Washington 06(Limited Energy) Nec & Theory

Fire alarm cables that are not terminated at equipment and not identified for future use are considered "abandoned" because they are not being used or maintained and are left unused or neglected.

The statement is true because exposed network-powered broadband cables must be secured to structural components using appropriate fittings such as straps, staples, hangers, or similar devices. These fittings should be designed and installed in a way that does not cause any damage to the cables. This ensures the safety and proper functioning of the cables while also preventing any potential hazards or accidents.

The correct answer is "Fire-stopped." Openings around penetrations of communications cables and raceways through fire-resistant-rated walls, partitions, floors, or ceilings need to be fire-stopped using approved methods to maintain the fire-resistance rating. This means that appropriate materials and techniques must be used to prevent the spread of fire through these openings, ensuring that the fire-resistance rating of the structure is maintained.

The correct answer is solid or stranded copper. This is because NPLFA circuits require a conductor material that has good conductivity and low resistance. Copper is widely used in electrical wiring due to its high conductivity, durability, and resistance to corrosion. Both solid and stranded copper conductors are suitable for NPLFA circuits, depending on the specific application and installation requirements.

If Class 2, Class 3, and PLTC cables are not terminated at equipment and not identified for future use with a tag, they are considered abandoned. This means that they are no longer in use or needed. Therefore, the statement "Class 2, Class 3, and PLTC cable not terminated at equipment and not identified for future use with a tag is considered abandoned" is true.

Underground communications wires and cables must be separated from electric light, power, Class 1, or NPLFA circuit conductors by a section made of brick, tile, concrete, or any of the above materials. This is to ensure the safety and integrity of the communication lines and to prevent interference or damage from the electrical conductors.

The hardware used to secure exposed CATV cables, such as straps, staples, cable ties, hangers, or similar fittings, are designed and installed in order to prevent any damage to the cables. This ensures that the cables remain intact and functional, without any physical harm or impairment.

According to Ohm's law, the formula to calculate voltage (E) is E = I * R. In this case, the given values are I = 6 amps and R = 2 Ohms. Plugging these values into the formula, E = 6 * 2 = 12 volts. Therefore, the correct answer is 12.

The correct answer is "Environment involved." Fire Alarm cables identified for future use need to be marked with a tag that can withstand the specific environment in which they will be installed. This ensures that the cables remain durable and functional, even in harsh conditions. Moisture and humidity are factors that can affect the cables' performance, but the overall environment involved encompasses all possible factors that may impact the cables. Therefore, marking the cables with a tag that can withstand the environment involved is the most appropriate choice.

The correct answer is OFCR. OFCR stands for Optical Fiber Cable Riser. In this scenario, since the cable is going to be used to run between multiple floors, it needs to be a riser cable. Riser cables are specifically designed for vertical applications and are suitable for installation in vertical shafts or runs between floors. OFC, OFCG, and OFCP are not the appropriate types of cables for this purpose.

The correct answer is OFNR AND OFCR. OFNR stands for Optical Fiber Nonconductive Riser and OFCR stands for Optical Fiber Conductive Riser. These types of cables are suitable for vertical runs in a shaft or from floor to floor. OFNR cables are designed to prevent the spread of fire and are suitable for riser applications, while OFCR cables have additional conductive properties to provide grounding and are used in riser applications where grounding is required.

The correct answer is OFNP and OFCP. Optical fiber plenum cables that are listed as suitable for use in space used for environmental air include these two types. OFNP stands for Optical Fiber Nonconductive Plenum, which is designed for use in plenum spaces, such as the area above drop ceilings or below raised floors, where air circulation is necessary for heating, ventilation, and air conditioning systems. OFCP stands for Optical Fiber Conductive Plenum, which is similar to OFNP but includes additional conductive properties to meet specific safety requirements.

Network-powered broadband communications cables should not be attached to a cross-arm that carries electric lights or power conductors. This is because the electromagnetic interference generated by the power conductors and the electrical lights can interfere with the signal transmission in the network-powered broadband communications cables. Therefore, it is recommended to keep these cables separate from any sources of electrical power to ensure optimal performance and minimize interference.

Communications wires and coaxial cables must have a vertical clearance of at least 8 feet from all points of roofs above which they pass. This clearance is necessary to ensure that the wires and cables do not come into contact with the roof or any other objects, which could cause damage or interference with the communication signals. It also allows for proper installation and maintenance of the wires and cables.

The branch circuit supplying the fire alarm equipment should not have any other loads connected to it. This is because the fire alarm equipment requires a dedicated circuit to ensure that it operates efficiently and does not get overloaded. Connecting other loads to the circuit can lead to power fluctuations and potential malfunctions in the fire alarm system, jeopardizing its effectiveness in detecting and alerting about fires. Therefore, it is crucial to have no other loads connected to the branch circuit supplying the fire alarm equipment.

Coaxial cables are used for transmitting high-frequency signals, such as those used in television and internet connections. To ensure proper functioning and to prevent interference, these cables need to have a sufficient vertical clearance from all points of roofs above which they pass. The correct answer of 8 feet ensures that there is enough distance between the cables and the roof to avoid any potential signal degradation or damage to the cables.

The accessible portion of abandoned coaxial cable should be removed. This is because abandoned cables can pose safety hazards and can interfere with the performance of active cables. Removing them ensures a clean and organized cable infrastructure, reducing the risk of accidents and improving overall network efficiency.

PLFA circuits, which stands for Power-Limited Fire Alarm, are used for fire alarm systems. These circuits can be installed in hoist ways using various types of conduits, including rigid metal conduit, rigid nonmetallic conduit, or electrical metal tubing. Therefore, any of the above options can be used for installing PLFA circuits in hoist ways.

Communication cables that are suitable for use in a vertical run in a shaft or from floor to floor, and that also have fire-resistant characteristics capable of preventing the carrying of fire from floor to floor, are referred to as riser cables.

Communications conductors and cables should be separated by at least 2 inches from conductors of power circuits, lighting circuits, or Class 1 circuits. This is to prevent interference and ensure the safety of the communication system.

A fused primary protector is a device that is connected between each line conductor and ground, and it includes both an arrestor and a fuse in series with each line conductor. This arrangement provides protection by both diverting excessive voltage to ground through the arrestor and by breaking the circuit in case of a fault or overload through the fuse. This ensures that the equipment connected to the line is protected from power surges and other electrical faults.

The insulation on NPLFA conductors should be rated for 600 Volts. This rating ensures that the insulation can withstand the voltage level without breaking down or causing any electrical hazards. Using insulation with a lower voltage rating may result in insulation failure and potential electrical accidents. Therefore, it is important to use insulation that is specifically rated for the voltage level at which it will be used.

When coaxial cable is placed in a raceway, compartment, outlet box, or junction box with the conductors of light or power circuits, or Class 1 circuits, it must be separated by a permanent barrier. This is to ensure that there is no interference or cross-talk between the coaxial cable and the other circuits. The permanent barrier acts as a physical separation, preventing any contact or interaction between the different circuits.

Cable used in a wet location for a NPLFA circuit shall be listed for use as such or have a moisture impervious metal sheath. This is because a wet location requires extra protection against moisture, and a moisture impervious metal sheath provides the necessary barrier to prevent water from entering the cable and causing damage. Insulating wrap, isolating sheath, and water-proof electrical tape coating may provide some level of protection, but they may not be as effective or durable as a moisture impervious metal sheath.

The correct answer is 18 AWG because smaller conductors may not be able to handle the current flow required for a PLFA circuit. AWG stands for American Wire Gauge, and it is a standardized system for measuring the diameter of electrical conductors. A larger AWG number indicates a smaller conductor size. Therefore, a smaller AWG number, such as 12 or 16, would have a larger conductor size and be able to handle more current flow. However, a smaller conductor, such as 22 AWG, would have a smaller size and may not be able to safely carry the necessary current for a PLFA circuit.

The metallic sheath of communications cable entering buildings can be grounded at the point of emergence through an exterior wall, grounded at the point of emergence through a concrete floor slab, or interrupted as close to the point of entrance as practicable by an insulating joint. This means that any of these options are acceptable for grounding the metallic sheath of the cable.

Communications wires and cables need to be separated by at least 4 inches from electric light or power conductors that are not in a raceway or cable. This is necessary to prevent interference and ensure the safety of the communication system.

AC and DC circuits, rated at 600 volts or less, are required to be permitted to occupy the same equipment wiring enclosure, cable, or raceway. This means that it is mandatory for both types of circuits to coexist in the same space.

Coaxial cables used for community antenna television (CATV) systems, when installed in vertical runs and penetrating multiple floors or in a shaft, should be of type CATVR. This specific type of coaxial cable is designed to meet the requirements for vertical installations, ensuring optimal performance and signal transmission in these scenarios. CATVR cables are specifically engineered to withstand the challenges of vertical runs, providing reliable and efficient connectivity for CATV systems.

For non-power limited fire alarm circuits, an 18 AWG conductor is considered protected if the over-current device protecting the circuit is not over 7A. This means that as long as the over-current device does not exceed 7A, the 18 AWG conductor will be safe and not at risk of being damaged due to excessive current flow.

Article 725 of the NEC specifically governs the installation of Class 1, Class 2, and Class 3 remote-control, signaling, and power-limited circuits. It provides rules to prevent fire and electric shock in limited energy systems. Articles 210, 300, and 800 deal with other aspects of electrical installations, such as branch circuits, wiring methods, and communications systems, respectively, making Article 725 the correct and relevant choice for limited energy systems.

General use communications cables will be marked as CM and CMG. CM stands for "Communications Multipurpose" and is the most common rating for general use cables. CMG stands for "Communications Multipurpose General" and is a higher rating that indicates the cable has met additional fire safety requirements. Therefore, both CM and CMG markings can be found on general use communications cables.

The correct answer is "Extension cord listing requirements". This means that a flexible cord used in listed extension cord sets will be considered protected when it meets the requirements and standards set forth for extension cords. This ensures that the cord has been tested and approved for safe use in branch-circuit overcurrent protection.

The term "readily accessible" refers to equipment that can be approached easily without barriers like locked doors or elevation changes. This definition emphasizes safety and compliance, ensuring that individuals can access equipment as needed without undue obstacles. Such accessibility is crucial for maintenance, operation, or emergency situations, highlighting the importance of having equipment available for users without complicated entry requirements.

All mechanical elements used to terminate a grounding electrode conductor or bonding jumper to a grounding electrode should be accessible. This means that they should be easily reachable and not obstructed, allowing for proper maintenance, inspection, and repairs if necessary. By ensuring accessibility, it ensures that the grounding system is functioning effectively and can be easily accessed when needed.

Conductors of Class 2 and Class 3 circuits shall not be placed in any enclosure, raceway, cable, or similar fittings with conductors of Class 1 or electric light or power conductors, except when they are separated by a barrier. This is because Class 2 and Class 3 circuits have different voltage requirements and safety regulations compared to Class 1 and power conductors. Placing them together without a barrier could lead to potential hazards such as electrical interference or short circuits. Therefore, they need to be separated by a barrier to ensure the safety and proper functioning of the circuits.

The correct answer is "Circuit Integrity". NPLFA cable listed with the suffix "CI" indicates that it is designed to maintain its circuit integrity even in the event of fire or extreme temperatures. This type of cable is commonly used in critical applications where fire resistance and the ability to maintain communication during emergencies are essential.

When underground service conductors are buried 18 inches or more below grade, it is important to identify their location to prevent accidental damage. One way to do this is by using a warning ribbon in the trench. This ribbon serves as a visual indication of the presence of the conductors and alerts anyone who may be digging or working in the area to exercise caution. It helps prevent accidental digging or damage to the conductors, ensuring the safety and integrity of the electrical system.

Communication plenum cable shall be listed as being suitable for use in other spaces used for environmental air. "Listed" means that the cable has been tested and meets the specific requirements and standards set by regulatory authorities. This ensures that the cable is safe to use in spaces where air circulation is important, such as plenum spaces. The listing indicates that the cable has undergone rigorous testing and has been approved for use in these specific environments.

Conductive optical fiber cables can contain non-current carrying conductive members such as metallic strength members, vapor barriers, or armor/sheath. These components are included in the design of the cable to provide additional strength, protection against moisture or other environmental factors, and to ensure the overall integrity of the cable. Therefore, any of these options could be present in conductive optical fiber cables.

When installing a cable or raceway-type wiring method through bored holes in both exposed and concealed locations, the edge of the hole must be at least 1-1/4 inch away from the nearest edge of the wood member. This requirement ensures that there is enough space for the wiring method to be properly installed and protected, reducing the risk of damage or overheating.

In air-handling plenum spaces, the NEC requires that low-voltage cables be rated for plenum use, such as CL2P or CL3P. These ratings ensure that the cables are designed to limit the spread of fire and produce minimal smoke, which is crucial in plenum spaces where air circulation can spread hazardous fumes. Cables without these ratings are not permitted in plenum spaces, and while metal conduit can offer protection, it’s not the requirement here.

The correct answer is "a or b". Type OFNG, OFN, OFCG, and OFC optical fiber cables may be used as risers when they are either encased in a metal raceway or located in a fireproof shaft having a firestop at each floor. This ensures the safety and protection of the cables in case of a fire, as both options provide a level of fire resistance.

BMU is the correct answer because when installing a medium-powered broadband network for an outdoor, underground run, a cable type that is specifically designed for outdoor and underground use is required. BMU is a cable type that meets these requirements and is suitable for such installations. BLX, BLU, and Cat5E are not specifically designed for outdoor and underground use, making BMU the most appropriate choice.

A bonding jumper not smaller than 6 AWG copper or equivalent should be connected between the communications grounding electrode and power grounding electrode system at the building or structure served when separate electrodes are used. This ensures a proper electrical connection between the two grounding systems, allowing for the safe dissipation of electrical currents and preventing potential electrical hazards.

Audio system circuits using Class 2 or Class 3 wiring methods shall not be permitted to be installed in the same cable or raceway with power-limited fire alarm conductors or cable. This is because power-limited fire alarm conductors or cable require a separate cable or raceway to ensure proper functioning and to prevent interference or damage to the fire alarm system. Mixing these circuits together could compromise the safety and effectiveness of the fire alarm system.

Communications wires and cables need to have a temperature rating that is not less than 60 degrees Celsius. This temperature rating ensures that the wires and cables can withstand high temperatures without getting damaged or causing any safety hazards. It is important for communication systems to have cables and wires that can handle high temperatures to ensure reliable and efficient communication. A temperature rating of 60 degrees Celsius is necessary to meet these requirements.

The given options include standard sizes for fuses and inverse time circuit breakers, except for the 75A option. This indicates that 75A is not a standard size for either a fuse or an inverse time circuit breaker.

When encountering rock bottom while driving a ground rod at an angle up to 45 degrees, burying the electrode in a trench that is at least 30 inches deep is the correct solution. This depth allows for proper grounding and ensures that the electrode is securely placed in the ground, even in rocky conditions.

Wiring laid in notches of wood studs, joists, rafters, or other wood members must be protected by a steel plate at least 1/16 inch thick. This thickness is necessary to provide adequate protection to the wiring from potential damage caused by nails, screws, or other fasteners that may be driven into the wood members. The steel plate acts as a barrier, preventing any potential puncture or penetration of the wiring, ensuring its safety and integrity.