eep April 10, 2025 NEC 400-490 NEC Quizzes Report a question What’s wrong with this question? You cannot submit an empty report. Please add some details. 0% Article 400-490 Part02 This quiz consists of 50 carefully selected questions covering NEC Articles 400 through 490, which provide critical guidelines for flexible cords and cables (Article 400), switchgear and control equipment (Article 409), and installations operating above 1000 volts (Article 490). These sections of the National Electrical Code focus on safety, material specifications, and proper installation practices. The randomly generated questions ensure a thorough assessment of your understanding, reinforcing key principles related to permitted uses of flexible cords, ampacity ratings, industrial control panels, and high-voltage equipment requirements. Some topics may reappear in different contexts to strengthen comprehension and application. Your feedback is invaluable! If you notice any discrepancies or have suggestions for improvement, please report them. Your insights help maintain the accuracy and effectiveness of this learning tool. All motor windings require proper protection. 1 / 50 How must part-winding motors be protected (430.4)? a. No protection is required. b. Protection is optional for dual-winding motors. c. Only one winding needs protection. d. Each winding must be individually protected. Incorrect. Individual protection for each winding is mandatory. Correct! Each winding must be individually protected. Each winding of a part-winding motor must have branch-circuit short-circuit and ground-fault protection at half the specified trip current. Sizing must account for continuous operation. 2 / 50 How must branch-circuit conductors for a single motor-compressor be sized (440.32)? a. At 125% of the rated-load current. b. Based on the locked-rotor current. c. At 150% of the full-load current. d. At 100% of the rated-load current. Incorrect. The correct value is 125% of the rated-load current. Correct! Conductors must be sized for 125% of the load. Branch-circuit conductors must be sized at 125% of the motor-compressor’s rated-load current to handle continuous operation without overheating. Proper connectors ensure safe and durable connections. 3 / 50 What must be provided for the electrical connections of embedded heating elements (426.24)? a. Temporary splices are allowed. b. Connections require only wire nuts. c. Insulated connectors identified for the use. d. Connections can be made without a box. Incorrect. NEC mandates the use of identified insulated connectors. Correct! Insulated connectors identified for the use are required. Electrical connections for embedded heating elements must use insulated connectors that are specifically identified for this application, ensuring safety and compliance. This article focuses on heating systems for industrial applications. 4 / 50 What type of equipment is covered under NEC Article 427 (427.1)? a. Residential heating systems. b. Portable heaters for industrial use. c. Electrically energized heating systems for pipelines and vessels. d. Emergency heating systems only. Incorrect. This article specifically covers industrial heating systems for pipelines and vessels. Correct! Article 427 is for heating systems used with pipelines and vessels. Article 427 applies to electrically energized heating systems used with pipelines and vessels, including resistance, impedance, induction, and skin-effect heating. Integral thermal protection doesn’t eliminate other requirements. 5 / 50 How must motors with integral thermal protection be installed (430.32(D))? a. They must comply with manufacturer specifications and NEC requirements. b. With protection provided at the service panel. c. Without additional overcurrent devices. d. Using external temperature sensors only. Incorrect. Integral protection alone is not sufficient without NEC compliance. Correct! NEC and manufacturer requirements must be followed. Motors with integral thermal protection must still follow manufacturer guidelines and NEC requirements for safe operation. Grounding ensures the motor’s safe operation. 6 / 50 What type of grounding must be provided for motor terminal housings (430.12(E))? a. Direct connection to the motor frame. b. Means for grounding connections inside or outside the housing. c. Only external grounding. d. Grounding is not required for motors under 1 HP. Incorrect. Grounding means must be present in terminal housings. Correct! Grounding means are required for safety. Motor terminal housings must include a grounding means, which can be located either inside or outside the housing, ensuring safe operation. Capacitor conductors have unique sizing criteria. 7 / 50 How must capacitor conductors for motors be sized (430.83)? a. Equal to or greater than 135% of the capacitor current. b. At 150% of motor full-load current. c. By matching the service conductor ampacity. d. At 125% of total connected motor loads. Incorrect. Capacitor conductors require a minimum size of 135% of current. Correct! Conductors must meet the 135% current requirement. Capacitor conductors must be sized to handle at least 135% of the capacitor’s current to ensure safety during operation. Wet locations require specific enclosure protection. 8 / 50 What must be ensured when installing a motor controller in a wet location (430.10(A))? a. Controllers cannot be installed in wet locations. b. The enclosure must be listed for wet locations. c. It must be installed 2 feet above the ground. d. No additional precautions are needed. Incorrect. Only enclosures listed for wet locations are allowed. Correct! Wet location enclosures must meet specific listing requirements. Motor controllers installed in wet locations must use enclosures listed for such conditions to prevent moisture ingress and ensure safety. These devices prevent specific electrical hazards in portable units. 9 / 50 What is the requirement for protection devices in cord-connected room air conditioners (440.65)? a. No protection devices are required. b. Leakage-current detector-interrupter (LCDI) or arc-fault circuit interrupter (AFCI). c. Ground-fault circuit interrupter (GFCI) only. d. No protection devices are required. Incorrect. These specific devices are required for room air conditioners. Correct! LCDI or AFCI devices are mandatory. Room air conditioners must include LCDI or AFCI devices to detect leakage currents or arc faults, providing enhanced safety. Grounding conductor sizing is tied to the overcurrent protection. 10 / 50 What is the required size of the equipment grounding conductor for motor circuits (430.122)? a. Based on the largest motor load only. b. Matching the branch circuit conductor size. c. No equipment grounding conductor is needed for small motors. d. Sized according to NEC Table 250.122 based on the overcurrent device. Incorrect. The grounding conductor size depends on the overcurrent device. Correct! Table 250.122 governs grounding conductor sizing. Equipment grounding conductors for motor circuits are sized based on the overcurrent device rating using NEC Table 250.122. Serviceability is a key requirement for disconnecting means. 11 / 50 How must disconnecting means for air-conditioning equipment be located (440.14)? a. At least 10 feet away from the equipment. b. Anywhere within the building. c. Within sight and readily accessible from the equipment. d. Inside a locked room for security. Incorrect. The disconnect must be within sight and readily accessible. Correct! NEC requires disconnects to be within sight and accessible. The disconnecting means must be within sight and readily accessible to ensure safe and quick access during maintenance or emergencies. Nameplates provide essential operational and safety information. 12 / 50 What must the nameplate of a hermetic refrigerant motor-compressor include (440.4(A))? a. Voltage only. b. Maximum circuit breaker size. c. Only the locked-rotor current. d. Manufacturer, voltage, frequency, and rated-load current. Incorrect. The nameplate includes more than just voltage or current. Correct! The nameplate provides critical specifications. The nameplate must include manufacturer details, voltage, frequency, and rated-load current to ensure proper installation and compliance. Locked-rotor codes relate to starting current. 13 / 50 What is the purpose of locked rotor indicating code letters on motor nameplates (430.7(B))? a. To specify torque characteristics. b. To provide service factor details. c. To indicate motor input with a locked rotor. d. To identify the motor’s voltage rating. Incorrect. The code letters indicate input with a locked rotor. Correct! They help identify motor input under locked-rotor conditions. Locked-rotor indicating code letters show the motor input in kilovolt-amperes per horsepower with a locked rotor, helping size protection devices. This article addresses motor-driven systems. 14 / 50 What is the scope of Article 440 (440.1)? a. Electric motor-driven air-conditioning and refrigerating equipment. b. Only motor-driven air compressors. c. All HVAC equipment including ductwork. d. Only single-phase air-conditioning systems. Incorrect. The scope includes air-conditioning and refrigerating systems specifically. Correct! The article focuses on motor-driven air-conditioning and refrigerating equipment. Article 440 applies to electric motor-driven air-conditioning and refrigerating equipment, including the circuits and controllers for such systems. The largest motor determines the starting point for sizing. 15 / 50 How should conductors for several motors and additional loads be sized (430.24)? a. Using the largest non-motor load ampacity. b. 125% of the largest motor’s full-load current plus all other full-load currents. c. Based on motor horsepower alone. d. By summing all full-load currents. Incorrect. Don’t forget to account for the largest motor’s current at 125%. Correct! This ensures conductors handle combined loads safely. Conductors must account for 125% of the largest motor’s full-load current and the sum of all other motor and load currents to ensure safe operation. Protection must account for the combined load of multiple motors. 16 / 50 How must motor branch circuits for two or more motors be protected (430.53)? a. Using a single overcurrent device protecting all motors and meeting NEC limits. b. With individual circuit breakers for each motor. c. By grounding the motors directly to the panelboard. d. With an overcurrent device rated at twice the largest motor's current. Incorrect. NEC allows a single device if properly sized. Correct! A single overcurrent device can protect multiple motors when sized appropriately. A single overcurrent device may protect all motors if it complies with NEC limits, considering the largest motor’s full-load current and contributions from others. High temperatures require measures to prevent accidental contact. 17 / 50 How must external surfaces of heating equipment be protected if operating above 60°C (140°F) (427.12)? a. No protection is needed for external surfaces. b. They must be guarded, isolated, or thermally insulated. c. Installed only in restricted areas. d. A warning label is sufficient. Incorrect. Surfaces must be guarded, isolated, or insulated for safety Correct! These measures are mandatory for high-temperature surfaces. Surfaces of heating equipment operating above 60°C (140°F) must be physically guarded, isolated, or thermally insulated to protect personnel from burns or injury. Suitability for the environment ensures durability and safety. 18 / 50 What is required for equipment installed in damp or wet locations (426.10)? a. It must be identified as suitable for the environment and installed according to manufacturer’s instructions. b. It must be enclosed in a metal box. c. No special requirements apply. d. It must be installed on a raised platform. Incorrect. NEC requires equipment to be listed for the specific environment. Correct! Suitability and manufacturer instructions are required. Equipment in damp or wet locations must be listed for such environments and installed per manufacturer guidelines to ensure safety and compliance. Overload protection ensures safety for motor operations. 19 / 50 How must the overload protection for motors on general-purpose branch circuits be configured (430.42)? a. According to 430.32 for individual motor overload protection. b. Not required for cord-and-plug-connected motors. c. Always integral to the motor. d. Provided only for motors over 10 HP. Incorrect. Overload protection follows specific NEC guidelines. Correct! 430.32 outlines the requirements for overload protection. Motors on general-purpose branch circuits require overload protection as specified in 430.32 to guard against overheating and failure to start. Markings must provide all critical operational data. 20 / 50 What marking is required for controllers used with hermetic refrigerant motor-compressors (440.5)? a. Only the motor-compressor model number. b. Current and temperature ratings only. c. Manufacturer’s name, voltage, full-load current, and locked-rotor current. d. Only voltage and frequency. Incorrect. The marking must include more comprehensive information. Correct! NEC requires these specific markings for controllers. Controllers must be marked with key details, including the manufacturer, voltage, fullload, and locked-rotor currents, to ensure suitability for the application. Outdoor installations require redundancy in grounding. 21 / 50 How must grounding conductors for outdoor air-conditioning equipment be installed (440.9)? a. Grounding is not required for outdoor installations. b. As wire-type conductors in metallic raceways. c. Using compression-type fittings only. d. Connected directly to the equipment’s frame. Incorrect. The NEC specifies the use of wire-type conductors in raceways for these systems. Correct! Wire-type grounding conductors are required in metallic raceways. Outdoor installations must include a wire-type grounding conductor within metallic raceways to ensure a reliable ground-fault return path. NEC specifies protective methods for nonheating leads. 22 / 50 How must nonheating leads for resistance elements be protected where they emerge from heating units (427.18(B))? a. By electrical tape. b. Using rigid metal conduit, intermediate metal conduit, or electrical metallic tubing. c. By direct burial in thermal insulation. d. Protection is optional for nonheating leads. Incorrect. NEC mandates specific protective conduits for these leads. Correct! Nonheating leads require proper conduit protection. Nonheating leads must be protected using rigid metal conduit, intermediate metal conduit, or electrical metallic tubing to ensure durability and safety. The protective device must accommodate the high inrush current during motor start. 23 / 50 What is the maximum branch-circuit short-circuit protection for individual motor-compressors (440.22(A))? a. 175% of the rated-load current. b. 125% of the full-load current. c. 100% of the nameplate current. d. 200% of the locked-rotor current. Incorrect. The correct maximum is 175% of the rated-load current. Correct! The NEC allows for 175% to handle starting current. The short-circuit protection device for motor-compressors may be rated up to 175% of the rated-load current to allow for starting currents while protecting against faults. Overload protection devices are selected by time rating. 24 / 50 What determines the time rating for overload protection devices (430.32(C)) a. The class of the overload relay. b. Manufacturer’s settings. c. Based on the type of motor. d. 100% of the motor’s nameplate rating. Incorrect. The overload relay class determines time rating Correct! Overload relay class determines trip time. The time rating of overload devices, such as Class 10, 20, or 30 relays, determines how long they delay tripping, allowing motors to start without nuisance trips. Manual controllers must ensure accessibility and safety. 25 / 50 What is the requirement for manually operated motor controllers (430.102(A))? a. Require a visible blade disconnect for operation. b. Can be installed remotely without visibility. c. Must always be installed next to the motor. d. Must be in sight of the motor and capable of being locked in the open position. Incorrect. Controllers must be in sight and lockable. Correct! Controllers must be visible and lockable. Manually operated motor controllers must be installed in sight of the motor and capable of being locked in the open position for safe operation and maintenance. Disconnecting means ensure safe servicing of heating systems. 26 / 50 What is required for disconnecting means in fixed pipeline or vessel heating systems (427.55(A))? a. A standard circuit breaker. b. Disconnecting means are optional. c. They must disconnect all ungrounded conductors simultaneously and be lockable in the open position. d. Only temperature control devices are needed. Incorrect. Disconnecting means must disconnect all ungrounded conductors and be lockable. Correct! These requirements ensure safe and compliant operation. The disconnecting means must simultaneously disconnect all ungrounded conductors and be capable of being locked in the open position to meet safety standards. Emergency stops are critical for motor safety. 27 / 50 What is required for motor emergency stops (430.91)? a. They must disconnect all phases simultaneously. b. They must override all start controls and stop the motor safely. c. Only one stop per motor is required. d. Emergency stops are optional for motors under 10 HP. Incorrect. Emergency stops must have overriding capabilities. Correct! Emergency stops ensure safe shutdown of motors. Emergency stops must override all start controls and safely shut down the motor to prevent damage or hazards. Cord lengths are limited to ensure safety and prevent damage. 28 / 50 What is the allowable cord length for a room air conditioner rated at 120 volts (440.64)? a. Any length if properly secured. b. 12 feet. c. 6 feet. d. 10 feet. Incorrect. The maximum allowable length for 120-volt units is 10 feet. Correct! The maximum cord length is 10 feet. The cord for a 120-volt room air conditioner must not exceed 10 feet to minimize risks of overheating and mechanical damage. Hazardous locations demand robust construction. 29 / 50 What is required for motor terminal housings in hazardous locations (430.12)? a. They must be rated for 600 volts or more. b. Any enclosure is sufficient. c. They must be metallic or listed for hazardous locations. d. Nonmetallic housings are always allowed. Incorrect. Only metallic or specially listed housings are allowed. Correct! Robust housing prevents risks in hazardous areas. Motor terminal housings in hazardous locations must be metallic or listed specifically for those conditions to prevent hazards. Clear identification ensures proper use and maintenance. 30 / 50 How must auxiliary devices in motor controllers be marked (430.8(B))? a. No marking is required for auxiliary devices. b. With a generic label indicating “accessory.” c. Only with their voltage rating. d. With their purpose and function if not apparent. Incorrect. Markings must clarify the device’s purpose and function. Correct! Clear identification is mandatory for auxiliary devices. Auxiliary devices in motor controllers must be marked with their purpose and function if the use is not readily apparent, ensuring clarity for maintenance and operation. Liquids can cause motor failure and safety risks. 31 / 50 What protection is required for motors subject to dripping liquids (430.11)? a. No special protection. b. A separate grounding conductor. c. Guards or enclosures to prevent liquid damage. d. Raised installation 3 feet above the ground. Incorrect. NEC requires guards or enclosures for protection. Correct! Protection from liquids is mandatory. Motors must have guards or enclosures to protect against damage from liquids,ensuring reliability and safety. The watt density ensures effective operation without overheating. 32 / 50 What is the maximum watt density for embedded deicing equipment (426.20(A))? a. 2000 watts/m² (185 watts/ft²). b. 800 watts/m² (75 watts/ft²). c. 1000 watts/m² (93 watts/ft²). d. 1300 watts/m² (120 watts/ft²). Incorrect. The maximum watt density is 1300 watts/m². Correct! 1300 watts/m² (120 watts/ft²) is the limit. The maximum watt density for embedded de-icing equipment is 1300 watts/m² (120 watts/ft²) to ensure safe and efficient operation. Markings provide essential data for proper application. 33 / 50 What marking is required for motor controllers (430.8)? a. Locked-rotor current rating. b. Voltage rating only. c. Manufacturer’s name, voltage, current or horsepower rating, and short-circuit current rating. d. Installation date and location. Incorrect. These markings are critical for safety and compliance. Correct! NEC mandates these markings on controllers. Motor controllers must be marked with key specifications such as voltage, current or horsepower, and short-circuit current rating to ensure correct application. Motor markings provide critical information for installation and operation. 34 / 50 What is required for motor marking (430.7(A))? a. Only the motor’s horsepower rating. b. Manufacturer, voltage, frequency, and full-load current. c. Only the manufacturer’s name. d. The locked-rotor current only. Incorrect. Motor markings must include more than just the manufacturer’s name. Correct! These details are mandatory for proper identification. Motors must be marked with details such as manufacturer, voltage, frequency, and fullload current to meet NEC requirements. Markings help size circuits and protective devices. 35 / 50 How must equipment supplying multimotor loads be marked (440.4(B))? a. Only voltage and current ratings. b. Minimum circuit ampacity and maximum short-circuit protection. c. Locked-rotor current of the largest motor. d. Phase and frequency only. Incorrect. The markings include circuit ampacity and protective ratings. Correct! These markings guide safe equipment installation. Multimotor equipment must be marked with minimum circuit ampacity and maximum short-circuit protection to ensure safe installation and operation. Proper grounding is essential for motor control circuits. 36 / 50 How must motor control circuits be grounded (430.72)? a. By connection to the motor's overload relay. b. They must include a separate equipment grounding conductor where required. c. Grounding is not required. d. Using the same grounding conductor as the motor. Incorrect. A separate grounding conductor may be required. Correct! Proper grounding ensures safety and compliance. Motor control circuits require a separate equipment grounding conductor if specified by the NEC, ensuring safety and fault clearing. NEC ensures conductors can be safely installed. 37 / 50 How must motor terminal enclosures be sized (430.12(C))? a. Based on motor horsepower alone. b. No specific sizing is required. c. Large enough to provide adequate bending space for conductors. d. Matching the size of the motor frame. Incorrect. Adequate bending space is mandatory for conductor safety. Correct! Bending space must be considered in enclosure sizing. Motor terminal enclosures must be adequately sized to provide sufficient bending space for conductors, ensuring proper installation and safety. NEC defines this type of equipment for specific load calculations. 38 / 50 How is fixed outdoor electric deicing and snow-melting equipment classified (426.4)? a. As an emergency load. b. As a continuous load. c. As an intermittent load. d. As a variable load. Incorrect. This equipment is classified as a continuous load for calculation purposes. Correct! It is classified as a continuous load. Fixed outdoor electric de-icing and snow-melting equipment is classified as a continuous load, requiring sizing of branch circuits and overcurrent protective devices at 125% of the load. Grounding ensures safety by preventing electrical faults. 39 / 50 What grounding requirement applies to fixed outdoor deicing and snowmelting equipment (426.27)? a. Grounding braid or sheath must be provided as part of the heated section. b. Only equipment above 150 volts must be grounded. c. No grounding is required. d. Grounding is only required for equipment installed in wet locations. Incorrect. Grounding braid or sheath is mandatory for this equipment. Correct! Grounding braid or sheath must be included. A grounding braid or sheath is required as part of the heated section of the cable, panel, or unit, ensuring safety in all installations. The NEC specifies precise wire-bending space for safety. 40 / 50 What defines the minimum wire-bending space for motor controller enclosures (430.10(B))? a. The size of the controller. b. Table 430.10(B) based on wire size and configuration. c. Manufacturer’s recommendations. d. No defined standard exists. Incorrect. The table defines wire-bending space based on wire size. Correct! Table 430.10(B) establishes the requirements. Table 430.10(B) provides the minimum bending space required to safely route wires in motor controller enclosures. The conductor size must account for continuous operation. 41 / 50 What is the ampacity requirement for single motor branch-circuit conductors (430.22)? a. 125% of the full-load current. b. 100% of the full-load current. c. 150% of the full-load current. d. Based on the motor’s service factor. Incorrect. The correct value is 125% of the full-load current. Correct! 125% ampacity ensures safe operation. Single motor branch-circuit conductors must have an ampacity of at least 125% of the motor’s full-load current rating to handle sustained operation. Motors require high inrush current at startup. 42 / 50 What is the purpose of time-delay fuses for motor circuits (430.52(C) (1))? a. To provide faster fault clearing. b. To eliminate the need for overload relays. c. To allow high starting currents without tripping. d. To protect against sustained overloads. Incorrect. Time-delay fuses manage high inrush currents effectively. Correct! Time-delay fuses handle startup currents safely. Time-delay fuses permit high starting currents while still providing protection against sustained short circuits and ground faults. Article 430 has a broad scope for motor-related systems. 43 / 50 What does NEC Article 430 primarily cover (430.1)? a. Motors, motor circuits, and motor controllers. b. Generators and motors. c. Motor installation only. d. All electrical machines. Incorrect. Article 430 covers more than just motor installation. Correct! It includes motors, circuits, and controllers. NEC Article 430 addresses motors, branch-circuit conductors, feeders, overload protection, and motor controllers. Tap conductors must be protected and sized appropriately. 44 / 50 What ampacity must motor feeder tap conductors have when limited to 10 feet in length (430.28(1))? a. 1/3 of the feeder conductor ampacity. b. No ampacity requirement if enclosed. c. Same ampacity as the feeder conductors. d. No less than the feeder conductors and protected by an overcurrent device. Incorrect. Tap conductors must be protected and properly sized. Correct! Protection and matching ampacity are required Feeder tap conductors up to 10 feet must have an ampacity matching the feeder and terminate in a protective device to prevent overloading. Overload protection considers the motor’s service factor. 45 / 50 How must overload devices for continuous-duty motors be rated (430.32)? a. 115% for all motors. b. 100% of the motor’s nameplate current. c. 125% for motors with a service factor of 1.15 or greater. d. At 150% of full-load current. Incorrect. Overload device settings depend on service factor and temperature rise. Correct! These settings ensure proper protection. Overload devices must trip at 125% of the motor’s full-load current for motors with a service factor of 1.15 or greater or a temperature rise of 40°C or less. Identification ensures visibility and safety throughout the pipeline or vessel. 46 / 50 What is required for identification of electrically heated pipelines and vessels (427.13)? a. Marked at the start and end points only. b. Only marked near service equipment. c. Caution signs or markings at intervals not exceeding 6 meters (20 feet). d. Identification is optional. Incorrect. Markings are required at specified intervals for safety and compliance. Correct! Markings must be placed every 6 meters (20 feet). Electrically heated pipelines and vessels must be marked with caution signs or similar markings at intervals not exceeding 6 meters (20 feet) for clear identification. The largest motor determines the starting point for feeder sizing. 47 / 50 What is the required ampacity for motor feeder conductors supplying several motors (430.25)? a. No additional ampacity requirement for feeders. b. 100% of the total load. c. Twice the ampacity of the smallest motor load. d. 125% of the largest motor’s full-load current plus the sum of other motor loads. Incorrect. The largest motor’s current must be factored at 125%. Correct! This calculation ensures adequate feeder capacity. Feeder conductors must account for 125% of the largest motor’s full-load current and the total of all other connected loads to ensure capacity. Torque motors are rated differently than standard motors. 48 / 50 How must torque motors be rated for ampacity (430.6(B))? a. No specific rating is required. b. Based on full-load current. c. Based on horsepower. d. Using locked-rotor current. Incorrect. Locked-rotor current determines the rating. Correct! Locked-rotor current is the basis for rating. Torque motors are rated using locked-rotor current, as they often operate at standstill, necessitating proper conductor and device sizing. Hazardous locations require specific markings for reconditioned equipment. 49 / 50 What must reconditioned motors used in hazardous locations be identified as (430.2)? a. Listed as reconditioned for hazardous locations. b. Original equipment. c. No identification is necessary. d. Marked with the manufacturer’s name only. Incorrect. Reconditioned motors must be listed for hazardous locations. Correct! Listing ensures proper identification and safety. Reconditioned motors for hazardous areas must be listed as reconditioned to ensure compliance and safety. NEC specifies reduced starting current for wye-start configurations. 50 / 50 What is the maximum rating for short-circuit protection for wye-start, delta-run motors (430.52)? a. 72% of the motor’s full-load current. b. 125% of the branch-circuit ampacity. c. 100% of the motor’s full-load current. d. Determined by the controller. Incorrect. 72% is the correct value for these motors. Correct! The rating accounts for reduced starting current. The conductors and protection devices for wye-start, delta-run motors are sized at 72% of the full-load current to account for reduced starting current. Your score is LinkedIn Facebook Twitter 0% Restart quiz Exit Rate & Review Thank you for taking the time to leave us a review! Your feedback is greatly appreciated and helps us improve our services. Send feedback Leave a Reply Cancel replyYour email address will not be published. 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