Explosion-proof camera installation points

One of the key points of installation of explosion-proof cameras--Selection of explosion-proof cameras:

First of all, the selection of explosion-proof surveillance camera products must meet the safety standards of the place of use, such as the type and type of explosion-proof type and explosion-proof type. When there are two or more explosive mixtures of different grades or groups in the area, the appropriate explosion-proof type should be selected according to the level and group with higher degree of danger. Some petrochemical plants have severe corrosive gases and liquids. Explosion-proof cameras made of stainless steel should be selected. Explosion-proof cameras with safety hazards must not be used, such as missing fastening screws, sealing rings of cable entry devices, no pressure devices, or missing sealing rings. , Explosion-proof surface wear, nameplate has been seriously corroded or lost; explosion-proof cameras used outdoors must have strong waterproof performance; explosion-proof products have signs and signs, and signs (nameplates or warning signs) are made of copper. In addition to the product model, specifications, manufacturer's name, date of manufacture, or factory number, the contents of the tag include the “Ex” mark, explosion-proof mark, and explosion-proof certificate number. Mine explosion-proof electrical products must have "Ex" mark, "MA" mark, explosion-proof mark and explosion-proof certificate number, MA coal mine safety mark permit certificate number; explosion-proof electrical products imported from abroad must pass inspection and approval of China's explosion-proof quality inspection agencies ; Carefully identify fake and shoddy products. The main performance is that there are no explosion-proof certificate number on the signboard, forged explosion-proof certification number, no manufacturer, and rough workmanship.

Explosion-proof camera installation points two - explosion-proof camera installation pipeline installation:

During the installation of explosion-proof cameras, the construction of low-voltage wiring in explosion-proof hazardous areas requires the use of flameproof metal pipe construction or cable construction. Movable electrical equipment (means that are used for frequent or intermittent movements) should use neoprene insulated cables with grounded conductors or other cables with the same performance. In the metal pipe wiring, the wire line between the junction box of the electrical equipment and the sealing joint provided at the boundary of the 1-2 hazardous area or the non-hazardous area must be made into an explosion-proof structure. In addition, cable routes can also be used in Class 1-1 hazardous areas. Since accidents in wiring mainly occur at the connection points at the end of the cable, in addition to installing the cable end into the flameproof junction box, cables suitable for laying are also selected to prevent external damage. Connection of external wiring and electrical equipment Flameproof thread introduction method: The effective part of thread engagement should be guaranteed to be more than 6 deductions, and it must meet the technical requirements of “thread explosion-proof”. To ensure complete thread engagement, tighten with a nut.

Explosion-proof camera installation points three - flameproof filler introduction method:

Explosion-proof surveillance cameras are sealed with stuffing in the insulated wire through the shell wall to achieve explosion proof. Asbestos, glass fibers, synthetic rubber, or other materials having suitable elasticity, heat resistance, and good insulation properties are generally used. Cable glands and cable protection tubes are installed on the outside of the packing gland to prevent the packing from being damaged by external forces. When the strip-type armored cable (including corrugated steel pipe armored cable) is introduced in the explosion-proof packing type, the anti-corrosion layer and the steel strip armouring shall be stripped through the introduction port of the terminal box. The introduction of flameproof encapsulation: The introduction of flameproof encapsulation means that the mixed filler is filled into the insulated wire through the wall, so that the through wire is fixed. This method is only suitable for low voltage loops. The introduction of rubber or plastic cables at the entrance of the outlet box should maintain its explosion-proof performance. At the same time, cable protection tubes must also be installed. The filling depth of the sealed mixed packing should be 1.5 times more than the cable entry diameter (minimum 40 mm). There should be a mark in the inlet that indicates the required amount of filling. Cable glands should be provided at the inlet to protect the sealed cable from stress.

During the installation of the explosion-proof camera, the structure and size of the mixed filling cavity should be such that the mixed packing can fully adhere through the wire and fill the cavity wall. The inner wall of the filling chamber should be convex and concave so as to prevent the hardened mixed filler from falling off. The penetration wire must not exceed 9 in general. The baffles, guide plates, etc. shall be arranged symmetrically as far as possible, and the distances between the through wires shall be separated from each other and with the inner wall of the filling chamber. In principle, the outer diameter of the wire is 1/2 or more (minimum 2 mm). Flameproof metal sleeve type introduction method: refers to the flanged metal sleeve as the main body, with the compression ring and nut consisting of pipe fittings. The secondary introduction method is applicable to the 1st and 2nd impostors. Through-cables use rubber-sheathed flexible cables with metal sheathing, fine linen insulation cables, or vinyl-insulated cables, and other equivalent cables may be used. The maximum allowable value of the gap between the inner surface of the metal sleeve and the outer circumference of the cable is 0.2 mm in diameter, and the minimum allowable gap length is 25 mm. The inner diameter of the sleeve should be 0.15 mm or less than the standard outer diameter of the cable.

All in all, the installation of explosion-proof cameras is more complex than the conventional surveillance cameras. In addition to the monitoring and acquisition itself requires a qualified manufacturer of explosion-proof camera brand, in the selection and cable laying should be done explosion-proof isolation measures.