What are the basic knowledge of hydropower embedment in construction site?

On-site water and electricity embedding is a knowledge that many workers will want to master, so do you know how to implement on-site water and electricity embedding? The following carefully recommended the basic knowledge of water and electricity embedment in the construction site for you, hoping to help you.

Basic knowledge of water and electricity embedment in construction site I. Material aspects

Hydropower installation materials are divided into main materials and auxiliary materials, and the supply methods are Party A, Party A, Party B and Party B; The materials supplied by Party A are generally: wires, cables, PVC electrical bushings and accessories, bridges, distribution boxes, water supply pipes and accessories, drainage pipes and accessories, submersible pumps, valves, etc. Materials supplied by Party A and Party B generally include: switches, sockets, lamps, steel-plastic pipes, galvanized steel pipes and fittings, welded steel pipes and fittings; Most of the materials supplied by Party B are auxiliary materials.

Material control should pay attention to the following aspects:

1, before the materials arrive.

(1) Understand the cycle from ordering to delivery of various materials supplied by Party A. According to the workflow, materials supplied by Party A generally need to be declared in declare in advance one month in advance, and others need to be declared at least 10 days in advance;

(2) Before making the application form for materials supplied by Party A and the supply notice, you must make a team material application form for the team to sign, so as to avoid subsequent disputes; At the same time, check the quantity of materials, and check whether the specifications and models of materials are consistent with the blueprint. Remember not to use electronic drawings to check materials, because electronic drawings may be partially different from blueprints;

(3) When making the application form and supply notice of materials supplied by Party A, be sure to check whether the date, supplier name, construction unit name, material name, specification, model, quantity and other information are correct;

(4) Before the arrival of the goods, the conduit where the telephone is really exposed should be slotted and concealed;

(3) Other precautions:

(1) The welding of grounding body and grounding trunk line shall be completed before concrete pouring;

(2) pay attention to the direction of the evacuation indicator light in the hidden column, that is, which side of the hidden column;

(3) The civil air defense drainage pipe of the basement floor and the drainage pipe of the elevator foundation pit are mostly galvanized steel pipes, and galvanized steel pipes shall not be welded;

(4) Submerged sewage pump pipes must be embedded in the bottom plate. If they are hidden in the leveling layer of the bottom plate, the cover plate of the sump may not be installed;

2, the basement roof embedded

(1) Work contents: welding of grounding trunk lines, embedding of power supply lines and pipes for power and lighting, embedding of fire-fighting and weak current lines, embedding of water supply pipe sleeves, fire-fighting sleeves and civil air defense sleeves;

(2) Common problems and solutions:

① Problem: Because there are many embedded pipes in the basement roof, it is easy to miss or cause embedded errors;

Solution: Check on the spot when embedding;

(3) Other precautions:

(1) waterproof casing is used for the embedded casing of the basement roof;

(2) When the basement roof is embedded, the JDG pipe should be retained and fixed with set screws;

(3) When pouring concrete, someone must protect the pipeline;

3, the main embedded stage

(1) Work content:

① Embedded high-voltage system: indoor switches, sockets, lamps and distribution boxes, well switches, sockets, lamps and cable sleeves, roof switches, sockets, lamps and cable sleeves;

② Embedded water supply and drainage system: embedded indoor drainage sleeve, water supply pipe sleeve and water supply and drainage sleeve of water well;

③ Pre-embedding of fire fighting system: pre-embedding of water well fire fighting riser and spray riser sleeve, pre-embedding of spray branch pipe, pre-embedding of smoke sensor, fire hydrant button, manual alarm button, audible and visual alarm, door closer, floor lamp, positive pressure air supply valve, etc.

④ The embedded contents of weak current system include: visual intercom embedded indoor extension, gas leak detector, door magnet and emergency button;

⑤ Buried lightning protection: buried grounding trunk line, buried lightning protection detection point, buried equipotential welding in toilet, buried equalizing ring, buried downlead and buried equipotential in roof elevator room;

(2) Common problems and solutions:

1) Frequently asked questions about embedded power sockets

① Problem: The pipes overlap, that is, it is easy to occur in household distribution boxes, places where multi-media coexist and pipes are dense. Three PVC pipes overlap at the same point, resulting in insufficient protection thickness and affecting the structure;

Solution: Follow-up inspection shall be carried out during pre-embedding, and on-site rectification shall be carried out at the overlapping places of pipelines;

② Problem: Parallel pipes are easy to have multiple PVC pipes juxtaposed in household distribution boxes, multi-media places and dense pipelines, which will not affect the pouring of concrete and the quality of the slab, resulting in water leakage in the later stage; So keep a certain distance.

Solution: Follow-up inspection shall be carried out during pre-embedding, and on-site rectification shall be carried out at the overlapping places of pipelines;

③ Problem: At the distribution box, the position of drilling holes on the formwork shifted due to the formwork moving or using the old formwork, so that there were too many holes on the formwork of the beam that were not blocked, which affected the pouring quality of the beam.

Solution: If the original hole is not used, the team should be required to block it; If there are any holes, you should contact the carpentry team to replace the template;

④ Problem: At the distribution box, the conduit is concentrated in the local part of the beam, which affects the effective section of the beam. It is required to set it separately and keep a certain distance.

Solution: fully explain the problem to the team before construction, and pay special attention to inspection when embedding;

⑤ Problem: When the time is short, the upturned PVC pipe will not be bound and fixed, and it is easy to be poured into the board and blocked.

Solution: fully disclose to the team before construction, and check the embedment before concrete pouring;

2) Frequently asked questions about lighting embedding.

① Question: The indoor lighting head box is offset, and whether the number of embedded boxes of lamp heads on the roof (especially the inclined roof) is correct;

Solution: fully disclose to the team before construction, and check the embedment before concrete pouring;

② Problem: There is no embedded pipe between the waterproof ceiling lamp in the bathroom and the equipotential terminal board LEB.

Solution: fully disclose to the team before construction, and check the embedment before concrete pouring;

③ Problem: It is forbidden to butt weld metal conduit; Galvanizing and wall thickness are less than the arrival time and unloading place, so as to avoid arrival after work;

(5) Print a supply notice to facilitate on-site verification whether the materials present are consistent with the currency notice;

2. When the materials arrive

(1) After the materials arrive at the unloading place, check whether the material acceptance sheet is consistent with the supply notice, check whether the certificate of approval and test report are complete, and then notify Party A and the supervisor for acceptance;

(2) After acceptance, notify the team to unload the goods, check the materials on site and hand them over to the team for use. During unloading, it is necessary to check whether the material is damaged, missing components, scratched, etc.

(3) Check the number of material accessories (such as screws, bridge cover, etc.). ) avoid not memorizing enough. If assembly is required, check whether the specifications are consistent;

(4) After the quantity is confirmed, it will be handed over to the team for use and signed by the team for confirmation;

3. After the materials are signed.

(1) When signing the material acceptance sheet, check the following information of the material acceptance sheet:

The information on the material acceptance list should be carefully confirmed and checked, including the plot, building number, date, etc.

Check whether the supplier signs and the date is the same day, and check whether the handwriting of the acceptance form is clear;

When the materials are accepted, the name, specification, model, quantity and use position of the materials must be correct;

(2) After signing the material acceptance sheet, make a material distribution sheet for the team to sign, and ensure that the attachment of the material is clearly indicated on the distribution sheet to avoid disputes.

(3) Supervise the team to take good care of the materials, do not pile them up at will, and do not expose some materials to the sun;

Second, the embedded construction

1, the basement floor is embedded.

(1) Work contents: welding of grounding body and grounding trunk line, embedding of evacuation indicator pipe, embedding of drainage pipe, embedding of civil air defense pipe, embedding of power supply pipe of submersible sewage pump and embedding of water outlet pipe of submersible sewage pump;

(2) Common problems and solutions:

1) Welding of grounding body and grounding trunk line:

① Problem: The two steel bars of the grounding body are not welded to the two inclined steel bars of the pile foundation (mostly jumpers) or are not connected to the down lead;

Solution: Follow-up inspection shall be carried out after the grounding body is welded, and the nonconformities shall be rectified on site;

② Problems: During the welding process, the lap length does not meet the requirements, or the welding is not full, virtual welding, welding slag is not removed, etc. According to Code for Acceptance of Construction Quality of Building Electrical Engineering 24.2. 1, the grounding device is welded by lap welding, and the lap length shall meet the following requirements: the lap length of flat steel is twice the width of flat steel, and it is welded on at least three sides; The lap joint between round steel and round steel is 6 times the diameter of round steel, and both sides are welded; The lap joint between round steel and flat steel is 6 times the diameter of round steel, and it is welded on both sides; Flat steel and steel pipe, flat steel and angle steel are welded, close to the outer sides of angle steel, or close to the surface of 3/4 steel pipe, and welded on the upper and lower sides; In addition to the welded joints buried in concrete, there are also anti-corrosion measures.

Solution: Make disclosure to workers before welding, and conduct follow-up inspection when welding grounding body;

2) Embedded evacuation indicator tube:

① Problem: After pouring the basement floor, the JDG conduit at the column position is exposed;

Solution: When embedding, it is required to embed JDG pipes under gluten; For steel conduit less than 2mm, welding of casing is not allowed. JDG pipes in public areas shall not be welded.

Solution: make full disclosure to the team before construction, and supervise the construction technology of JDG during construction;

3) Common problems of lightning protection and grounding embedding

① Problem: The cross-sectional area of steel bar leading to LEB box should not be too small, not less than 25*4 flat steel or12mm round steel.

Solution: fully disclose to the team before construction, and check the embedment before concrete pouring;

② Problem: The rebar led to LEB box cannot be spot-welded on two different rebar.

③ Problem: If the steel bars leading to the LEB box are welded from the beam, the steel bars of the beam must be welded with the steel mesh.

Solution: make full disclosure to the team before construction, and inspect the steel mesh during welding;

(3) Other precautions:

(1) The gluten is not tied completely when the electrical embedded steel bar is tied at the bottom;

② The upturned part of the PVC embedded pipe of the power socket should be embedded in the beam or shear wall as much as possible, so that it is not easy to block the pipe due to being stepped on;

(3) The pipes in the shear wall can be embedded to the height of the socket at one time, so that there is one less joint.

(4) When the socket in the shear wall is embedded, the leveling layer height of 3~5cm should be considered;

⑤ When embedding, the position of socket and light box can be released in advance when the formwork installation is completed and the bottom reinforcement is not bound, which can improve the embedding speed and know the embedding direction after pouring.

⑥ The leads from the bridge to the distribution box are generally embedded in the top of the board with JDG tubes and JDG boxes.

⑦ The distribution box at the top of the thermocline generally leads from the distribution box at the bottom of the thermocline, and generally does not lead from the bridge;

⑧ PVC pipe binding: Commonly used PVC pipes are generally 4m long. If it is buried in cast-in-place concrete, it is necessary to apply special glue evenly at the position of the pipe joint, and bind it firmly with lead wires for binding steel bars on both sides of the pipe joint 15cm, with the middle part evenly spaced, and bind it twice. Attention; Try tying a steel bar.

PVC pipeline cannot be placed on the light box, which affects the protection thickness.

Try not to embed the whole PVC pipe in the beam, if the pipe is difficult to handle.

After the concrete pouring is completed, the upturned PVC pipe should be wrapped in concrete and painted to prevent the pipe from being damaged and bent, which will lead to the later excavation of the floor.

When embedded, the pipes should be tied and fixed separately at intervals, and not all of them can be tied together.

There are changes in the civil beam, which should be handled in time when pouring, otherwise it will be dug again in the future.

Strong and weak current bushings mainly check whether the quantity, size and distance from the bottom plate are qualified. In addition, check whether the casing is inclined, whether the length of the casing is too short and whether both ends are blocked.

The spacing between welding points of steel mesh shall not be greater than 0.6m, and whether all welding points on the same straight line are on the same steel bar.

Welded steel bars of steel mesh cannot be disconnected due to blockage of drainage riser or air outlet.

The temperature just welded is relatively high, and it is easy to burn the template. Pay attention to watering to cool down.

The ring beam of the equalizing ring shall be welded or bridged with the down lead of all columns.

Basic knowledge of hydropower

First, the construction preparation

(1) material requirements

1. Quality requirements of water supply pipes

(1) Indoor water supply system pipes shall meet the design requirements.

(2) The water supply pipe must be distributed.

(3) The materials involved in the domestic water supply system must conform to the drinking water hygiene.

Standard.

(4) Pipes and valves shall have technical quality appraisal documents or product certificates that meet the current national or departmental standards.

There should be no obvious defects such as corrosion, depression and distortion on the surface of steel pipe. Usually, when the thickness of the pipe wall is 3.5 mm, the surface of the steel pipe is not allowed to have 0.5 mm deep scars; When the wall thickness is 3.5 mm, the scar depth should not exceed 1 mm.

(5) Pipes, fittings, accessories and valves shall be visually inspected before use:

1) There shall be no defects such as cracks, shrinkage cavities, slag inclusion, folding and double skin on the surface of the steel pipe, and there shall be no pitting, corrosion or depression on the pipe wall that exceeds the negative deviation of the wall thickness.

2) There shall be no cracks, cold insulation, shrinkage or dislocation on the inner and outer surfaces of cast iron pipes, no sand sticking and protrusions on the socket parts, no depressions on the socket roots, and no sand sticking with a thickness of more than 2 mm and protrusions or depressions with a thickness of more than 5 mm on other parts.

3) The longitudinal scratch depth of the copper tube is not more than 0.3mm, and the horizontal protrusion height.

Or the depth of the depression is not more than 0.35 mm, and the area is not more than 0.5% of the surface area of the pipeline.

4) The specification and pressure grade of galvanized steel pipe threaded flange shall conform to the standard of cast iron threaded flange. The flange shall be made of gray cast iron, and the surface of the flange shall be smooth, with no defects such as bubbles, cracks, spots and burrs that reduce the flange strength and connection reliability. Flange end face should be perpendicular to the thread center line.

5) The internal and external walls of pipes and fittings of plastic pipes and composite pipes shall be smooth and level, free from bubbles, cracks and peeling, and the colors are basically the same.

6) The water meter case shall be cast regularly, without sand holes and cracks, without damage to the glass cover and complete lead seal.

2. Quality requirements of pipeline interface materials

(1) Flange connection gasket and bolt

1) The flange gasket is generally made of rubber plate, which should be soft in texture, free from aging and deterioration, and the surface should not be damaged or wrinkled.

2) The threads of bolts and nuts shall be complete, free from defects such as scars and burrs. Bolts and nuts should be well matched without looseness or jamming.

3) Cast iron water supply pipe socket interface material:

(1) Oil flax should be soaked and dried in 95% gasoline and 5% petroleum asphalt.

(2) Portland cement or slag portland cement slurry with a grade of not less than 42.5 shall be used for cement. Cement should be used within the validity period and stored in a dry place to prevent deterioration due to moisture. ③ The rubber ring should match the size gap of the socket. When installed, the compression ratio of rubber segment is 35% ~ 40%, and the rubber has good strength and elasticity without aging and deterioration.

④ The purity of green lead should be above 99%.

4) Water supply plastic pipe adhesive:

(1) must meet the hygienic standard for drinking water.

(2) It shall not contain lumps, insoluble particles and other impurities, and shall not gel and delaminate.

(3) Different types of adhesives shall not be mixed.

5) covered electrode, flux:

(1) covered electrode and flux should be selected according to the parent material.

(2) covered electrode, flux should have the factory certificate. Covered electrode should be dried according to the factory instructions before use and kept dry during use. Covered electrode coating should be free of shedding and obvious cracks.

(2) Thread interface filler

The filler of the threaded joint of the water supply pipeline is thick white paint or PTFE raw material belt. Hemp yarn should be made of flax with long fibers, and thick white paint should be clean without impurities and garbage. PTFE raw material belt should be qualified products, packaged into rolls and produced by certified professional manufacturers.

(2) Technical preparation

(1) Be familiar with and review the design drawings and related materials to understand the engineering situation.

(2) Investigation and analysis of original construction data.

(3) Prepare the construction organization design or construction scheme, clearly put forward the construction scope and quality standards, formulate a reasonable time limit for a project, and implement power sources such as water and electricity.

(4) Prepare the construction drawing budget and construction budget.

(3) Operating conditions

(1) The design drawings are complete (including standard drawings) and have passed the drawing meeting.

Review and design disclosure.

(2) The construction scheme has been compiled. In particular, the installation scheme of water tank should be closely coordinated with civil engineering; Attention should be paid to the import, export and hoisting conditions of water tanks in buildings, as well as the selection of site schemes for making water tanks.

(3) The construction technicians shall disclose the construction scheme and design drawings to the team and fill them in? Construction technical disclosure record? And issue it? Engineering task list? .

(4) The hard plastic pipe has low strength and high brittleness, so the plastic pipe should be installed after the installation of other pipes at the same installation site.

Basic knowledge of electrician 1, general part

1, what is a circuit?

The path through which current passes is called a circuit. The composition of the circuit generally consists of power supply, load and connecting parts (wires, switches and fuses).

2. What is a power supply?

Power supply is a device that converts non-electric energy into electric energy.

3. What is a load?

A load is a device that uses electric energy, that is, electrical equipment.

The connection part is used to connect the power supply and the load, which constitutes the middle link of the current path and is used to transmit, distribute and control the electric energy.

4. What is the basic concept of current?

When the charge flows in a certain direction, a current is formed. It is customary to stipulate that the direction of positive charge movement is the actual direction of current. A circuit with a constant current direction is called a DC circuit.

The amount of electricity passing through any cross section of a conductor per unit time is called current (intensity), which is represented by symbol I.

The unit of current (intensity) is ampere (A), the unit of large current is usually kiloampere (KA), and the unit of small current is usually milliampere (mA) and microampere (? A) indicate.

1KA= 1000A

1A= 1000 mA

1 ma = 1000? A

5. What are the basic properties of voltage?

1) The voltage between two points has a unique value.

2) The voltage between two points is only related to the position of these two points, and has nothing to do with the path of charge movement.

3) There are positive and negative voltages, which are related to the reference voltage direction of the symbol.

4) Walking along any closed loop in the circuit, the sum of the voltages of each section is constant to zero.

Basic knowledge of hydropower 1. Technical requirements for high-voltage system construction:

1. Installation location of distribution box: it should be installed in a well-ventilated and easy-to-operate location for daily operation and maintenance. The height from the bottom of the box to the ground should be1.8m. Under normal circumstances, the position of the original distribution box cannot be moved. If it is necessary to move, it is necessary to install an excess box, and the designer and the constructor will determine the scheme and carry out the construction under the guidance of the constructor.

2. Check the leakage protector and air switch: Check the leakage protector switch, and the power supply can be cut off when the leakage is 30mA, and the action time should be? 0.1.0s. Check the number and capacity of air switches. If it cannot meet the requirements, it must be replaced or added. Lighting electricity must be equipped with bipolar short-circuit protector, which is not controlled by the main switch of leakage protector. Air conditioners, vacuum cleaners and other outlets above 15A, as well as the commonly used five-hole outlets of 10A, must be controlled by the main switch leakage protector in addition to a unipolar short-circuit air switch.

3. Air conditioner: 2 or less (including 2) power cords are 4mm2, and sockets 16A. The power cord of all three machines is 4mm2. More than 5 air conditioning cabinets must be powered by three-phase five-wire system, and the main line should be at least 6mm2 flexible wires, with emphasis on grounding wire connection.

4. When installing the Yuba in the bathroom, the diameter of the separate shunt line is 2.5mm2, and the socket beside the water source is splash-proof. The diameter of the independent branch line in the kitchen is 2.5mm2 (if there are high-power appliances, the cross-sectional area of the conductor needs to be increased).

5. If the number of sockets and lamps exceeds 25, it is necessary to increase shunt control. If there are special uses such as computers, electric heaters and audio power supplies, it is advisable to use a fused socket.

This building has been used for more than five years, and all the wires must be updated. Test wire diameter less than 5 years: lighting? 1.5mm2, air conditioning? 4mm2, socket? 2.5Mm2, insulation resistance > 5m in insulation state? Generally available. 7. Construction requirements for slotting, switch, socket, box hole and threading:

(1) Pipeline wiring principle: horizontal and vertical, pipe cutting groove discharged into special flame-retardant electric conduit, pipe wall >; 1.5 mm. The catheter must be fixed in the catheter with wooden plugs, and the joint between the catheter and the catheter should be locked with locking buttons. Conductors must be inserted after conduit laying, and the grooving depth is 1.5 times the pipe diameter.

⑵ The number of bends shall be reduced as much as possible in pipe laying. Extra-long pipes must be wired. Now elbows must be bent by springs, and 90 elbows and tees are not allowed. Pipe connections shall be made by binding.

(3) It is forbidden to directly lay the conduit under the composite floor, carpet and floor tile in the kitchen and bathroom, and the conduit laid under the floor must be fixed.

(4) The total cross section of the conductor entering the conduit shall not be greater than 40% of the effective area of the conduit hole. According to the use requirements, what is the total number of wires in the conduit? 3 pieces, and there shall be no joints and twisted joints in the pipe.

5] into the box line must have a certain length, shall not be

Black, ground wire (PE) is yellow-green, and lamp cap wire is white.

(7) Section requirements of grounding wire (PE): the cross-sectional area of phase wire is below 16mm2, and the cross-sectional area of PE wire is the same as that of phase wire. The cross-sectional area of PE line above 16m2 is half of that of phase line.

Second, the weak current system construction technical requirements:

1. Telephone lines must be laid through pipes with dedicated telephone lines, and the number of service roads must be required? 2 routes. If there are insufficient routes, please supplement them.

2. The closed line of wired telephone must use coaxial cable (broadband is 5? ), and docking is strictly prohibited.

3. Note: The bending radius of the wired network road must be? 8D(R is 64mm).

Iii. Installation and positioning of electrical switches and sockets:

1. The height of the switch installation position from the ground should be about 1400mm, and the distance between the switch installed at the door and the door frame is

150? 200mm. The switch height of children's room should be 1000mm.

2. The installation position of the socket should be 300mm higher than the ground, and the socket connection should be grounded, with left zero and right phase. Switches, sockets and other devices should be installed firmly and correctly, with clearance from the wall? 1mm, the installation height difference in the same room? 5 mm. When the conductor is parallel to the interval between heating, hot water and gas pipes, it should be? 300mm, when crossing? 100mm, the distance from the electrical switch connector to the gas pipe? 300 mm.

3. After painting is completed, the switch and socket panel must be installed.

Four, hanging flat top line emission requirements: