According to NEC Article 424.24, electric space-heating cables are permitted to extend beyond the room or area in which they originate. This provision allows for greater flexibility in the installation of heating systems in various spaces.

According to NEC Article 426.28, all equipment rated 250V or less and 60A or less, whether single-phase or three-phase, including tire inflation machines provided for public use and vending machines, must be equipped with GFCI (Ground Fault Circuit Interrupter) protection for personnel. This requirement is essential to reduce the risk of electric shock in public settings.

According to NEC Article 410.66, an electric-discharge or LED luminaire or listed assembly can be cord connected if the luminaire is located directly below the outlet. Additionally, the cord must be visible for its entire length except at terminations and must not be subject to strain or physical damage. These conditions help ensure safe and effective installation of cord-connected luminaires.

According to NEC Article 422.16, receptacles for built-in dishwashers and trash compactors must be located in a way that protects against physical damage to the flexible cord. This is crucial for ensuring the safety and longevity of the appliance’s electrical connection.

According to NEC Article 406.12, nonlocking-type 125V and 250V, 15A and 20A receptacles installed in guest rooms and guest suites of hotels and motels, child care facilities, preschools, and elementary education facilities must be listed as tamper-resistant. This requirement is in place to enhance safety, particularly in environments where children or guests may be present.

According to NEC Article 424.24, electric space-heating cables are prohibited from being installed in tub and shower walls and under cabinets or similar built-ins having no clearance to the floor. Therefore, the correct answer is a and b, as both locations are restricted for safety reasons.

According to NEC Article 422.34, for permanently connected appliances rated at not over 300 VA or 1/8 hp, the branch-circuit overcurrent device may serve as the disconnecting means, provided that the switch or circuit breaker is within sight from the appliance or is lockable as specified in 110.25. This requirement ensures both safety and accessibility for disconnecting the appliance.

According to NEC Article 426.28, all equipment rated 250V or less and 60A or less, whether single-phase or three-phase, such as automotive vacuum machines for public use, drinking water coolers, and cord-and-plug-connected high-pressure spray washing machines, must be provided with GFCI (Ground Fault Circuit Interrupter) protection for personnel. This requirement enhances safety in environments where electrical equipment is used near water or in public settings.

According to NEC Article 424.24, the minimum clearance required between the heating elements of electric space-heating cables installed in ceilings and outlet boxes or junction boxes used for mounting surface luminaires must be at least 8 inches. This clearance is essential to prevent potential overheating and ensure safe operation.

According to NEC Article 422.16, an in-sink waste disposer can be cord-and-plug-connected, but the receptacles must be properly located, shielded, or guarded to protect against physical damage to the flexible cord. This ensures the safety and longevity of the connection while minimizing the risk of electrical hazards.

According to NEC Article 406.5(E), receptacles that are installed in or on countertop surfaces or work surfaces must not be placed in a face-up position unless they are specifically listed for countertop or work surface applications. This requirement is in place to enhance safety and minimize the risk of electrical shock or damage to devices.

According to NEC Article 411, lighting systems and their associated components are permitted to operate at no more than 15V AC or 30V DC in locations where wet contact is likely to occur. These limits are established to enhance safety and reduce the risk of electric shock in wet environments.

According to NEC Article 422.16, the length of the cord for a trash compactor must not exceed 4 feet, measured from the face of the attachment plug to the plane of the rear of the appliance. This limitation helps ensure safety and reduces the risk of cord damage during operation.

According to NEC Article 480.6, when mating dissimilar metals, antioxidant material suitable for the battery connection shall be used where it is recommended by the battery manufacturer. This practice helps prevent corrosion and ensures a reliable electrical connection.

According to NEC Article 422.16, the length of the cord for a built-in dishwasher must not exceed 6.50 feet, measured from the face of the attachment plug to the plane of the rear of the appliance. This limitation helps maintain safety standards and prevents potential hazards related to cord damage.

According to NEC Article 410.16, any combustible ceiling finish that is exposed between the edge of a ceiling-suspended (paddle) fan canopy or pan and an outlet box, with a surface area of 180 sq in. or more, must be covered with noncombustible material. This requirement is intended to enhance safety by preventing potential fire hazards.

A drop box is a box containing pendant- or flush-mounted receptacles attached to a multiconductor cable using strain relief or a multipole connector. This configuration is commonly used in temporary installations or environments where mobility is required.

According to NEC Article 422.33(A), for cord-and-plug-connected household electric ranges, an attachment plug and receptacle connection at the rear base of the range can serve as the disconnecting means if it is accessible from the front by the removal of a drawer. This accessibility is crucial for ensuring safe operation and maintenance of the appliance.

According to NEC Article 411, lighting systems and their associated components are permitted to operate at no more than 30V AC or 60V DC. This ensures that the systems remain safe for use while providing adequate lighting solutions.

According to NEC Article 404.9(B), snap switches are considered part of an effective ground-fault current path when:

1. The switch is mounted with metal screws to a metal box or cover that is connected to an approved equipment grounding conductor (Option B).
2. An equipment grounding conductor or bonding jumper is connected to the grounding terminal of the metal mounting yoke (Option C).

Both methods ensure proper grounding for fault-current safety.

According to NEC Article 430.6(A)(1), the conductor ampacity for AC adjustable voltage motors must be calculated based on the maximum operating current listed on either the motor or its nameplate. This ensures accurate sizing of conductors to prevent overheating and ensure safety.

According to NEC Article 424.24, electric space-heating cables are permitted to extend beyond the room or area in which they originate. This allows for flexibility in installation while ensuring that the heating system functions effectively.

According to NEC Article 422.5, GFCI protection for 15 kW or smaller portable generators is not required if the 125V receptacle outlet(s) is interlocked so that it cannot be used when any 125/250V receptacle(s) is in use. This design ensures safety by preventing simultaneous use that could lead to potential hazards.

According to NEC Article 400.8, luminaires that need to be adjusted or aimed after installation may be cord connected without an attachment plug, as long as the exposed cord is suitable for hard usage or extra-hard usage and is kept to the length necessary for the required adjustment. This provision ensures both flexibility in installation and safety in electrical usage.

According to NEC Article 430.109(A)(1), motor circuit switches must be horsepower rated for motor control applications. This ensures that the switch can handle the load associated with the motor’s horsepower rating. General-use and isolating switches are not necessarily rated for motor loads, and overcurrent devices are meant for protection, not for switching motor circuits.

NEC Article 424.19 requires that when heating equipment is supplied by more than one source, feeder, or branch circuit, the disconnecting means must be grouped and identified to clearly indicate the presence of multiple disconnecting means. This is essential for safety and compliance.

NEC Article 480.9(A) states that a disconnecting means must be provided for all ungrounded conductors in a stationary battery system with a voltage exceeding 60 volts DC. This ensures the ability to isolate and de-energize the system safely during maintenance or emergencies.

According to NEC Article 406.9, a flush device cover plate that includes a night light or Class 2 output connector(s) must be listed and constructed so that the night light and/or Class 2 circuitry is integral with the cover plate. This requirement ensures that the device meets safety standards and functions properly within electrical systems.

According to NEC Article 406.12, in dwelling units, all nonlocking-type 125V and 250V, 15A and 20A receptacles installed in business offices, corridors, waiting rooms, clinics, medical and dental offices, outpatient facilities, as well as assembly occupancies like gymnasiums and dormitories, must be listed as tamper-resistant. This ensures safety in areas where children or the public may be present.

According to NEC Article 408.4, all switchboards, switchgear, and panelboards supplied by a feeder(s) in locations other than one- or two-family dwellings must be permanently marked to indicate each device or equipment where the power supply originates. This marking is crucial for safety and proper identification of power sources.

According to NEC Article 422.5, if the 15 kW or smaller portable generator was manufactured or remanufactured prior to January 1, 2015, then listed cord sets or devices incorporating listed GFCI protection for personnel identified for portable use shall be permitted. This regulation helps ensure the safety of users with older generator models.

According to NEC Article 422.16, the receptacle for a built-in dishwasher must be located adjacent to the space occupied by the dishwasher. This ensures that the dishwasher is easily accessible for connection and maintenance while adhering to safety standards.

According to NEC Article 430.52(C)(1) and Table 430.52, a dual-element (time-delay) fuse used to protect a single-phase motor must not exceed 175% of the motor’s rated full-load current. This allows for adequate motor starting current while providing protection against sustained overcurrents.

Step 1: Calculate Primary Full-Load Current

Primary Full-Load Current (I)=kVA×1000Voltage×3\text{Primary Full-Load Current (I)} = \frac{\text{kVA} \times 1000}{\text{Voltage} \times \sqrt{3}}Primary Full-Load Current (I)=Voltage×3

NEC Article 455.7(A) allows the overcurrent protection for phase converters to be set at up to 125% of the nameplate input current for variable loads:

$$100\text{FLA}\times 1.25=125\text{A}.$$

According to NEC Article 422.16, the receptacle for a trash compactor must be located either in the space occupied by the appliance or adjacent to the space. This requirement ensures that the trash compactor is easily accessible for operation and maintenance while maintaining safety.

According to NEC Article 424.24, electric space-heating cables shall not be installed over cabinets if the clearance from the ceiling is less than the minimum horizontal dimension of the cabinet to the nearest cabinet edge that is open to the room or area. This requirement is in place to ensure safety and prevent potential fire hazards.

According to NEC Article 408.4(B), the label required for switchboards, switchgear, and panelboards must be permanently affixed and of sufficient durability to withstand the environment involved; however, it is not required to be handwritten. This ensures that the labels remain clear and legible over time, contributing to safety and proper identification of the equipment.

According to NEC Article 422.5, bonded 15 kW or smaller portable generators must have GFCI protection on all 125V receptacle outlets rated at 15A and 20A. This requirement is essential for ensuring personnel safety and preventing electrical shock hazards.

According to NEC Article 424.24, electric space-heating cables shall not be installed through or under walls. Therefore, they must be installed in a manner that complies with the safety standards outlined in the NEC, making the correct answer “a or b.”

According to NEC Article 422.33, for cord-and-plug- (or attachment fitting-) connected appliances, an accessible plug (or attachment fitting) and receptacle combination can serve as the disconnecting means. This ensures that the disconnecting means is easily reachable for safe operation and maintenance.

According to NEC Article 422.16, range hoods may be cord-and-plug-connected using a flexible cord identified as suitable for range hoods in the manufacturer’s installation instructions, provided either that the length of the cord is not less than 18 inches and not over 4 feet, or that receptacles are located to protect against physical damage to the flexible cord. This ensures safety and compliance during installation.

According to NEC Article 406.5, receptacle assemblies that are listed for work surface or countertop applications can be installed in work surfaces. This includes GFCI (Ground Fault Circuit Interrupter) receptacle assemblies, which are essential for protecting against electrical shock in wet or damp locations, such as kitchens or bathrooms.

Per NEC Article 430.72(B), control circuit conductors extending beyond enclosures are allowed a maximum overcurrent protection device size of 300% of the conductor’s ampacity. For #14 AWG conductors:

1. Ampacity (from NEC Table 310.16): 15A.
2. Maximum overcurrent protection: $15A\times 3=45A$.

Therefore, the correct maximum overcurrent protection device size for #14 AWG conductors in this application is 45A.

According to NEC Article 422.5, unbonded 15 kW or smaller portable generators that have both 125V and 125/250V receptacle outlets must have listed GFCI protection for personnel that is integral to the generator or receptacle on all 125V, 15A and 20A receptacle outlets. This ensures that the generators provide adequate protection against electrical shock.

According to NEC Article 480.4, storage batteries, other than lead-acid batteries, and battery management equipment must be listed. This means that they have been tested and certified by a recognized testing laboratory to meet specific safety and performance standards.

According to NEC Article 430.102, for permanently connected motor-operated appliances with motors rated over 1/4 HP, a switch or circuit breaker located within sight from the motor-operated appliance, or capable of being locked in the open position in compliance with 110.25, may serve as the appliance disconnect. Additionally, appliances rated over 15A also fall under this requirement, making options b and c correct.

According to NEC Article 422.5, receptacle outlets that are part of a 15 kW or smaller portable generator must have listed ground-fault circuit-interrupter (GFCI) protection for personnel that is integral to the generator or receptacle. This requirement is essential to enhance safety and prevent electrical shock when using portable generators.

According to NEC Article 424.24, electric space-heating cables are not permitted to be installed in closets (except as noted in 424.38(C)), over the top of walls where the wall intersects the ceiling, or over partitions that extend to the ceiling unless they are isolated single runs of embedded cable. Therefore, the correct answer is that they shall not be installed in any of these specified locations.

NEC Article 450.14 requires that a transformer disconnecting means be lockable in the open position to ensure safety and prevent accidental energization during maintenance.