Engineering Standards for Urban Road Lighting Projects of the People's Republic of China Specification for Construction and Inspection Of Urban Road Lighting Engineering CJJ89-2001 Chief Editor: Beijing Street Light Management Office Approval Department: Ministry of Construction of the People's Republic of China Implementation Date: November 01, 2001 (Continued) 6 Safety Protection 6.1 General Provisions 6.1.1 The live parts of electrical equipment shall be protected against direct touch protection. Insulation measures may be used when screen protection is provided. 6.1.2 The following metal parts of the electrical installation shall be connected to zero or ground: 1 metal base or casing of transformer, power distribution cabinet (box, disk), etc. 2 metal frame of indoor and outdoor power distribution equipment and metal close to the charged part Obstruction and metal doors; 3 metal sheaths, junction boxes and protective tubes for power cables; 4 metal towers for distribution and streetlights; 5 other exposed conductors that may be charged due to insulation damage. 6.1.3 Do not use snake skin tube, bare aluminum wire and cable metal sheath layer as grounding wire. The grounding wire must not be used for other purposes. 6.2 Zero and grounding protection 6.2.1 In the low-voltage network of street lamps directly grounded at the neutral point, the outer casing of electrical equipment such as metal poles and distribution boxes should be protected by low-voltage zero. 6.2.2 In the protection zero system, when the fuse is used as the protection device, the single-phase short-circuit current should not be less than 4 times the rated fuse current of the fuse; when the automatic switch is used as the protection device, the single-phase short-circuit current should not be less than automatic. The switch instantaneously or delays the action current by 1.5 times. 6.2.3 When zero-connection protection is adopted, the single-phase switch shall be installed on the phase line, and the switch or fuse shall not be installed on the protection zero line. 6.2.4 The material of the protection neutral line and phase line should be the same. When the cross section of the phase line is 35mm2 or less, the minimum cross section of the protection neutral line should be 16mm2; when the cross section of the phase line is above 35mm2, the minimum of the protection zero line The section shall not be less than 50% of the section of the phase line. 6.2.5 When the protection is connected to zero, the grounding device shall be installed at the branch, the first end and the end of the line. The grounding resistance of the grounding device shall not exceed 10Ω. 6.2.6 Low-voltage grounding protection may be used when there is less electricity and equipment, and it is difficult to use zero-connection protection and the soil resistivity is low. 6.2.7 When the metal power equipment such as the light pole and distribution box is grounded, the grounding resistance should not exceed 4Ω.
1 2 3 Next Page
10th Laptop
Some client may feel that 10th Laptop is little old, so prefer 11th Laptop or 12th laptop. However, you will the 10th cpu is even more powerful than 11th, but price is nearly no difference, especially you take in lot, like 1000pcs. As a professional manufacturing store, you can see Laptop i3 10th generation 8gb ram,i5 laptop 10th generation, intel i7 10th gen laptop, etc. It`s a really tough job selecting a right one on the too many choices. Here are some tips, hope help you do that easier. Firstly, ask yourself what jobs you mainly need this Gaming Laptop to do. Secondly, what special features you care more? Like fingerprint, backlight keyboard, webcam rj45, bigger battery, large screen, video graphics, etc. Finally, ask the budget you plan to buy gaming laptop. Thus you will get the idea which laptop is right one for you.
Except integrated laptop, also have graphic laptop with 2gb or 4gb video graphic, so you can feel freely to contact us anytime and share your basic requirements, like size, cpu, ram, rom, video graphics, quantity,etc. More detailed value information provided in 1-2 working days for you.
10th Laptop,Laptop I3 10th Generation 8gb Ram,I5 Laptop 10th Generation,10th Generation Laptop,Intel I7 10th Gen Laptop
Henan Shuyi Electronics Co., Ltd. , https://www.shuyielectronictech.com