1. Construction unit qualification and construction personnel qualification certificate 1.1 Common problems are not handled according to the construction procedures. There is no construction project contracting project whose qualification or qualification level does not meet the requirements. The construction personnel do not have the required qualification certificates and employment certificates, resulting in the installation project not reaching The requirements for the specified indicators. 1.2 Construction points The electrical installation project is a highly specialized type of work, requiring the construction unit to have a qualification certificate recognized by the local power supply department before construction. The construction department shall assist Party A and the general contractor to carefully review the qualifications of the subcontracting unit, propose review opinions, and select the construction unit in accordance with the principle of fair competition. Relevant on-site construction personnel should also check their qualification certificates and employment certificates one by one to ensure that they are certified to work and ensure the quality of installation. 2, electrical main equipment and materials 2.1 common problems 1) no product certification, production licenses, technical specifications and inspection reports and other documents; 2) wire resistivity, melting point, mechanical properties, cross-section values, insulation values, temperature coefficients, etc. The performance index does not meet the requirements; 3) The cable insulation resistance is small, the corrosion resistance is poor, the pressure and temperature resistance are low, the insulation layer and the core are poorly rigorous; 4) the power and lighting distribution box and the socket are poor in appearance, and the geometric size is not To the requirements, the thickness of the steel plate and plastic casing is not enough, which affects the strength of the box and the corrosion resistance does not meet the requirements; 5) The conductivity value of the switch and socket does not match the nominal value, the conductive metal sheet is not strong, the contact is not good, and it is easy to generate heat. Failure to meet safety requirements, plastic products have low flame retardancy, temperature resistance and poor safety performance; 6) poor quality of lamps and light sources, poor mechanical strength, poor waterproof and anti-corrosion performance, and short service life; 7) various wire and tube walls are thin, The strength is poor, the quality of the galvanized layer of the galvanized pipe is not satisfactory, and the folding resistance is poor. 2.2 Construction points 2.2.1 Strict implementation of witness sampling, supervision and sampling system Implementation of building electrical engineering main materials (PVC wire trough, wire and tube, wire and cable, leakage switch, air switch) witness sampling, supervision and sampling system, requiring construction companies to cooperate with local quality The supervisory department shall do the witness sampling and supervision of the on-site inspection, and the construction engineer shall be certified to perform and cooperate. 2.2.2 Making electrical equipment materials into the field After the electrical equipment and materials enter the construction site, the construction engineer should check whether the freight yard meets the requirements of the specification, check whether the parameters, specifications, performance and other parameters of the equipment and materials are consistent with the design. Certificates, spare parts, and visual inspections, make out of the box, and keep them in a safe place. 2.2.3 For the supervision and sampling, materials that do not meet the design requirements of Party A are forbidden to use. 3. Lightning protection grounding and equipotential bonding 3.1 Common problems 1) Rebar with rebar, inter-belt and down-conductor with butt welding, single-sided The welding or lap length is not enough, and the weld is rusted obviously; 2) the slag, the welding slag, the welding, the bite, the weld is not full, and the welding slag is not knocked off. And other defects; 3) The lightning protection belt is seriously deformed, the bracket is detached, the distance between the lower points is too large, and the wiring outside the line is not reserved; 4) The roof metal objects (pipes, ladders, flagpoles, equipment casings, etc.) are not related to the lightning protection system. Connected; 5) Replace PE wire and equipotential bonding with metal pipe, insufficient diameter of bridge and metal pipe, electrical cabinet, box, door, etc.; 6) When multi-storey residential building adopts TN-S system, incoming line is in total There is no repeated grounding at the meter box, and the MEB is not made in the power distribution room as required. 7) The “grounding bar†of the device is not directly connected to the grounding trunk, but through the transition of the bracket and the base channel, connecting different metal grounding wires. Consider the effects of galvanic corrosion; 8) Socket grounding wires are stringed together Connected, fixtures with a height of less than 2.4m can be placed close to the ungrounded metal conductor. 3.2 Construction points 1) The lightning protection belt should be lap welded, the lap length should be greater than 10d, double-sided welding should be used and the welding should be anti-corrosion, and the rebar should not be used instead of round steel to make lap joint; 2) lap welding The seam should be full, smooth and even (especially opposite welding, overhead welding), timely knock out the welding slag, timely repair welding unqualified welds; 3) the distance between the lightning protection brackets is not more than 1 ~ 1.5m, the buried depth should be greater than 10cm The distance between the first, second and third lightning protection points shall be less than 18m, 20m and 25m respectively, and a D12mm or 40×4mm galvanized conductor shall be welded at the lower part of the lower line at 0.8m below the outdoor floor, and The distance from the outdoor wall shall not be less than 1m; 4) the roof metal shall be connected to the down conductor; 5) the equipotential bonding branch shall not be less than 6mm2 copper conductor, bridge and metal pipe, live cabinet door or box door, etc. The copper wire with a cross-sectional area of ​​not less than 4mm2 is required for the wire; 6) The PE wire of the TN～S system should be grounded repeatedly at the meter box, and the high-rise and small high-rises should be used as the MEB in the power distribution room; 7) Equipment (power cabinet The "ground row" of generators, pumps, etc. must be directly connected to the grounding trunk, and the base channel should be cross- Grounding and grounding mark. Where there is vibration, the grounding bar should have anti-loose measures. Before construction, the influence of galvanic corrosion should be considered and connected by suitable materials. 8) The grounding wire of the socket should be welded or “T†before being connected to the socket terminal. Connect to avoid grounding failure of the subsequent socket due to loose terminals; the bare conductors of the luminaires below 2.4m should have dedicated grounding bolts and markings and must be grounded reliably. 4, wire and tube laying 4.1 common problems 1) replace the thick-walled pipe with a thin-walled pipe, black iron pipe instead of galvanized pipe, PVC pipe instead of metal pipe; 2) the bending radius of the threading pipe is too small, and there are bends, wrinkles, In case of seriousness, "dead bend" occurs. When the pipe is too long or turns, the transition box is not set as required. 3) The cable tubes are overlapped in multiple layers, and the electric wires are tightly attached to the row, which affects the civil construction, and the buried wall and buried depth of the pipe are not enough; 4 The wire tube enters the distribution box is not smooth, the length of the outcrop is not suitable, the nozzle is not flat, no protection ring is used, and it is not locked and fixed; 5) the metal pipe thread connection and the intermediate junction box do not cross the steel bar, not grounded Or the grounding is not strong; 6) When the PVC wire tube is pre-embedded, use a plastic clamp to flatten and bend the pipe mouth. 4.2 Construction points 1) Strict requirements According to the design and specifications of the piping, the professional engineers must strictly control the construction, the pipe does not meet the requirements, construction is not allowed. When the PVC wire and pipe is pre-buried, the wall thickness requirement is not less than 1.8mm; 2) The following requirements are required to check the bending radius of the conduit: n When the piping has only one 90 о bend, the bending radius should be ≥ 4 times the outer diameter of the tube; n for two or three 90 о bends, the bending radius should be ≥ 6 times the outer diameter of the tube; n dark The bending radius of the pipe shall be ≥ 6 times the outer diameter of the pipe; n the bending radius of the pipe buried in the ground and concrete shall be ≥ 10 times the outer diameter of the pipe; the pipe shall be in the appropriate position plus the transition box if the pipe exceeds the following length: n straight line 50 m; n 30 m, No bending; n 20m, a 90о bend; n 15m, two 90о bends; n 8m, three 90s bends. 3) Wire and pipe laying should be avoided as much as possible to overlap and cross. It should not be placed side by side. It should be placed at intervals. The pipe should enter the wall or the ground. The outer surface of the pipe should be ≥20mm from the wall surface and the ground. The pipe laying requirements should be “horizontal and verticalâ€. Straight"; 4) The wire tube should be leveled into the distribution box, the length should be 3 ~ 5mm, the pipe mouth should be sheathed and locked, enter the wire tube of the floor-type distribution box, the pipe mouth should be high The base surface of the electric box is 50~80mm; 5) The joint of the steel pipe and the intermediate junction box should be connected by a special grounding card. The pipe must be reliably grounded according to the specifications. The special grounding card for the galvanized pipe entering the distribution box and ≥2.5mm The two-color BV wire is firmly connected to the box body. The pipe with diameter ≥40mm can be fixed to the box by spot welding and brushed with anti-rust paint. 6) When pre-embedded PVC wire tube, it is forbidden to use rubber clamp The nozzle is flat, and the PVC plug with the diameter of the pipe is used to cover the nozzle, and the tape is tied tightly. 5, the entrance line pipe pre-buried 5.1 common problems 1) the use of thin-walled steel pipe instead of thick-walled steel pipe; 2) the pre-buried position deviation is large, the depth does not meet the requirements; 3) the inlet pipe and the underground outdoor wall are not well waterproofed; 4) The corner is welded with electric welding, and the upper wall pipe is welded to the horizontal inlet pipe network to form a 90 о angle. 5.2 Construction requirements 1) Thickened steel pipes or PVC pipes that meet the requirements must be used for the pre-embedded pipes (generally, the wall thickness of pipes above Φ14 is 4.5mm or more, and the thickness of Φ56 or more is more than 3mm); 2) Strengthening with civil engineering and other professions Coordination work, clear the outdoor floor elevation, buried pipe position, to ensure that the buried pipe depth is not less than 0.7m; 3) to do the waterproof work after the buried pipe, generally required due to professional waterproof construction team to do waterproof treatment ; 4) The elbow of the upper wall of the pre-buried steel pipe must be bent with a bender, and no welding or welding is allowed. The steel pipe should not have cracks and significant dents after bending, and the bending radius should not be smaller than the pipe. 10 times the outer diameter, and should not be less than the minimum allowable bending radius of the cable that is threaded. 6. Wire threading, connection, dressing, color standard, etc. 6.1 Common problems 1) Wire bending and twisting into the line pipe, wiring in the pipe and in the wire slot; 2) The wire is not arranged neatly, loosely, without bandage and bundle, and the wire head is bare; 3) Multiple single wires are pressed together, and multiple strands do not need copper joints, no tin, less bolts, springs, etc.; 4) Phase lines and N-line and PE lines are unclear and confused. 6.2 Construction points 1) Before the wire is piped, check the “nano†and protective sleeves of the nozzle, and whether there are any debris in the pipe. If it is necessary, remove it first. The pipe and the wire slot are forbidden. 2) The wire layout should be horizontal and vertical. The length of the wire ends shall be the same. There shall be no bare conductors after the terminals are inserted. The joints of the copper joints and the wires shall be tightly wrapped with insulating tape of the same color as the wires; 3) the connecting wires on each terminal and terminal shall not exceed 2, and need to add a flat washer in the middle, do not allow more than 3 connections; 4) The connection of multiple strands of wire, crimped with galvanized copper joints, the bare conductor should be tinned, and the wire of the tin must be removed Clean, prevent wire oxidation; 5) The color line of phase line and N line and PE line should be clearly distinguished, not only L1 phase - yellow, L2 phase - green, L3 phase - red, N line with light blue or blue, PE Lines must use yellow-green two-color wires, and red should generally be used for single-phase. 7. Wiring and installation of distribution box 7.1 Frequently Asked Questions 1) The power distribution box is not set according to the drawings, the coordinate offset is obvious, the box is not straight; 2) The box is not fixed firmly, and there is mortar and debris in the box. 3) The casing opening does not meet the requirements, destroying the paint protection layer, the box is not rust-proof and anti-corrosion treatment; 4) The floor power box is not grounded, the cross-section of the grounding conductor is not enough, the wire is bare, the wiring is not neat, the wire Do not leave a margin. 7.2 Construction points 1) The distribution box shall be set according to the requirements of the drawings. The left and right sides of the box shall have a deviation of ≤50mm, and the height shall be as indicated in the drawings. If not stated, the general occasion shall not be less than 1.3m, nursery school, residential and elementary school. Not less than 1.8m; 2) After the template is removed, it is necessary to clean the debris and rust spots in the box in time, brush the anti-rust and anti-corrosion paint, and fix and seal the box when it is pre-embedded; 3) the opening and the entrance of the box When the box does not match, it must be mechanically opened or re-processed by the manufacturer, and the anti-corrosion treatment must be done. 4) The grounding point and wire of the box of the power box must be exposed, and the bottom of the box should not be welded. When the phase line cross section S≤16 mm2, the minimum cross section of the grounding wire is S. When 16 < S≤35 mm2, the minimum cross section of the grounding wire is 16 mm2. When S > 35 mm2, the minimum cross section of the grounding wire is S/2. 5) The wire inside the box should not be exposed, the wiring should be neat and beautiful, the binding should be fixed, and the wire should have a certain margin, generally requiring 10~15cm. 8, open tube, socket bottom box, panel installation wiring 8.1 common problems 1) line box pre-buried too deep, the height is not the same, the panel and the wall have gaps, paint, not straight; 2) switch, socket phase Line, neutral, and PE wires are connected in series; 3) The wire ends of the switches and sockets are bare, the bolts are loose, the wire is insufficient, and there are debris in the box. 8.2 Construction points 1) When installing the panel, it should be horizontal and vertical, and the level should be adjusted to ensure the uniform installation height. When the cable box is buried too deep, the wire box should be installed. After installing the panel, it should be full and fill, not allowed to stay. Gap, in addition to do a good job of cleaning and protection; 2) Strengthen the supervision work to ensure that the phase line, neutral line and PE line in the switch and socket are not connected in series; 3) remove the debris in the box and the thread before installation. To be neat and not exposed, the single core wire should be twisted into double strands when inserting the wire hole, and tightened with screws to ensure that the wire is firmly pressed. 4) The wires in the switch and socket should have a certain margin, generally 100~ 150mm is suitable. 9. Installation of lamps and ceiling fans 9.1 Common problems 1) The installation of lamps is biased, the horizontality and straightness deviation of the rows of lamps exceed the specified value; 2) The ceiling lamps directly mounted on the top plate are not equipped with wooden tables or wooden tables with poor quality. The ceiling lamp is not fixed on the ceiling plate by the fixing frame, but is fixed directly by the self-tapping screw. The opening of the downlight mounted on the ceiling of the ceiling is too large and untidy; 3) The chain of the hanging chain fluorescent lamp is not parallel, and the wire hanger is led down. The chain is not bifurcated; 4) The ceiling fan hook is processed with rebar, and the distance between the ceiling and the junction box is too large to expose the wire, or the hook is directly fixed on the keel; 5) the balcony lamp chassis is rusted and dropped; 6) The grounded luminaire cover is not grounded. 9.2 Construction points 1) When the lamps, switches, sockets and ceiling fan hooks are buried, they should meet the requirements of the drawings. When positioning, the left and right sides of the box are ≤50mm, and the lamps arranged in the same room are arranged in rows. The center is full of deviation ≤5mm The switch box is generally 150-200mm from the door frame; 2) the ceiling lamp is to be fixed to the ceiling plate by a fixed frame (good-quality wooden table), but can not be directly fixed with self-tapping screws, and the opening of the ceiling of the ceiling should be fixed first. Coordinates, ensure straight, neat, even interval, etc., the size of the opening should meet the specifications of the downlight; 3) The chain of the hanging chain fluorescent lamp should be parallel to each other, no splayed type, the wire should be led together with the chain 4) When the ceiling fan hook is buried, the rebar is not allowed. The galvanized round steel not less than Φ8 is fixed with the steel bar in the plate. The bell of the ceiling fan should be able to ceiling and cover the hook and the junction box. 5) The thickness of the bottom plate of the luminaire of the balcony should be ≥0.5mm, and the surface of the paint should be even and smooth, which can prevent rust. The glass cover should not be too thin to avoid rupture during installation. 6) Large luminaires must be fixed or pre-installed. Buried hook, outside 10, cable, busbar installation 10.1 common problems 1) cable laying mess, no signs after installation; 2) in the shaft, the cable hole is not tightly sealed, the equipment installation location is not reasonable, resulting in operational difficulties; 3) cable bracket, The bridge is not reliably grounded, the cable is not fixed, the filling rate is too large, and the bending radius is insufficient. 4) The cable terminal is not processed, and it is not tightly sealed after passing through the household pipe; 5) The connector is pressed with the non-standard terminal, resulting in the connector. Broken; 6) The busbar's plug-in box is not installed straight. 10.2 Construction points 1) During construction, the size cables should be arranged in the direction and position. After installation, the moisture-proof and anti-corrosion cards should be listed in the same way. The number, model, specification and starting point of the cable should be indicated on the card. The listing position is: cable Terminal heads, corners, interlayers, ends of shafts, manholes in cable trenches, straight lines every 50m, etc.; 2) Use a mixture of hemp and asphalt to block the hole through which the shaft cable passes to prevent the “chimney effectâ€. After the cable passes through the household pipe, it should be tightly sealed and plugged into the basement to be waterproofed. 3) The filling rate of the cable in the bridge should not exceed 40% (control cable is not more than 50%). When the cable is laid vertically, the upper end and each It should be fixed at 1.5~2m apart. When laying horizontally, it should be fixed at the first and last ends, turning and every 5~10m. The galvanized cable tray must have not less than two connecting fixing bolts with anti-loose nuts or anti-loose washers. The length should be less than the length that can be connected to the grounding trunk; 4) Cable fixing brackets, grounding terminals and other materials should be used according to the specifications. The corresponding hydraulic clamps and kits should also be accurately selected during construction; 5) Cable terminals head Should be handled, when installing the plug-in box, it should be horizontal and vertical, and the contact with the busbar is reliable and firm. 11. Cable trench structure and cable pipe laying 11.1 Frequently Asked Questions 1) The buried cable pipe is not buried enough, the bell mouth is broken and not standardized; 2) The cable trench and concrete bracket are not straight and easy to break; 3) Cable trench and cable duct Drainage is not smooth; 4) Steel pipe anti-rust and anti-corrosion paint is uneven, sealing is not enough, especially the anti-rust and anti-corrosion work in the pipe; 5) The grounding pole is not straight and loose in the cable trench, and the welding with the pipe is not Comprehensive, partial leakage welding. 11.2 Construction points 1) When the cable tube is pre-buried, the depth should be less than 0.7m. If the objective conditions are not allowed, the cement mortar should be sealed on the tube to ensure that the pipe is not crushed; the bell mouth is required to be even and neat, no Crack; 2) When installing the concrete bracket, the cable should be leveled and vertical, and the distance between the uppermost bracket and the top of the trench is 150-200mm, and the distance from the lowest bracket to the bottom of the trench is 50-100mm; qualified concrete brackets should be used to ensure that there is Sufficient supporting force, steel brackets should be rust-proof and anti-corrosion guarantee; 3) The slope of the drainage ditch at the bottom of the cable trench should not exceed 0.5%, and the water collecting pit should be set, and the accumulated water should be directly discharged into the sewer; 4) The cable pipe should be thick Wall steel pipe, both inside and outside should be brushed with anti-rust anti-corrosive paint or asphalt, the paint surface should be even, especially at the welding port, it needs to be rust-proof; when the two cable pipes are butted, the inner pipe should be aligned, then add a short casing ( The length is not more than 2.2 times the outer diameter of the cable tube. The welding is firm and sealed. 5) The grounding flat steel in the cable trench should be firmly installed. Generally, a fixed terminal is installed every 0.5~1.5m, which is 250~ higher than the bottom height of the groove. 300mm, passing 12. Installation of outdoor lamps (street lights, lawn lights, garden lights, etc.) 12.1 Frequently Asked Questions 1) Light poles are loose, rusted, and paint is off; 2) Outdoor lamps are not grounded or grounded installation is not satisfactory; 3) Lampshades are too thin and easy Broken or detached; 4) The wattage of the lamp of the lawn lamp and the floor lamp is too large. When the lampshade is used, the temperature of the lampshade is too high, and it is easy to burn people or the corner of the lampshade is sharp and easy to cut people. 12.2 Construction points 1) Select qualified lamps. For coastal humid cities, it is necessary to use better anti-rust lamp poles. The lampshades should have strong resistance to typhoon; 2) Street lamps, lawn lamps, garden lamps and floor lamps must Good grounding, the grounding pole of the pole must be welded firmly, the joint is tinned, the PE protection line of the streetlight power supply must be connected with the spring washer after the PE protection line is connected with the grounding pole of the lamp pole; 3) 60W bulb surface The temperature can reach 137 ~ 180 ° C, 100W can reach 170 ~ 216 ° C, so when using the light bulb of the ground lamp, lawn lamp, if the bulb of 60W or more is installed, it is easy to make the temperature of the protective cover too high and burn people; The corners should not be too sharp to avoid cutting people. 13. Installation of weak current system 13.1 Frequently Asked Questions 1) The wires in the weak electric shaft are disorderly, not bundled and fixed; the filling rate of the slot is too large; 2) the number of the line of the DP line is not obvious, the font of the numbered card is ambiguous; 3) TV The shielding layer of the antenna is damaged, the TV audio and video is distorted; 4) the telephone socket is loose, the telephone sound quality is distorted; 5) the fire probe is too close to the luminaire, and the heat emitted by the luminaire affects the sensitivity of the probe. 13.2 Construction points 1) When multiple wires are laid in the shaft, bundle them into bundles, fix them in the trough every 1.5m, cover the trough plate, and fill the groove with no more than 50%; 2) DP The telephone line in the box should be neatly arranged. The line head of each telephone line should be marked with a moisture-proof card to indicate the circuit number and the room number. 3) The TV antenna should be smoothed before the pipe is worn, and the pipe should be cleaned. Carefully pull to avoid damage to the shielding layer and affect the clarity of the TV image and sound quality. 4) The telephone line connector should be connected with moisture-proof wiring, crimped with wire clamp, and the telephone socket should be crimped with RJ11 telephone crystal head. In-line telephone socket wiring should be carefully tightened, not only to tighten the wire but also to break the wire; 5) In order to ensure the sensitivity of the fire-fighting probe, the distance between the center point of the lamp and the probe must be no less than 50cm.
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