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Since the construction of the world’s first smart building in the United States in 1984, there has been no unified definition for smart buildings. The International Society for Intelligent Engineering believes that a smart building should be designed to provide the necessary functions and offer flexibility to adapt to changes in users’ requirements regarding the building’s uses and information technology needs. In other words, a smart building must be safe, comfortable, well-structured, integrated, efficient in terms of investment utilization, energy-saving, and equipped with strong functional capabilities to meet users’ needs for high efficiency. Therefore, its basic requirements are: complete control, management, maintenance, and communication facilities to facilitate environmental control, security management, monitoring, and alarm functions, as well as to provide building users with a comfortable, pleasant, and convenient environment and atmosphere that helps improve work efficiency and stimulate creativity. Generally, modern smart buildings are primarily composed of three systems: the Building Automation System (BAS), the Office Automation System (OAS), and the Information and Communication System (CAS). Computer network technology and communication technologies are used to integrate these three systems together. The intelligent building management system integrates the wiring systems for various signals such as voice, data, video, and surveillance through unified planning and design, to create a standard wiring system. This serves as a comprehensive cabling system (GCS) for data transmission within a building; it is also known as the low-voltage system, and can be divided into comprehensive cabling within a single building and comprehensive cabling between buildings in a complex. Technical foundations for the development of intelligent buildings: contemporary building technologies, modern computer technology, modern control technology, and modern communication technology. From the above aspects related to the components of smart buildings, it can be seen that they are characterized by a high density of cables, numerous system devices, complex microelectronic equipment, and weak overvoltage protection capabilities. To ensure the safe and normal operation of these systems and devices, special measures must be taken for protection, and lightning protection, grounding, and interference resistance are among the important, essential, and effective protective measures. Lightning protection for low-voltage systems: In terms of lightning protection for low-voltage systems, aside from direct lightning strikes, the most destructive factor is the secondary effects. Due to lightning’s characteristics of high voltage, large impulse currents, and instantaneity, strong lightning generates electrostatic fields, alternating electromagnetic fields, and electromagnetic radiation. Lightning waves can invade a system, as well as ground potential surges, resulting in Lightning Electromagnetic Pulses (LEMPs). These pulses create strong changing electromagnetic fields that induce electric potentials and current in nearby metals ； On the one hand, it severely disrupts wireless and wired communications; on the other hand, by intruding into the signal inputs of microelectronic devices, it causes these devices to fail or burn out, thereby bringing networks down and ruining business operations. The International Society for Intelligent Engineering states that lightning is the natural enemy of high technology. Electronic devices have weak protection capabilities; the energy released by lightning strikes can reach hundreds of megajoules, and the difference in energy levels is quite significant, so measures must be taken to provide protection. The lightning protection for low-voltage systems, as part of the overall lightning protection in intelligent buildings, is characterized by the following: 1. Based on the importance of the building, its intended use, the likelihood of lightning strikes, and the potential consequences thereof, building lightning protection is divided into three categories according to specific requirements. The corresponding requirements for lightning protection measures in each category of buildings are specified in GB50057-94. 2. Antenna lightning protection facilities: When antennas are installed on the roof of a building, they must be connected to the building’s lightning protection grounding system. The protruding parts of these connections should extend beyond the building’s lightning protection range; separate lightning rods should be installed, and they must be securely connected to the antenna’s lightning protection grounding system. For comprehensive lightning protection, lightning arresters should be installed on the antenna feedline system. 3. Lightning protection for pipes, wires, and cables entering and leaving a building: All kinds of metal pipes, cables, and connection wires that enter or leave a building should be connected to the building’s lightning protection grounding system at the points of entry and exit ； At the entry and exit points of the cables, the power supply’s metal shielding, steel sleeves, etc., should be connected to the grounding of the electrical equipment. For example: when converting a cable to an overhead line, a lightning arrester should be installed at the conversion point. 4. Protection of information systems: Treat different parts separately and handle them properly. 5. Protection for the power supply system: Electronic surge arresters are used to provide hierarchical protection, covering high-voltage cabinets, low-voltage cabinets, main distribution boxes, and sub-distribution boxes, thereby reducing lightning overvoltage to a level that the equipment can tolerate. According to historical statistical analysis, in incidents of equipment damage caused by lightning strikes, over 70% occur as a result of intrusions through the power supply lines. Therefore, implementing multi-level lightning protection for these power supply lines is an important aspect of protecting electronic equipment and the entire system from lightning hazards. 6. Protection of electronic devices: Adopt appropriate comprehensive preventive and control measures by analyzing the various ways in which lightning pulses can affect electronic devices. Regarding lightning protection for the entire low-voltage electrical system, in general, the measures that can be taken include: implementing equipotential bonding of the system equipment ； Use metal pipes for wiring ； Strengthen shielding to reduce induction effects ； Implement equipment shielding, machine room shielding, and building shielding ； Install electronic surge protectors to limit the amplitude of lightning overvoltage that intrudes into electronic devices. Grounding of low-voltage systems: Grounding is a common issue in smart buildings. Based on its function, it can be divided into two main categories: functional grounding and protective grounding. 1. Functional grounding includes: system grounding, operational grounding, logic grounding, and shielding grounding. 2. Protective grounding includes safety grounding, lightning protection grounding, static electricity grounding, etc. Building grounding can be further divided into independent grounding and connected grounding based on the connection method. Independent grounding involves setting up the DC grounding, protection grounding, and lightning protection grounding separately. The purpose of doing this is to eliminate interference sources from the ground wire ； These are grounding measures taken in accordance with the requirements of computer systems for separate grounding, or those of communication systems for independent grounding. To prevent different potentials from arising due to the grounding of various systems, which could lead to accidents involving people and equipment, regulatory requirements specify that the distance between different grounding systems must be greater than 20 M. Moreover, their grounding electrodes and ground wires must be insulated, with an insulation resistance of over 2 MΩ, and the grounding resistance must be less than 4 Ω. Common grounding involves connecting various types of grounds to the same grounding device through grounding wires. Unless under special circumstances, a single building generally should have only one grounding system to prevent different potentials from being introduced, which could lead to accidents involving people and equipment. Therefore, in smart buildings, unless there are special requirements, the building’s grounding should adopt combined grounding for the low-voltage systems. Interference resistance of low-voltage systems: There is a large amount of electromagnetic interference in the natural environment outside buildings and complex buildings, as well as within their interiors; this can cause errors, misinterpretations, and abnormal operations in intelligent systems ； It contaminates the signal system and generates noise. Intense pulse interference can also cause damage to devices and equipment ； In actual operation, it is common for equipment performance to decline and for it to become unable to function ； It is necessary to purify the electromagnetic environment to prevent interference from stray electromagnetic waves and to enhance the anti-interference capability of systems and equipment. Therefore, interference resistance has become an essential technical measure for low-voltage systems. To this end, it is necessary to understand the causes of interference, analyze the sources of interference, comprehend the pathways through which interference spreads, as well as the measures and methods for counteracting interference. The sources of electromagnetic interference are divided into natural interference and human-induced interference. According to statistical analyses of relevant data, for computers and application computing instruments, the most harmful interference signals are spike pulse signals and damped vibration signals, as they can cause program errors, data loss, and even system damage. Interference mechanisms: Whether it is interference originating from within the equipment or the system, it affects the equipment through capacitive coupling, inductive coupling, electromagnetic wave radiation, as well as via conduction along common impedances and wires; it is the conduction along common impedances and wires that causes interference to the equipment. Therefore, the methods for eliminating and suppressing interference include electric field shielding, magnetic field shielding, electromagnetic shielding, grounding of electronic devices, and filtering. Common measures include: 1. Installing low-pass filters at the power supply’s input and output ports to eliminate high-frequency interference from the power grid ； 2. To prevent overvoltage caused by sudden changes in the mains power supply or lightning strikes, it is recommended that smart devices be powered by series-type voltage stabilizers ； 3. To suppress interference caused by grounding and common impedance, the method is to prevent circuits from forming between different grounds ； 4. The low-voltage system room should be located far away from high-power transmitters and elevator rooms ； 5. Determine the effective shielding method based on the level of electromagnetic field interference in the surrounding environment ； 6. Grounding of cable shielding layer ； 7. Use optocouplers and light transmission to transmit digital signals ； 8. Maintain electrical continuity of the rebar within the building structure ； 9. Install a power line filter on the power supply circuit of the lighting fixture, and shield the power terminals ； 10. Separate the circuit to be interfered with from the interfering circuit.