Download Nebraska Electrical Sign Exam Questions and Answers and more Exams Technology in PDF only on Docsity!
Question 1. Which Nebraska statute primarily governs the installation of electric signs? A) Nebraska Revised Statutes Chapter 75 B) Nebraska Electrical Act, Article 600 C) Nebraska State Electrical Division (NSED) Rules D) Nebraska Building Code, Chapter 12 Answer: B Explanation: The Nebraska Electrical Act incorporates NEC Article 600, which specifically addresses electric signs and outline lighting. Question 2. A sign installer must obtain a permit before which of the following actions? A) Purchasing sign components B) Performing a wiring inspection on a new sign C) Ordering a sign design D) Conducting a site survey Answer: B Explanation: Nebraska requires a permit and inspection for any new electrical work, including wiring of signs. Question 3. Under Nebraska law, how often must an electrical contractor renew their license? A) Every 2 years
B) Every 3 years C) Every 5 years D) Annually Answer: B Explanation: The Nebraska State Electrical Division mandates renewal every three years, with continuing‑education credits. Question 4. Which OSHA regulation applies to the use of ladders for sign installation? A) 1926. B) 1910. C) 1926. D) 1910. Answer: B Explanation: OSHA 1910.23 covers ladder safety for general industry, which includes sign work. Question 5. The primary purpose of a Lockout/Tagout (LOTO) procedure on a sign circuit is to: A) Reduce power consumption B) Prevent accidental energization while servicing C) Increase voltage output
Question 8. A sign operates on a 120 V, 60 Hz single‑phase AC supply. What is the frequency of the power? A) 50 Hz B) 60 Hz C) 120 Hz D) 240 Hz Answer: B Explanation: The frequency is explicitly given as 60 Hz. Question 9. Which type of power supply is most commonly used for LED channel letters? A) Neon transformer B) DC constant‑current driver C) AC‑DC LED driver (constant voltage) D) High‑frequency inverter Answer: C Explanation: LED drivers convert AC to regulated DC voltage for LEDs. Question 10. When calculating voltage drop for a sign branch circuit, which factor is NOT considered? A) Conductor length
B) Conductor resistance C) Load power factor D) Ambient temperature Answer: D Explanation: Ambient temperature affects ampacity, not the voltage‑drop calculation directly. Question 11. The ampacity of a copper conductor must be corrected for temperature using which NEC table? A) Table 310.15(B)(16) B) Table 300. C) Table 220. D) Table 110. Answer: A Explanation: Table 310.15(B)(16) provides temperature correction factors for conductors. Question 12. According to NEC, the maximum continuous load allowed on a branch circuit is what percentage of the breaker rating? A) 60 % B) 80 % C) 100 %
Question 15. Grounding conductors for signs must be identified by which color? A) White or gray B) Green or bare copper C) Red D) Black Answer: B Explanation: NEC requires grounding conductors to be green or bare. Question 16. The primary difference between grounding and bonding in sign installations is: A) Grounding carries current; bonding does not B) Grounding connects to earth; bonding joins conductive parts together to maintain the same potential C) Bonding is only for AC circuits D) Grounding is optional for signs Answer: B Explanation: Grounding provides a path to earth, while bonding ensures all metal parts share the same potential. Question 17. Which method is acceptable for protecting sign conductors from physical damage?
A) Running them through unprotected ducts B) Using metal conduit listed for outdoor use C) Exposing them on the sign surface D) Securing them with non‑metallic tape only Answer: B Explanation: Metal conduit provides mechanical protection and is permitted by NEC. Question 18. For a neon sign, the high‑voltage secondary conductor must be insulated with which minimum voltage rating? A) 600 V B) 1,000 V C) 1,500 V D) 2,500 V Answer: C Explanation: NEC 600.7 requires secondary conductors for neon to have a minimum 1,500 V rating. Question 19. The maximum allowable current for a single‑phase sign branch circuit is: A) 15 A B) 20 A
Explanation: NEC 600.7(A) mandates labeling the disconnect with its rating and identification as a sign circuit. Question 22. Which wiring method is permitted for interior sign wiring that is not exposed to the public? A) NM‑B cable (Romex) B) Flexible metal conduit (FMC) only C) Rigid metal conduit (RMC) only D) Any listed wiring method suitable for the environment Answer: D Explanation: NEC allows any listed method appropriate for the environment, provided it meets protection requirements. Question 23. When using flexible cord for a sign, the maximum length allowed without a listed extension cord is: A) 25 ft B) 50 ft C) 75 ft D) No specific limit, but must comply with voltage‑drop criteria Answer: D Explanation: NEC does not set a fixed length; the installer must ensure voltage drop and protection are acceptable.
Question 24. For outline lighting of a building, the conductors must be installed: A) Inside the building only B) In a raceway that is weatherproof where exposed C) Directly on the exterior surface without protection D) Only in underground conduit Answer: B Explanation: NEC 600.8 requires raceways for exterior outline lighting to be weatherproof. Question 25. A transformer supplying a sign must have overcurrent protection that is: A) The same rating as the transformer primary B) Not less than the transformer’s full‑load current C) 125 % of the transformer’s full‑load current D) 150 % of the transformer’s full‑load current Answer: C Explanation: NEC 600.9 requires overcurrent protection sized at 125 % of the transformer’s full‑load current. Question 26. When reading a sign blueprint, the symbol “⧈” typically denotes: A) A conduit run
D) Inside a warehouse with proper lighting Answer: A Explanation: NEC 600.11 restricts signs over sidewalks where they could impede pedestrian traffic. Question 29. The minimum size for a grounding electrode conductor for a sign with a 150 A service is: A) #12 AWG copper B) #10 AWG copper C) #8 AWG copper D) #6 AWG copper Answer: C Explanation: NEC Table 250.66 indicates #8 AWG for up to 200 A; #8 is the minimum for 150 A. Question 30. A sign’s secondary high‑voltage wiring must be bonded to: A) The building’s water pipe B) The sign’s metal frame C) The nearest telephone line D) No bonding required Answer: B
Explanation: NEC 600.12 requires bonding of high‑voltage secondary conductors to the sign’s metal parts. Question 31. Which of the following is considered a “readily accessible” disconnect for a sign? A) A pull‑type switch located behind a locked panel B) A surface‑mounted circuit breaker within 6 ft of the sign C) A remote switch located 30 ft away in a utility closet D) A concealed switch inside the sign’s internal wiring box Answer: B Explanation: Readily accessible means reachable without tools and within sight; a surface breaker meets this. Question 32. The NEC requires that sign circuits be protected by a fuse or breaker with a rating not exceeding: A) 125 % of the load B) 150 % of the load C) The ampacity of the smallest conductor D) The rating of the sign’s transformer Answer: C Explanation: Overcurrent devices must not exceed the ampacity of the conductors they protect (NEC 240.4).
B) Article 410 C) Article 600 D) Article 250 Answer: C Explanation: Article 600 contains the specific wiring requirements for signs. Question 36. The term “outline lighting” refers to: A) Interior illumination of a sign’s letters B) Lighting that follows the perimeter of a sign or building C) Backlighting of a sign panel D) Spotlights aimed at a sign Answer: B Explanation: Outline lighting is a continuous light source that follows the outline of a sign or structure. Question 37. For a sign that uses a neon transformer, the primary side must be protected by a fuse rated at: A) 125 % of the transformer’s primary current B) 80 % of the transformer’s primary current C) Exactly the transformer’s primary current D) No fuse is required on the primary side Answer: A
Explanation: NEC 600.9 requires primary overcurrent protection at 125 % of the transformer’s full‑load current. Question 38. Which of the following is a requirement for sign mounting brackets on a wall? A) Must be painted the same color as the wall B) Must be securely fastened to a structural element capable of supporting the sign’s weight C) Must be installed only with wood screws D) Must be hidden from view Answer: B Explanation: NEC and sign codes require brackets to be anchored to a structural member that can support the load. Question 39. When installing a sign on a roof, the required clearance from the roof edge to the nearest fire escape is: A) 2 ft B) 5 ft C) 10 ft D) No specific clearance required Answer: C Explanation: NEC 600.11 limits signs over fire escapes to a minimum 10‑ft clearance.
A) Inside the sign’s neon tubes B) In a location that provides easy access for maintenance C) Hidden behind drywall D) Mounted on the roof without a conduit Answer: B Explanation: NEC 600.9 requires power supplies to be accessible for service and maintenance. Question 43. If a sign circuit requires a 20 A breaker, the minimum conductor size (copper) is: A) #14 AWG B) #12 AWG C) #10 AWG D) #8 AWG Answer: B Explanation: NEC Table 310.15(B)(16) shows #12 AWG copper rated for 20 A at 60 °C. Question 44. The term “secondary conductor” in neon sign installations refers to: A) The low‑voltage wiring to the LEDs B) The high‑voltage wiring from the transformer to the tubes
C) The grounding wire D) The control wiring for dimming Answer: B Explanation: Secondary conductors carry the high voltage from the transformer to the neon tubes. Question 45. Which of the following is NOT a permissible method for supporting a sign’s conduit outdoors? A) Using listed conduit straps B) Hanging from a non‑metallic rope C) Securing to a metal support with proper clamps D) Embedding in concrete with listed fittings Answer: B Explanation: Non‑metallic rope is not an approved method for supporting conduit per NEC. Question 46. When a sign uses an LED driver with a built‑in overcurrent device, an additional circuit breaker is still required because: A) NEC requires dual protection for all signs B) The built‑in device may not meet the required rating for the branch circuit C) It is optional, not mandatory D) LED drivers never have overcurrent devices
