Technical measure on electrical works
Here are English study for Electric Knowledge, for your reference,
A. Process 施工工艺： Conduiting → cabling → installation of lighting fixtures, switches, sockets → power on and commisioning
配管 → 配线 → 安装灯具、开关、插座 → 送电调试
B. Construction notice 施工要点：
Ø Surface PVC conduit and pipe in ceiling and recessed PVC conduit and pipe in floor along walls will be provided to the project. Conduiting, which serves to civil works, HVAC and water supply and drainage, should be arranged according to drawings and can not be changed freely. Construction should comply to process standard of national acceptance regulation.
Ø Surface conduit and recessed conduit will be adopted in the project. Conduits should be connected tightly to assure no water leakage. Electrical pipe should be thread connected. Mouth of conduit should be smooth and equipped with protection mouth. PVC conduit should be connected by sleeving and should be 1.5 to 3 times longer than external diameter of connecting conduit.
Ø Bending radium of surface conduit should be 4 times no less than its external diameter and bending radium of recessed conduit should be 6 times no less than its external diameter. There is no obvious wrinkle caused by bending. Surface conduit and support should be fixed strongly and arranged into order. Mouth of conduit should be laid levelly. Conduit should not be inserted into box obliquely and the length in the box should be no more than 5mm. Conduit should be fixed by nut.
Ø All the boxes are not allowed to open holes by electrogas welding.
Ø It is noted that boxes should not be installed on marble table and behind doors and their height are same as each other. Lighting switches and sockets should be installed at same position of rooms, of which the error should be within 2mm.
Ø Steel frame or special hanger frame should be strengthened for installation of lighting on ceiling. Lighting fixtures should be installed without gap at joint and they will be kept clean.
Ø Switch controls neutral line, and phase line of screw holder is connected to power. Left point of socket should be connected to neutral line, right point to phase line and upper point to earth. Height of light should be lower than 2.4m, and the metal shell should be connected to earth well. Light switches, sockets should be fixed without damage and deforming.
Ø Power DB should be installed securely at right position with all parts. The holes should be opened properly on the box and prohibit to open holes by electrogas welding. The conduit inside box should be level and fixed by nut. Screw should be connected to earth well and 2 to 4 pieces of it can be outside.
Ø Box should be clean inside and outside with good painting. Wires should be arranged into order and bounded. Connection of wires should be right and fixed, meanwhile, spare wires should be kept. Number of card should be completed. The boxes should be installed with error no more than 1.5mm.
Ø Joint and connection of wires inside conduit is not allowed when they are threaded through conduit. Stranded copper core should be connected to equipments. Wires less than 6mm2 can be put like shape of screw eye and then coated by tin. Single-stranded copper core can be provided fire retardant safety wire joint or tin coat. Bobbin used by wire joint should be crimping tools of 3 point crimping type. Tin coat should be smooth, no damage to insulated layer of wire. Color of wire threaded through conduit: phase line is yellow and green; single phase is red; neutral is blue; earthing line is two-tone colored wire of yellow and green.
管内穿线严禁在管内接头，导线有连接，多股铜芯线应用铜线与设备连接，6平方毫米以下可做 “羊眼圈”状再刷锡。单股铜芯线可采用阻燃型安全压线帽或刷锡。压线帽使用的压线轴必须是专用配套的“三点抱压式”压接钳。刷锡应饱满、光滑、无损伤导线 绝缘层。穿线时的导线色标为：相线为黄、绿色；单相用红色为宜；零线为单兰色；接地线为黄、绿双色线。
Ø Compensating unit should be provided when wires thread through settlement joint and expansion joint of building. Insulation resistance between wire and earth should be no less than 0.5ΩM.
Ø Materials and equipments to be used should be provided with texture specification and certificate of qualification.
Ø Construction workers should be provided training about security and technology. Electrician should have qualified license.
u Installation of common lighting fixtures 普通灯具安装：
1、Lighting fixtures should be fixed according to following regulations
（1）、When the weight of light is more than 3kg, it should be fixed by screw or embedded lifting hook.
（2）、When weight of soft core light is less than 0.5kg, it should be hung by its soft wire. When the weight of soft core light is over 0.5kg, it will hung by sling chain with soft wire inside it so that the wire will be free from force.
（3）、Lighting fixture should not be fixed by wood screw. Screws or bolts used to fix lighting fixtures should be no less than 2 pieces. When insulated radium is less than 75mm, lighting fixture should be fixed by one screw or bolt.
（4）、Diameter of round steel of flower light’s hanging hook should be no less than that of hanger tenon and 6mm. Test of installing light twice heavier than flower light should be done before installation of large flower light.
（5）、When steel pipe is used as lamppost, interior diameter should be no less than 10mm and thickness no less than 1.5mm.
2、When height of lighting fixture is less than 2.4m, lighting fixture should be connected to earth well with special earthing bold and marks.
3、Shell, lamp holder and wire connection of lighting fixture should comply to requirements goes as follows.
（1）、Lighting fixture with full parts, no damage or deformation and no defects of coats flaking off or lamp shade tears.
（2）、Protection joint should be provided on the both end of soft wire of hanging light. Core wire of both end should be coated tin. Plastic soft tube and safety lamp holder should be used during riser installation.
（3）、Insulated shell of light holder is not damaged and electricity leakage. The handle of switch has no metal part exposed in air.
4、Light should not be installed over HV&LV power distribution equipments and screw wire in substation.
5、Base and support of spot light should be fixed strongly. King journal should be screwed up and fixed in ray axis direction.
6、Exterior wall fitting should be provided water discharging hole. Water proof device should be provided to insulation table and wall.
u Special light installation 专用灯具安装：
Light installation should comply to following requirements:
（1）、Besides normal power, another spare power or power produced by diesel oil generator or accumulator will be provided to emergency light. Emergency light with its own power is another choice.
（2）、Escape lighting consists of exit light and escape legend. Height of exit light is no less than 2m and should be installed at escaping exit and upper parts of staircase.
（3）、Escape legend should be installed on the top of safe exit and within 1m on the wall of staircase, escaping corridor and corner. It can be installed on the upper part when the place is not easy to install. Distance between escape legend over escape corridor should be no more than 20m (distance in civil defence should be no more than 10m)
（4）、Position of escape legend should assure passing smoothly and will not be confused by other marks.
（5）、Separate emergency light circuit should exist in emergency light wiring. Wire pass through different fire prevent areas should be provided fire prevention mesure.
（6）、Fire-resisting wire, cable will be used as escaping light wiring. Wire will thread surface conduit or recessed rigid conduit inside inflammable material. Thickness of protection layer should be no more than 30mm. Copper core insulated wire with rate voltage no less than 750V will be used.
u Power on and test run of lighting 照明通电试运行：
1、Control of lighting circuit should be same as marks of lighting power DB when lighting system is power on. Switch should match sequence of lighting fixture control. Direction turn and speed regulating switch of fan should work well.
2、Power should be 24h supplied to lighting system of public building and 8h supplied to civil building. All light fitting should be power on and record should be taken every 2h. There should be no faults in continuous running.
u Installation of switches and sockets 开关、插座安装
一、Wiring of socket should comply to following regulations插座接线应符合下列规范：
1、Left pole and upper pole of single phase 2 pole socket should connect to phase line and right pole and under pole should connect to neutral; right pole of single phase 3 pole socket should connect to phase line and left pole should connect to neutral line.
2、PE or PEN line should connect to upper pole of single phase 3 pole socket, 3 phase 4 pole socket and 3 phase 6 pole socket. Earthing connector of socket will not connect to neutral connector. 3 phase socket at the same place connect wires in same way.
3、PE or PEN line is not allowed to connect in series between sockets.
4、Recessed socket panel stick to wall tightly without gap around it. Surface of it is smooth, no cracks, scratched and with all decorated bolt.
5、Floor socket panel is parallel to floor or stick to floor tightly. Cover is fixed tightly and sealed.
6、Height of sockets in same room should be same.
二、Installation of lighting switches should comply to following regulations照明开关安装应符合下列规定：
（1）、Switches in one building should choose one series of products. Switches in good condition should be same and control easily.
（2）、Location of switches should be easy to use. Edge of switch should be 0.15~0.2m away from door frame and 1.3m away from floor. Ceiling switch should be 2~3m from floor, however, when the height of room is less than 3m, ceiling switch should be away from ceiling no less than 100mm and the switch should be downward vertically.
（3）、Switches of same type should be installed together and height should be same in one room. Control of switch should be in order. Ceiling switch of parallel installation should be more than 20mm away from each other.
（4）Recessed socket panel stick to wall tightly without gap around it. Surface of it is smooth, no cracks, scratched and with all decorated bolt.
u Indoor water supply system 室内给水系统
Ø Pipes connecting water tank in basement and connecting pumps and water tank on roof are composite metal plastic pipes and threaded connection. Other pipes are PP-R pipe and pipe fittings with thermal connection. PP-R pipe and pipe fitting should be 2.0MPa pipes.
Ø Interior water supply valve whose DN>50 should be butterfly valve or gate valve. Valve whose P=1.0MPa and DN≤50 should be ball valve.
Ø Pipes in outdoor ceiling should be polyurethane flexible pipe insulated by aluminum foil. Thickness of insulated layer: when DN>50, it should be 40mm; when DN≤50, it should be 30mm. Details refer to O3S401 and 87S159.
Ø Test pressure of domestic water supply should be 1.1MPa; Water supply for fire fighting should be 1.2MPa.
Ø Fire hydrant system and sprinkling system should be connected by galvanized steel pipe of threaded connection. Slope of transverse sprinkling pipe should be 0.2%, and pipe should be water release riser. Sprinkler head should be connected by DN25. Pressure gauge will be put in front of water release valve. Installation of wet-test alarm valve refers to collective drawings 89SS175 of national standard 89SS175.
Ø Installation of valve should comply to item 3.2.4 and 3.2.5 in GB50242-2002.
Ø Installation of water supply pipe should comply to item 4.1.3；4.1.7；4.1.8；4.2.2；4.2.6；4.2.7 in GB50242-2002.
Ø Installation of indoor fire hydrant should comply to item 4.3.1；4.3.2；4.3.3 in GB50242-2002.
Ø Installation of connector of pipes should comply to item 3.3.15 in GB50242-2002.
Ø Installation of hanging support of pipes should comply to item 3.3.7；3.3.8 in GB50242-2002.
Ø Installation of water supply pipe and fittings should comply to item 4.2.1；4.2.2；4.2.3；4.2.4；4.2.5；4.2.6 in GB50242-2002.
u Indoor water drainage system 室内排水系统
Ø Water drainage system should be connected by PVC-U pipes and pipe fittings in adhesives way. Down pipe which is used PVC-U down pipe and fitting should be connected by rubber ring of R-R pipe socket. Water drainage riser should be connected with water drainage pipe by 2 elbows of 45°.
Ø Watering test should be done before water drainage pipe is embedded. Height of water should be not lower than upper edge of 1F sanitary or height of floor. Checking method: after water surface falls down after 15min of full water, fill up water again and observe it for 5min, if water surface does not fall not, no leakage of pipe and joint will be accepted.
Ø Slope of plastic transverse pipe for domestic waster water.
Min Slope 最小坡度（‰）
Ø Expansion joint should be installed on plastic water drainage pipe according to design brief and its position. Expansion joints with interval no more than 4M will be provided with fire protection zone or fireproof covers Interval between should be no more than 4M.
Ø Main water drainage riser and level pipe should be provided through ball test. Diameter of ball should not be 2/3 times less than pipe diameter. And rate of through ball should be 100%.
Ø Check point should be set on water drainage riser each level. It should be set at lowest level and highest level which has sanitary fittings. Center of check point should be 1M above floor with error of +20mm. Direction of check point should easy for repair. Manhole should be installed at the check point when recessed riser is installed. Cleanout should be installed no less than 200mm away from wall. If cleanout is replaced by choke plug at start point of waster water pipe, it should be no less than 400mm away from wall.
排水立管上应每隔一层设置一个检查口，但在最低层和有卫生器具的最高层必须设置。检查口中心 高度距操作地面为1M，允许偏差+20mm，检查口的朝向应便于检修，暗装立管时在检查口处安装检修门。清扫口的安装与墙面距离不得小于200mm，若污 水管起点设置堵头代替清扫口时，与墙面距离不少于400mm。
Ø Water drainage aeration pipe should be 300mm higher than roof and it should be thicker than maximum of snow thickness.
Ø Hanging hook and bar clap on metal pipe should be fixed on load-carrying member. Fixed interval: transverse pipe should be shorter than 2M, riser should be no longer than 3M. When the height of storey is not higher than 4M, Fixed parts can be installed on riser. Abut or fixed fittings should be provided to angle branch on bottom of riser.
Ø Max interval between support of plastic pipes: unit: M
Caliber 管径（mm） 50 75 110 160
Riser 立管 1.2 1.5 2.0 2.0
Transverse pipe横管 0.5 0.75 1.1 1.6