Summer thunderstorms explosion-proof, grounding lightning protection instrument do?

Summer thunderstorms; Lightning protection, explosion-proof instrument grounding in how to do it; Combined with standard instrument and meter plant to take you to go grounding technology were originally introduced to prevent electric or electronic equipment from lightning protective measures, aims to introduce the thunder of lightning current generated by lightning rod to the earth, and so to protect the building. At the same time, the earth is also a kind of effective means to protect the safety of person. Now, with the development of computer and automation control technology, various kinds of electronic equipment become an integral part of industrial production, so the correct reasonable ground has become a important basis for the industrial production safety and reliable. So all need what kinds of grounding in industrial production? The design requirements is what? Katie today according to HG/T20513 - instrument equipment factory 2014 'instrument grounding system design specification' learning instrument grounding those things. Protect the grounding protection is generally expressed in PE. Safety grounding is will not charged metal parts (system normal Such as cabinet shell, work station of the shell, etc. ) And to form a good electrical connection between, in order to protect the equipment and personal safety. Reason is the power of the system is high voltage power supply, chassis, etc are not normally charged, when the failure occurred ( Such as the host power failure or other failure) Caused by the power of the power supply wire and shell conductive metal parts such as short circuit, the metal parts or shell charged body was created. If you don't have a good grounding, then this has a high potential difference between a charged body and ground. In this case, the person and equipment has a serious security hidden danger. Must, therefore, the metal casing and to make a good connection between the housing and land equipotential. According to HG/T20513 - 2014 the instrument grounding system design specification requirements, the need for protective earthing of equipment includes: 1. Work station of the dashboard, instrument, instrument cabinet, instrument and meter box; 2. Instrument control system cabinet and operating station; 3. The computer system cabinet and work station; 4. Power supply panel, power supply box, electric instrument shell, cable tray, protection tube, junction box and armoured shield layer, etc. In principle above 36 v power supply has protective grounding is required. Protect the grounding resistance value is not greater than 4 & Omega; , should not be the highest for more than 10 & Omega; 。 Working grounding work is a general designation, all instrument circuit grounding is called a working system to work normally. HG/T20513- 2014 working grounding can be divided into signal circuit grounding and shielding. Signal circuit grounding signal circuit is mainly for electronic equipment to establish a unified benchmark potential, such as the negative terminals of the transducer signal grounding, the negative terminals of the switch signals and grounding, etc. Can signal grounding connected to the power supply grounding directly, mainly according to the requirement of the system of signal shielding. When required by the system are shielded, signal grounding need to make corresponding processing. According to the relevant provisions of the standard signal circuit grounding should satisfy: 1. The separation of signals with the consent of the need to build a reference point, should carry on the signal circuit grounding ( Usually for dc power supply cathode) ； 2. Isolated signal can not grounding, should be each input/output signals and other input/output signal circuit is insulation, ground is insulation, power source is an independent and isolated from each other. Shielding grounding signal is a grounding, work as the main role is to prevent the high frequency electromagnetic interference signals of equipment internal circuit impact, through the electromagnetic interference shielding grounding way. Interference by interference sources from a digital circuit, circuit signals to analog signals, so the grounding also known as the shield of the analog signal. According to the standard, shielding grounding should satisfy: 1. Instrument to reduce electromagnetic interference in the system components, such as cable shielding layer and the drain line, instrument on the shielding earthing terminal shall be shielding grounding; 2. Outdoor overhead laying without shield ordinary multi-core cable can spare core; 3. Shielded cable shielding layer is ground, the standby can not grounding; 4. Wear protection tube of multi-core cable spare core can not grounded. Power grounding for electronic equipment in the power of the cathode, need access to the public for earth. The Ann grounding essence safety instrument system should not be a separate grounding systems, should be one with electrical grounding system. Safety barrier is divided in two types: the isolation and zener. Isolation type safety barrier by adopting the technology of isolation protection, do not need special ground, while the zener type safety barrier protection according to its working principle requires good grounding system. Safety grid grounding wires connected with the centerline of the ac power supply starting point of the most simple and reliable method is to use wire connection. The scene in the instrument is not grounded on the tip of the signal, the purpose of the instrument earthing is not to intrinsically safe. In addition, the potential effect only on the ground of the insulation of the transmitter, will not reach the level of insulation breakdown field instruments. Some literature on the transmitter enclosure grounding as a signal to end, and the shell to site for the dangerous sites with the zener type safety barrier to the potential difference between the ground point to discuss safety barrier breakdown is not correct. If the scene side of instrument signal is inherent grounding, loop forming two grounding, epd could effect on the security gate.