1. When the shielding system is used to support integrated wiring in an environment with serious interference, a full shielding system should be adopted, and the shielding layers of all wires should be well connected in one plane. This can effectively reduce the introduction, coupling and propagation of electromagnetic interference.
2. For systems above100 MHz, the shielding efficiency is required to be above 50 ~ 70 dB. The shielding system composed of grounded and ungrounded integrated wiring system is desirable. As long as enough parallel coupling channels are ensured, good shielding effect can still be obtained.
3. When using shielded cable, the grounding of shielding layer should be correct, reasonable and safe. Usually, one-point grounding is adopted, and multi-point grounding is not allowed to avoid forming a current loop. At the same time, it is necessary to ensure good contact at the connection of shielding layer, otherwise new interference sources will be introduced.
4, shielding wiring system should meet the requirements of fire prevention. Shielding materials are usually flame retardant, but not all materials meet the requirements of fire resistance. In case of fire, even if the metal sheath of the cable is not damaged, the cable may be short-circuited in the flame. Therefore, the shielded wiring system should comply with the relevant regulations and requirements of fire safety in this project.
5. Shielded wiring system should have a good protective effect on the influence of electrical radiation interference of power supply, pipelines and equipment. When using shielded cable wiring system on AC power lines, special attention should be paid to avoid the formation of electromagnetic induction loop, so as not to generate induced voltage and affect the normal operation of equipment.
6. When selecting the shielding wiring system, we should also consider the radiation intensity and attenuation of electromagnetic field, as well as the types and intensity of interference sources, which will affect the effect of shielding system.
Selection and protection measures of electrical protection equipment for integrated wiring system
1, lightning protection and grounding equipment: lightning protection and grounding equipment are very important in the integrated wiring system. Usually choose good quality lightning protection devices, such as lightning arresters and lightning rods. These devices can effectively prevent lightning from damaging the integrated wiring system. At the same time, grounding equipment with excellent performance should be selected to ensure that the current can flow back to the earth smoothly. Grounding equipment usually includes grounding wire, grounding electrode, etc. , and should be correctly installed and reasonably arranged to meet the electrical safety specifications.
2. Isolation equipment: In the integrated wiring system, isolation equipment is also essential. Electrical isolators or filters with reliable quality should be selected to reduce the influence of electromagnetic interference. These devices can effectively isolate strong electrical signals from the integrated wiring system, thus protecting the stability and security of the integrated wiring system.
3. Anti-static equipment: The integrated wiring system should be equipped with anti-static equipment to prevent static electricity from damaging the integrated wiring system. Equipment such as anti-static floor and anti-static wires with excellent performance should be selected to ensure the stable operation of the integrated wiring system.
4. Anti-electromagnetic interference equipment: The integrated wiring system should be equipped with anti-electromagnetic interference equipment to prevent electromagnetic interference from affecting the integrated wiring system. Shielding equipment with strong electromagnetic interference resistance, such as shielded cable and shielded network cable, should be selected to ensure the stability and reliability of the integrated wiring system.
5. Protective measures: Besides selecting appropriate protective equipment, corresponding protective measures should be taken. For example, the integrated wiring system should be inspected and maintained regularly to ensure its normal operation; The integrated wiring system should be arranged reasonably to avoid interference between strong and weak signals; Ensure that the grounding equipment is well grounded to prevent the current from damaging the integrated wiring system; The transmission medium, such as shielded cable or network cable with strong electromagnetic interference resistance, should be reasonably selected to ensure the stability and reliability of the integrated wiring system.