Download PrepIQ Iowa IA Sign Electrical Specialty Ultimate Exam and more Exams Technology in PDF only on Docsity!
Specialty Ultimate Exam
Question 1. What term describes the hollow glass tube that carries neon gas in a sign? A) LED module B) Skeleton tubing C) Fluorescent lamp D) Ballast Answer: B Explanation: Skeleton tubing is the glass conduit that contains the neon or other gases and defines the shape of the illuminated sign. Question 2. Which formula correctly expresses Ohm’s Law? A) V = I × R B) P = V ÷ I C) I = V ÷ P D) R = P ÷ I Answer: A Explanation: Ohm’s Law states that voltage (V) equals current (I) multiplied by resistance (R). Question 3. According to NEC, who has the final authority to approve sign installations? A) Manufacturer B) Electrical Engineer C) Authority Having Jurisdiction (AHJ) D) Sign Designer Answer: C Explanation: The AHJ enforces code compliance and can approve or reject installations. Question 4. What characteristic defines “workmanlike” installation for electrical signs? A) Use of the cheapest materials B) Neat, secure, and code-compliant connections C) Installation in the shortest time possible D) All of the above Answer: B Explanation: Workmanship requires neat, secure, and code-compliant practices, not simply speed or cost. Question 5. Which conduit is most appropriate for outdoor sign raceways that require corrosion resistance? A) EMT B) Rigid Metal Conduit (RMC) C) PVC conduit D) Flexible metal conduit Answer: C Explanation: PVC conduit is non-metallic, resistant to corrosion, and suitable for outdoor environments.
Specialty Ultimate Exam
Question 6. What is the typical color code for a grounded (equipment grounding) conductor in the United States? A) Black B) Red C) Green or bare D) White Answer: C Explanation: Green or bare conductors are used for equipment grounding per NEC. Question 7. When sizing a pull box for a sign circuit, which factor is NOT considered? A) Number of conductors B) Conductor size C) Ambient temperature D) Sign’s visual design Answer: D Explanation: Electrical sizing concerns conductors, temperature, and number of wires, not aesthetic design. Question 8. **How must cable be secured to a sign frame according to NEC 300.11? ** A) Every 6 ft or less B) Every 12 ft or less C) Only at terminations D) No securing required for flexible cable Answer: A Explanation: Cables must be supported and secured at intervals not exceeding 6 ft. Question 9. A sign requires a total load of 2,400 VA on a 120 V system. What is the minimum ampacity of the branch circuit required? A) 10 A B) 15 A C) 20 A D) 30 A Answer: C Explanation: 2,400 VA ÷ 120 V = 20 A. NEC requires at least a 20-ampere branch circuit for sign loads. Question 10. Which overcurrent protective device is appropriate for a 12 AWG copper conductor feeding a sign? A) 15 A fuse B) 20 A circuit breaker C) 30 A breaker D) 40 A fuse Answer: B Explanation: 12 AWG copper is rated for 20 A; a 20 A breaker matches the conductor rating. Question 11. Where must a sign disconnect be installed to satisfy NEC 600.12? A) Inside the sign enclosure B) At the nearest ceiling C) Within sight of the sign and readily accessible D) In a remote electrical room
Specialty Ultimate Exam
Explanation: A ballast limits current and provides the appropriate voltage for neon tubes. Question 17. LED signs powered from a Class 2 power source must not exceed what maximum voltage? A) 30 V B) 60 V C) 100 V D) 150 V Answer: B Explanation: Class 2 sources are limited to 60 V rms or 30 V dc to reduce shock hazard. Question 18. What is the required minimum vertical clearance between a sign and a window opening in a public building? A) 24 in B) 30 in C) 36 in D) 48 in Answer: C Explanation: NEC 600.21 mandates a minimum of 36 in vertical clearance to prevent glare and fire hazards. Question 19. Portable signs that are cord-connected must have a plug that is rated for at least what amperage? A) 5 A B) 10 A C) 15 A D) 20 A Answer: C Explanation: A 15 A plug is the standard minimum for cord-connected portable signage to handle typical loads. Question 20. When installing a sign near a fuel dispensing station, which classification must the equipment meet? A) Class I, Division 2 B) Class III, Division 1 C) Class I, Division 1 D) Class II, Division 2 Answer: C Explanation: Signs in hazardous (fuel) locations must be rated Class I, Division 1 to prevent ignition of flammable vapors. Question 21. What type of enclosure is required for a sign installed in a damp location? A) Open frame B) Non-weather-proof metal box C) NEMA 3R rated enclosure D) NEMA 1 rated box Answer: C Explanation: NEMA 3R enclosures protect against rain and moisture, suitable for damp locations.
Specialty Ultimate Exam
Question 22. Sign installations near swimming pools must maintain a minimum distance of how many inches from the water’s edge? A) 12 in B) 18 in C) 24 in D) 36 in Answer: C Explanation: NEC 680.23 requires a minimum 24 in separation to reduce shock risk. Question 23. Which OSHA standard applies to ladder safety when installing signs at heights greater than 6 ft? A) 1910.23 B) 1910.24 C) 1910.25 D) 1910. Answer: A Explanation: OSHA 1910.23 covers ladder safety, including requirements for height, inspection, and use. Question 24. When working on a live neon sign, the minimum PPE required includes which of the following? A) Safety glasses only B) Insulated gloves and safety glasses C) Hard hat only D) No PPE if voltage is below 120 V Answer: B Explanation: Insulated gloves protect against high voltage; safety glasses guard against glass breakage. Question 25. What instrument is used to verify the continuity of a sign’s grounding path? A) Clamp meter B) Insulation resistance tester C) Multimeter set to continuity D) Voltage detector pen Answer: C Explanation: A multimeter on continuity mode checks for a low-resistance path, confirming proper grounding. Question 26. If a sign’s voltage drop exceeds 3 % on a 100-ft run, what corrective action is recommended? A) Increase conduit size B) Use a higher-rated transformer C) Reduce the load D) Add a second circuit Answer: A Explanation: Increasing conductor size reduces resistance, lowering voltage drop.
Specialty Ultimate Exam
Question 32. What is the minimum insulation rating for conductors used in a sign’s high-voltage (line) circuit? A) 300 V B) 600 V C) 1 kV D) 2 kV Answer: B Explanation: NEC requires at least 600 V rated insulation for circuits up to 600 V. Question 33. Which calculation determines the required size of a grounding electrode conductor for a sign? A) VA ÷ Voltage B) Ampacity × Length C) Table 250.66 D) Table 310. Answer: C Explanation: Table 250.66 of the NEC provides the minimum size based on the size of the service or feeder. Question 34. In a sign installation, what is the purpose of a “pull box”? A) To house the transformer B) To provide a junction point for conductors C) To mount the sign D) To act as a ground rod Answer: B Explanation: Pull boxes allow conductors to be spliced, pulled, and routed without strain. Question 35. Which NEC rule governs the use of flexible metal conduit (FMC) for sign wiring? A) 340.10 B) 358.10 C) 352.10 D) 376. Answer: B Explanation: Article 358 covers Flexible Metal Conduit (FMC) and its permitted uses. Question 36. A sign’s neon tubing is 150 ft long and draws 0.5 A at 12 kV. What is the approximate VA of the sign? A) 6 VA B) 60 VA C) 600 VA D) 6,000 VA Answer: D Explanation: VA = V × I = 12,000 V × 0.5 A = 6,000 VA. Question 37. What is the required minimum distance between a sign and a fire escape door according to NEC 600.21? A) 12 in B) 24 in C) 36 in D) 48 in Answer: C
Specialty Ultimate Exam
Explanation: NEC mandates a 36 in clearance to prevent obstruction and fire spread. Question 38. When a sign is installed on a metal pole, which grounding method is acceptable? A) No grounding required B) Ground the pole to the building electrode C) Use a separate ground rod D) Bond the pole to the sign frame only Answer: B Explanation: The metal pole must be bonded to the building’s grounding electrode system to ensure a continuous low-impedance path. Question 39. Which of the following is a permitted conductor insulation type for interior sign wiring? A) XHHW-2 B) THHN C) NM-B D) All of the above Answer: D Explanation: All listed insulation types are allowed for interior wiring, provided they meet temperature and voltage ratings. Question 40. What is the maximum allowed length of a flexible cord used to power a portable sign without a listed extension? A) 25 ft B) 50 ft C) 75 ft D) No limit if rated 15 A Answer: B Explanation: NEC 400.5 limits flexible cord length for portable equipment to 50 ft unless a listed extension is used. Question 41. Which NEC article addresses the installation of signs in wet locations? A) 300.5 B) 600.7 C) 410.10 D) 680. Answer: B Explanation: Article 600.7 specifically deals with signs in wet or damp locations. Question 42. A sign’s transformer is rated 120 V primary, 12 V secondary, 200 VA. What is the minimum size of the secondary conductors? A) 14 AWG B) 12 AWG C) 10 AWG D) 8 AWG Answer: B Explanation: 200 VA ÷ 12 V = 16.7 A; 12 AWG copper is rated for 20 A, satisfying the requirement.
Specialty Ultimate Exam
Question 48. Which NEC rule dictates that a sign’s disconnecting means must be lockable? A) 210.8 B) 600.12 C) 300.3 D) 110. Answer: B Explanation: Article 600.12 requires disconnects to be readily accessible and lockable. Question 49. For a sign located in a Class I, Division 2 hazardous area, which type of conduit is required? A) PVC B) Rigid metal conduit with gasketed fittings C) EMT D) Flexible metal conduit Answer: B Explanation: Rigid metal conduit with gasketed fittings provides the necessary protection in hazardous environments. Question 50. What is the permissible voltage for a sign’s low-voltage lighting circuit under NEC 410.16? A) 30 V B) 60 V C) 120 V D) 150 V Answer: B Explanation: NEC 410.16 limits low-voltage lighting circuits to 60 V. Question 51. **A sign’s neon tubes are installed 8 ft above a public walkway. What is the minimum required clearance from the top of the sign to the walkway ceiling? ** A) 6 ft B) 8 ft C) 10 ft D) 12 ft Answer: B Explanation: NEC 600.21 requires a minimum of 8 ft clearance for signs above walkways. Question 52. **Which of the following is a required marking on a sign’s transformer? ** A) Manufacturer’s logo B) Voltage rating C) Color of the sign D) Installation date Answer: B Explanation: NEC requires voltage and rating information to be clearly marked on transformers. Question 53. When using EMT for a sign raceway, what is the maximum allowable bend radius? A) 2 × conduit diameter B) 3 × conduit diameter C) 4 × conduit diameter D) 5 × conduit diameter
Specialty Ultimate Exam
Answer: B Explanation: EMT must be bent with a radius not less than three times its diameter to avoid damage. Question 54. What is the purpose of a “ground-fault circuit interrupter” (GFCI) on a sign installed near a pool? A) To improve illumination B) To protect against electrical shock C) To reduce power consumption D) To regulate voltage Answer: B Explanation: GFCIs detect ground faults and quickly disconnect power, preventing shock hazards near water. Question 55. Which NEC table is used to determine the required conduit fill for sign wiring? A) Table 310.15 B) Table 300.5 C) Table 1, Chapter 9 D) Table 1, Chapter 3 Answer: D Explanation: Table 1, Chapter 3 provides conduit fill percentages for various conductor sizes. Question 56. A sign’s power supply is listed as “UL 1449”. What does this indicate? A) It is a Class 2 device B) It meets surge protective device standards C) It is approved for hazardous locations D) It is a fire-rated enclosure Answer: B Explanation: UL 1449 is the standard for Surge Protective Devices. Question 57. When a sign is installed on a roof, which of the following is required for the supporting structure? A) Only a stainless-steel bracket B) A structural engineer’s approval C) A non-metallic hanger D) No special requirement if the sign is lightweight Answer: B Explanation: Roof-mounted signs must be supported by a structure capable of bearing the load; an engineer’s approval ensures compliance. Question 58. Which NEC article governs the installation of signs in swimming pool areas? A) 680.23 B) 300.5 C) 410.10 D) 600.
Specialty Ultimate Exam
Answer: A Explanation: NEMA 4X provides protection against corrosion, dust, and water, suitable for harsh industrial settings. Question 64. When a sign’s neon tubing is repaired, which safety precaution is mandatory? A) Turn off only the ballast B) De-energize the entire sign circuit and lock out/tag out C) Wear only safety glasses D) No special precaution if the tube is low voltage Answer: B Explanation: Lockout/tagout ensures the circuit cannot be re-energized while work is performed. Question 65. What is the required labeling for a sign’s branch circuit panel? A) “Sign Power” B) “Lighting” C) “General Use” D) Any label is acceptable Answer: A Explanation: NEC requires clear identification; “Sign Power” directly indicates the circuit’s purpose. Question 66. A sign’s LED driver draws 2 A at 24 V. What is the VA of the LED load? A) 24 VA B) 48 VA C) 96 VA D) 120 VA Answer: B Explanation: VA = V × I = 24 V × 2 A = 48 VA. Question 67. Which NEC article specifies the minimum distance between a sign and a fire-sprinkler head? A) 300.21 B) 600.21 C) 680.23 D) 210. Answer: B Explanation: Article 600.21 includes clearances from fire protection devices. Question 68. When installing a sign in a location with a temperature rating of 50 °C, which conductor insulation must be used? A) 60 °C rated B) 75 °C rated C) 90 °C rated D) Any rating is acceptable Answer: B
Specialty Ultimate Exam
Explanation: Conductors must have an insulation rating equal to or greater than the ambient temperature; 75 °C is the next standard rating above 50 °C. Question 69. What is the purpose of a “neutral grounding resistor” in a sign’s power system? A) To limit fault current B) To increase illumination C) To balance voltage D) To reduce harmonic distortion Answer: A Explanation: A neutral grounding resistor limits fault current to safe levels. Question 70. Which NEC rule requires that sign wiring be protected from physical damage when installed in a wall cavity? A) 300.4 B) 300.11 C) 300.15 D) 300. Answer: A Explanation: NEC 300.4 mandates protection of conductors from physical damage, often by using conduit or raceway in wall cavities. Question 71. A sign’s transformer is listed for indoor use only. What must be done to install it outdoors? A) No action; it can be used outdoors B) Install it in a NEMA 4 enclosure C) Replace it with an outdoor-rated transformer D) Paint it with waterproof coating Answer: C Explanation: Transformers must be listed for the environment of installation; an indoor-rated unit cannot be used outdoors. Question 72. What is the minimum distance between a sign and a doorway swing space according to NEC 600.21? A) 12 in B) 24 in C) 36 in D) 48 in Answer: C Explanation: A 36 in clearance ensures that the sign does not obstruct door operation or create fire hazards. Question 73. Which of the following is a permitted method for terminating a sign’s conductors in a junction box? A) Twist-on wire nuts only B) Crimp connectors only C) Soldered splices only D) Any listed connector method Answer: D
Specialty Ultimate Exam
Question 79. When a sign’s transformer is installed in a ceiling cavity, what must be provided for heat dissipation? A) A vented cover B) A thermal fuse C) A metal heat sink D) No additional provision is required if listed Answer: A Explanation: NEC requires that heat-producing equipment in concealed spaces have adequate ventilation. Question 80. Which of the following is NOT a recognized hazard class for signs in NEC? A) Class I B) Class II C) Class III D) Class IV Answer: D Explanation: NEC defines Classes I, II, and III for hazardous locations; there is no Class IV for signs. Question 81. What is the required minimum rating for a disconnecting means that serves a 2 kVA sign circuit? A) 15 A B) 20 A C) 30 A D) 40 A Answer: C Explanation: 2 kVA at 120 V equals 16.7 A; a 30 A disconnect provides adequate rating and meets the 125 % rule. Question 82. Which NEC article specifies the grounding requirements for sign frames that are not part of the building structure? A) 250.130 C) 250.104 B) 250.148 D) 250. Answer: C Explanation: NEC 250.130(C) addresses grounding of equipment not permanently attached to the grounding electrode system. Question 83. A sign uses a 24 V LED driver. According to NEC, this driver is considered a: A) Class 1 power source B) Class 2 power source C) Class 3 power source D) Not classified Answer: B Explanation: Voltage ≤ 60 V rms qualifies the driver as a Class 2 source.
Specialty Ultimate Exam
Question 84. What is the minimum clearance required between a sign and a sprinkler head when the sign is mounted on a wall? A) 12 in B) 18 in C) 24 in D) 30 in Answer: C Explanation: NEC 600.21 mandates at least 24 in clearance to avoid interference with fire suppression. Question 85. Which type of conduit is prohibited for use in a sign installation that passes through a hazardous (Class I) area? A) Rigid metal conduit B) PVC conduit C) EMT D) Flexible metal conduit with gasketed fittings Answer: B Explanation: PVC is not permitted in Class I hazardous locations because it cannot provide the required protection. Question 86. When a sign is powered by a 120 V/20 A circuit, what is the maximum allowable continuous load per NEC 210.20(A)? A) 12 A B) 16 A C) 18 A D) 20 A Answer: B Explanation: Continuous loads must not exceed 80 % of the breaker rating: 0.8 × 20 A = 16 A. Question 87. What does the NEC term “listed” signify for a sign component? A) It has been approved by the manufacturer B) It meets UL or equivalent testing standards C) It is made of stainless steel D) It is user-installed only Answer: B Explanation: “Listed” means the product has been evaluated and approved by a recognized testing agency such as UL. Question 88. A sign’s neon tubing requires a ballast that limits current to 0.2 A. Which device rating is appropriate for this ballast? A) 0.1 A B) 0.2 A C) 0.5 A D) 1 A Answer: C Explanation: The ballast must be rated equal to or greater than the required current; 0.5 A provides a safe margin.
Specialty Ultimate Exam
Answer: C Explanation: In parallel, the total current is the sum of each branch: 0.5 A × 4 = 2 A. Question 94. Which NEC article addresses the installation of signage in aircraft hangars? A) 500.13 B) 600.8 C) 410.10 D) 590. Answer: B Explanation: Article 600.8 includes special provisions for signs in aircraft hangars. Question 95. When a sign is installed near a fire escape, what is the required minimum horizontal clearance? A) 12 in B) 18 in C) 24 in D) 30 in Answer: C Explanation: NEC 600.21 requires at least 24 in horizontal clearance from fire escapes. Question 96. Which of the following is a correct method for identifying a sign’s neutral conductor? A) White or gray insulation B) Black insulation C) Green insulation D) Bare copper Answer: A Explanation: Neutral conductors are identified by white or gray insulation per NEC. Question 97. What is the required protection for a sign’s wiring that passes through a concrete floor slab? A) No protection needed B) Use of conduit or raceway C) Only a protective cover D) PVC conduit only Answer: B Explanation: Conductors passing through slabs must be protected by conduit or a raceway to prevent damage. Question 98. Which NEC table provides the allowable ampacity for a 14 AWG copper conductor in a 75 °C environment? A) Table 310.15(B)(16) B) Table 310. C) Table 310.13 D) Table 310. Answer: A Explanation: Table 310.15(B)(16) lists ampacities for various conductor sizes and temperature ratings.
Specialty Ultimate Exam
Question 99. A sign’s transformer is installed in a location with a maximum ambient temperature of 40 °C. Which conductor insulation rating is the minimum acceptable? A) 60 °C B) 75 °C C) 90 °C D) 105 °C Answer: B Explanation: Conductors must be rated for at least the ambient temperature; 75 °C is the next standard rating above 40 °C. Question 100. When a sign is powered by a 240 V transformer, what type of disconnect is required by NEC 600.12? A) Single-pole breaker B) Two-pole breaker C) Fuse only D) No disconnect required Answer: B Explanation: A two-pole disconnect is required for 240 V circuits to simultaneously open both ungrounded conductors. Question 101. What is the minimum distance between a sign’s neon tubing and a combustible ceiling? A) 12 in B) 18 in C) 24 in D) 30 in Answer: C Explanation: NEC 600.21 specifies a 24 in clearance from combustible ceilings to neon tubing. Question 102. Which of the following is a permitted grounding method for a metal sign enclosure that is not attached to a grounded structure? A) Ground rod at the base B) Bonding to the nearest water pipe C) Using a listed grounding strap to the building ground D) No grounding required if the sign is low voltage Answer: C Explanation: A listed grounding strap connecting the enclosure to the building’s grounding system satisfies NEC requirements. Question 103. A sign’s wiring must be protected from physical damage in a commercial building. Which of the following meets NEC 300.4(A) requirements? A) Running the conductors loose inside the wall cavity B) Installing the conductors in EMT conduit C) Using only NM cable D) Stretching the wires across the ceiling Answer: B
