Click the blue word above to pay attention, and send you a free copy of excellent materials and excellent books Construction quality of Construction Engineering Project of creating Luban Award Common problems in construction project management Standardization guidance series Process boutique Guide Model Collection Series 1 basic requirements (1) the production and manufacture of distribution box (cabinet) shall meet the special requirements of low voltage switchgear and control equipment (Part IV, gb7251.4) for building site complete sets of equipment (ACS) and the standard requirements of technical code for safety of temporary electricity use on construction site (JGJ46-2005)（ 2） The installation and use of distribution box (cabinet) and switch box shall meet the standard of JGJ46-2005 technical code for safety of temporary electricity use on construction site and the standard requirements of GB / t13869 guide for safety of electricity use（ 3） The distribution box (cabinet) and switch box shall be provided with n-line and PE line terminal boards, and the incoming and outgoing lines must be reliably connected through the terminal board
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The n-wire terminal board must be insulated from the metal electrical installation board; PE line terminal board must be electrically connected with metal electrical installation board
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The n-wires in the in and out wires must be connected through the n-wire terminal board; PE line must be connected through PE line terminal board
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The connection between PE line and terminal board must adopt electrical connection
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The number of electrical connection points should be 2 more than the number of circuits in the box
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One is the connection point of PE line into the box, and the other is the connection point of repeated grounding（ 4） The electrical components shall meet the standards of GB / 14048.2-2001, gb6829 and JGJ46-2005, and meet the technical requirements of the Eleventh Five Year Plan of the Ministry of construction
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2
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The main distribution box (cabinet) is equipped with 400a-630a DZ20 transparent molded case circuit breaker with isolation function as the main switch, and 4-8 channels are set in the branch circuit
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DZ20 series 160a-250a transparent molded case circuit breaker with isolation function is used, and dz20l (DZ15L) transparent leakage switch or lbm-1 series are configured as the leakage protection device, so that it has the functions of under voltage, overload, short circuit, leakage and open phase protection, At the same time, it is equipped with watt hour meter, voltmeter, ammeter and two sets of current interchangers
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The product of rated leakage action current and rated leakage action time of leakage protection device shall not be greater than 30mA
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S
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It is better to select the rated leakage action current of 75-150ma, the rated leakage action time is greater than 0.1s and less than or equal to 0.2S, and the action time is delay action type
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Schematic diagram of general distribution cabinet terminal board contact diagram of general distribution cabinet door electrical connection point diagram of four circuit distribution cabinet electrical system diagram of six circuit distribution cabinet electrical system diagram of eight circuit distribution cabinet electrical system diagram 3 distribution box (I) including lighting circuit distribution box (power circuit and lighting circuit distribution) with 200a-250a transparent molded case circuit breaker with isolation function As the main switch (adapted to the setting of circuit breaker in the main distribution box); DZ20 or KDM-1 transparent molded case circuit breaker is used as the control switch of power shunt and lighting shunt; DZ20 or KDM-1 transparent moulded case circuit breaker is used as control switch in each distribution circuit; PE line connection bolts and N line connection bolts shall be configured according to actual needs
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Schematic diagram of distribution box Electrical connection diagram distribution box electrical system diagram including tower crane circuit distribution box schematic diagram (terminal board contact and electrical connection point diagram as above) including tower crane circuit distribution box system diagram (2) excluding lighting circuit distribution box 6-8 circuit distribution box schematic diagram 6-loop distribution box including tower crane circuit (terminal board contact and electrical connection points are the same as above) 8-loop distribution box system figure 6-loop distribution box system including tower crane circuit figure 4 switch box (one machine, one switch, one leakage) (I) kdm1 or DZ20 (above 160A, 380V) series transparent molded case circuit breaker is set as control switch in power switch box of large equipment such as ground pump, Dz20l series transparent leakage circuit breaker or lbm-1 series leakage circuit breaker are equipped; The terminal block of PE line is made up of 3 connecting bolts
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Schematic diagram of switch box for ground pump and other large equipment electrical system diagram of ground pump and other large equipment (2) power switch box for tower crane and other equipment, and the configuration is the same as the schematic diagram of power switch box for tower crane and other equipment System diagram of tower crane and other power equipment switch box (III) DZ20 (20-40a, 380V) or se, kdmi series transparent molded case circuit breaker is set in the switch box of electrical equipment below 3.0kw as the control switch, dz15le (20-40a) or lbm1 series transparent leakage circuit breaker is configured, and PE line terminal block is 4 connecting bolts
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Schematic diagram of power switch box below 40A terminal contact and electrical contact connection diagram of power switch box Electrical system diagram of electrical switch box for equipment below 40A (IV) control switch and leakage circuit breaker for electrical switch box for equipment above 5.5kW shall be selected according to rated capacity of controlled equipment
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The control switch is DZ20 (Se or kdm1) series transparent molded case circuit breaker, and the residual current circuit breaker is DZ15L series transparent residual current circuit breaker; There are 3 connecting bolts for PE line
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Schematic diagram of switch box for equipment above 5.5kW electrical system diagram of switch box for equipment above 5.5kW (V) kdm1-t / 2 (20-40a) circuit breaker, dz15l-20-40 / 290 leakage circuit breaker and three PE line bolts are set in the lighting switch box
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Lighting switch box schematic diagram lighting switch box electrical system diagram note: the leakage circuit breaker in the switch box must select the rated leakage action current not more than 30mA, the rated leakage action time not more than 0.1s, the current quick break, electromagnetic motor protection products
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The residual current circuit breaker in the main distribution box shall be used for distribution protection
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The layout of the distribution room shall meet the following requirements: (1) the width of the operation channel on the front of the distribution cabinet shall be no less than 1.5m for single row or double row back-to-back layout, and no less than 2m for double row face-to-face layout（ 2） The width of the maintenance channel behind the power distribution cabinet shall be no less than 0.8m for single row or double row face-to-face arrangement, and no less than 1.5m for double row back-to-back arrangement
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If there is a protruding part of the building structure in some places, the channel width at this point can be reduced by 0.2m（ 3） The width of maintenance channel on the side of distribution cabinet shall not be less than 1m（ 4） The distance between the ceiling of the distribution room and the ground shall not be less than 3m
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The erection of distribution box shall meet the following requirements: (1) the vertical distance between the center point of fixed distribution box and switch box and the ground is 1.4-1.6m
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The vertical distance between the mobile box and the ground is 0.8-1.6m
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The distribution box and switch box shall be installed on solid and stable support（ 2） The distribution box and switch box within the falling radius of the building or the rotating radius of the tower crane arm must be provided with double-layer protective shed, and isolation measures shall be taken.
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