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Installation Instructions of Infrared Explosion Proof Camera
Installation Instructions of Infrared Explosion Proof Camera(1) product selection must meet the safety standards for the use of places, such as explosion-proof type and flameproof level, group.
In the area of gas or vapor explosive mixtures, the level and temperature group of the explosion-proof electrical equipment must be selected in accordance with the principle of the class and group of explosive mixtures. When there are two or more different levels, the explosive mixture of the group, should be more dangerous level and the selection of the appropriate level of explosion-proof type.
(2) the industrial environment is usually harsh environment, high temperature, high noise, heavy dust, chemical acid corrosion, chemical severe alkali corrosion and other poor production conditions of the product quality is a major test. So the accurate selection of equipment is essential, low-end products despite the cheap procurement, but count the maintenance costs, the total cost is not much lower than the high-end products, especially in case of accident, count the aftermath of the cost and Criminal responsibility is really not money.
(3) some petrochemical plant corrosive gases and liquids are more serious, should choose stainless steel explosion-proof camera and regular maintenance is appropriate.
(4) explosion-proof camera with safety hazard can not be used, such as the lack of fastening screws, the cable into the device seal without compression device or seal has been lost, the explosion surface wear, the nameplate has been seriously corroded or lost.
(5) the use of outdoor explosion-proof camera must have a strong waterproof performance.
(6) explosion-proof products with signs and signs, the general explosion-proof electrical products are equipped with a clear "Ex" permanent logo, which is a common explosion-proof electrical products logo, not the product explosion-proof signs, explosion-proof signs displayed on the product signs. Signs are made of copper. Name of the nameplate In addition to the product model, specifications, manufacturer name, factory date or factory number, there are "Ex" signs, explosion-proof signs and explosion-proof certificate number. Mine explosion-proof electrical products to have "Ex" logo, "MA" signs, explosion-proof signs and explosion-proof certificate number, MA coal mine safety signs Zhunsan Zheng number.
(7) from abroad to introduce explosion-proof electrical products must be approved by China's explosion-proof quality inspection agencies.
(8) carefully identify fake and shoddy products.
Mainly for the nameplate on the explosion-proof certificate number, forged explosion-proof certificate number, no manufacturers and rough work fake and shoddy products.
Explosion-proof camera installation points
Electrical installation of the explosive environment, in principle, according to GB50058-92 "explosion and fire hazard location power design technical specifications", GB 50257-96 "electrical installation of the project explosion and fire hazard electrical environment construction and acceptance of electrical norms", CD90B-85 " Explosive atmospheres for wiring and installation of electrical equipment General drawings ", IEC 79-14, 19966 Electrical equipment for explosive gas atmospheres - Part 14: Electrical installation in hazardous areas". However, the electrical installation of hazardous locations should first meet the requirements of the general electrical installation specifications, that is, the electrical installation of hazardous locations, after reaching the general electrical installation specifications, but also to meet the special requirements of the above criteria. For example: general electrical installation, black tape is widely used insulation bandaged material, but in dangerous places are not allowed to use. Must be insulated dressing place, requiring the use of self-adhesive tape bandage. Electrical installation of dangerous places should be safe, in dangerous places as little as possible the use of electrical products, installation location also requires to avoid the release source, to avoid the process of pipe heat, water, vibration and other effects.
Low - voltage Wiring Construction in Class 1 Dangerous Area
First, the wiring method
Class 1-1 hazardous areas within the low-voltage wiring construction requires a flame-proof metal pipe construction or cable construction. Mobile electrical equipment (devices that are used frequently or intermittently) shall be of a neoprene insulated cable with a grounding wire or other cables of the same performance.
Class 1-1 hazardous areas within the electrical wiring requirements in case of grounding, short circuit and open circuit and other accidents, it will not form a detonating source. To this end, in the metal pipe wiring, from the electrical equipment to the junction box to the danger zone or non-hazardous areas at the junction of the seal between the line of the line, are required to make the structure of the pipeline explosion-proof structure.
In addition, the 1-1 area dangerous area, can also be used cable wiring. Since the wiring accident occurs mainly at the end of the cable connection, therefore, in addition to the end of the cable into the flameproof junction box, but also select the appropriate cable with the laying to avoid external damage.
Second, the external wiring and electrical equipment connection
External wiring and electrical equipment connection, in principle, the use of flameproof junction box.
1, the introduction of flameproof thread
In accordance with the provisions of the explosion-proof regulations, the introduction of wire tube is cylindrical pipe thread connection. The effective part of the thread should be engaged in the 6 buckle or more, to meet the "thread explosion" technical requirements. To ensure complete thread engagement, use nuts to lock.
2, explosion-proof filler introduction
The so-called explosion-proof filler into the way, refers to the insulated wire through the shell wall with a filler seal to achieve the role of explosion.
Generally used asbestos, glass fiber, synthetic rubber, or other materials with appropriate elasticity, heat resistance and better insulation. In the packing gland on the outside with a cable plate and cable protection tube, to avoid the part of the filler by external force damage.
The introduction of steel-clad type armored cable (including corrugated steel pipe armor) with flameproof packing shall be stripped of the coating and strip sheathed through the junction of the junction box.
3, the introduction of flameproof seal
Explosion-proof type of introduction of the seal, is to fill the packing filler to the insulated wire through the wall part, so that through the wire was fixed. This method is only applicable to low voltage circuits. The physical and chemical properties of the mixed filler are required to be softened at the use temperature after solidification without cracking cracks and no adverse effects on the through wires.
The introduction of rubber or plastic cable outlet box at the entrance, the seal should be kept flameproof performance, at the same time, must also be installed cable protection tube. The filling depth of the sealed mixed packing shall be 1.5 times or more of the cable introduction diameter (minimum 40 mm). There shall be a mark indicating the amount of filling required in the mouth. A cable compression plate shall be provided at the inlet to allow the cable from the seal to be protected from pressure.
The shape and size of the mixed filling cavity shall be such that the mixed packing is fully adhered to the wire and the filling chamber wall. Fill the cavity of the wall should be convex and concave, so as not to harden the mixed filler off. Through the wire generally not more than nine. With the baffle, guide plate, etc. to be symmetrical display, through the wire were separated from each other, and the gap with the filling cavity wall, in principle, the diameter of the wire more than 1/2 (minimum 2 mm).
4, flameproof metal casing introduced way
Flameproof metal casing type, refers to the flange with a metal casing as the main body to press the ring and nuts made of pipe fittings. The secondary introduction is applicable to the level 1 and 2. Through the cable with a metal jacket with rubber insulated flexible cable, linen insulated cable, or vinyl insulated cable, can also use other equivalent performance of the cable.
The maximum permissible value of the gap between the inner surface of the metal sleeve and the outer circumference of the cable is 0.2 mm, the minimum allowable value of the gap length is 25 mm, and the inner diameter of the casing should be 0.15 mm below the standard outside diameter of the cable. The casing is machined into a cylindrical pipe thread and the junction box is threadedly connected to maintain its flameproof performance.
Third, the construction of flameproof metal pipe
Piping method
(1) threaded connection: wire and its accessories and electrical equipment outlet box connected to the general use of threaded connection (thread and pipe thread). The effective engagement of the threaded connection is 6 or more and is tightened tightly with the locking nut. The results show that the use of locking nuts will be tightened by one side of the thread to make the propagation path longer, and greatly improve the explosion-proof performance. However, when the two wire tube with a pipe connection, it is difficult to ensure that the thread is engaged with more than 6 buckles, and most of the threaded part exposed to the outside, the mechanical strength greatly reduced. Therefore, in this case the use of joint section connection is most appropriate. In the case of corrosive gas or water vapor, intrusion of the nuts from the nuts causes corrosion of the piping threads or aging of the piping and equipment. In order to avoid the occurrence of the above phenomenon, generally in the threaded part of the liquid filler or non-hardened preservative, and then engage.
(2) flexible connection: the need for flexible connection of the piping, you must use the flameproof structure of the flexible joints. And the inner radius of the joint bent portion is 5 times or more of the outer diameter of the flexible joint.
3. Sealing technology requirements
In order to prevent the flame caused by the explosive gas or explosion, through this part of the device from the part of the channel to another part of the pipeline, or in the pipeline should be filled with mixed packing, so that sealed with each other.
The following highlights the layout of the metal pipe with a flameproof structure, the installation of sealing joints requirements.
Sealed joints
When the wire line through the 1-1 level dangerous area and other areas between the partition wall, the sealing joint can be located in any side of the partition, but in the sealing joints and partitions between the wire tube can not be connected Sewn. The sealing joint on the wire tube of the Class 1 hazardous area and other area spacing walls may be provided on either side of the partition wall, but when the vertical pipe passes through the top of the flap, it is preferably provided on the outside of the partition , Runs through the bottom of the place, preferably on the inside of the partition. Take these measures, mainly taking into account the vertical seal joints filled with mixed filler, the external explosive material may also be part of the upper wire through the threaded connection part of the wire tube, in case of high concentrations of explosive gas, the gas through the wire The tube is installed in a general type of electrical equipment installed in a non-hazardous area.
2 inch or more of the wire tube in the sealed joints
In principle should be installed in the junction box or with other boxes within 45 cm, and as close as possible. Mainly to take into account the larger diameter of this wire tube, junction box or box volume is also large, if the junction box or box within the explosion, the pressure is quite large. If the seal is applied in the vicinity to reduce the volume of the pipe, then the pipeline will not bear more pressure. Therefore, the distribution board, distribution board and other junction box, and connected with the connection box of the wire tube, sealing joints, etc. should be installed in the near as far as possible.
(1) the filling requirements of the sealed mixed packing
Fill the sealed mix of fillers as far as possible. Seal the inner wall of the connector or the wire, often with a broken fiber. If the treatment is improper, these fine fibers are very easy to cause leakage, it must be so that the lines and mixed filler completely affixed to the wire cover and seal the inner wall of the joint. In any case, the effective length of the filling layer shall not be less than the inner diameter of the wire (minimum 20 mm). Fill the filler is completed, to confirm that has been fully meet the requirements, and then tightly screwed into the filling port.
Fourth, cable construction
Before the construction, according to the use of non-corrosive substances, the presence of mice, termites, the impact of ambient temperature and the junction box lead and end processing operations such as the difficulty of selecting the appropriate cable, such as rubber, plastic jacket cable , Or metal armored cable. In the case of corrosive gases or liquids, the use of cables must be considered corrosion.
The introduction of flameproof packing way, the cable into the junction box, the cable cross-section should be round, the sheath surface shall not have uneven phenomenon.
1, cable laying method
When laying cables, take full account of the protection of the cables, the bending of the cables and the prevention of the flow of explosive gases in the cable lines. When setting up the cable, in principle, the cable should be placed in the steel wire tube, or put into the appropriate protective device and then laying, so as not to be traumatized. Protection tube diameter, the general requirements for the cable diameter of more than 1.5 times. Determine this value, mainly to prevent damage to the cable when introduced. If the protection of the pipeline is not short to prevent threading, it can be smaller than this value. An armored cable protected by a steel belt, such as a place where it is less susceptible to external damage, may also be protected.
2. Cable connection
In the explosion hazard area, the cable and cable can not be connected directly in principle. However, in special cases, the cable must be connected to the shunt connection, or cable and flameproof structure of the metal pipe connection, you can take the explosion-proof connection box connection. Explosion-proof connection box structure, there are explosion-proof and increased safety, the use should be consistent with the requirements of explosion-proof performance.
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