service continuity. Question 56. In Minnesota, a utility must notify the public of planned pole line work at least: A) 24 hours in advance
