(2) The production and installation of distribution boxes and switch boxes shall meet the following requirements:
1 Distribution box is made of iron plate or other fireproof insulation material to achieve ventilation, heat dissipation, rainproof and fireproof;
All kinds of electrical appliances in the box should be installed on metal or other insulating boards (non-wood boards) and fastened in the box. The metal base plate shall be electrically connected to the cabinet;
3 Normally uncharged box metal casing, base and so on must be connected to zero (ground), and connected through special terminals, and separated from the protection neutral terminal block. Each electrical connection line shall be insulated conductor, the joint is reliable and shall not be exposed;
4 Inlet and outlet lines must be rubber insulated cables. The inlet and outlet ports should be placed on the lower end of the box and a protective ring should be added. The inlet (outlet) line should be made waterproof and not subject to external forces.
(3) The rated value and action setting value of the main distribution box electrical appliance should be compatible with the rated value and action setting value of the shunt switchgear. It is equipped with a total automatic switch, leakage protector and shunt automatic switch.
(4) The various electrical components and leakage protectors used in the distribution boxes of all levels shall meet the quality requirements of the national standard.
(5) The leakage protectors in the distribution boxes of all levels should be arranged reasonably to play the role of classification and segmentation protection.
(6) Leakage protectors should be used strictly in accordance with the product specifications, and regular tests and operational records should be made. For those that have been idle for a long time and have been used continuously for more than one month, they should be inspected and tested before they can be used.
(7) Installation of current type low voltage electric shock protectors shall meet the following requirements:
1 The electric shock protector should be intact, the action is sensitive and reliable, and should be reasonably selected according to the actual load current;
2 Protected lines and electrical equipment should be well insulated, and the current level of the electric shock protector should be correctly selected;
3 The wires that pass through the electric shock protector should be twisted together, wrapped with a tape or tape, and placed in the center. The bundle should not be scattered within 200mm before and after the touch protector;
4 The electric shock protector should be away from the AC electromagnetic field, such as transformers, current transformers, motors, etc., and the installation distance of the AC contactor with this should be 400mm;
5 Through the neutral line after the electric shock device, the grounding must not be repeated, only the working zero line is allowed, and the metal casing of the protected electrical equipment should be protected grounding;
6 If the protection is connected to zero, the protection zero line should be led from the front of the electric shock protection switch.
(8) Each electrical equipment should have a special switch, and “one machine and one gate†must be implemented. It is strictly forbidden to use one gate.
(9) Manual switchgear is only approved for direct control of lighting circuits and power circuits with a capacity of less than 3kw. All kinds of boxes should be clearly responsible for the regular inspection, maintenance and cleaning work.
(10) When the distribution box is inspected and repaired, the power switch corresponding to the previous level must be cut off and the eye-catching “blackout and maintenance†sign should be hung.
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