Introduce in detail: electrical installation and installation process

(1) PDC installation

1. Cabinet installation and construction process

Construction preparation -- Unpacking points -- basic security -- stable installation of cabinets -- wiring in cabinets -- pre-test inspection -- commissioning and running

2. Preparation for construction

(1) The ground construction of the distribution room has been completed, and there is no water and debris in the indoor trench.

(2) The embedded parts and reserved holes meet the design requirements, and the embedded parts are firm; The doors and Windows are installed and meet the fire protection requirements.

(3) The decoration work that is likely to damage the installed equipment or can no longer be constructed after the installation of the equipment has been completed.

3. Unpack and point parts

(1) This work shall be composed of the owner, the supervising engineer, the contractor and the equipment supplier, who shall jointly conduct the point inspection and make a record.

(2) Check whether there is any damage during handling before unpacking.

(3) After unpacking, check whether the equipment is consistent with the original design, whether the spare parts are complete, whether there is damage, etc., whether the random document list and spare parts are complete, and whether the electrical components are damaged or other abnormal conditions.

4. Basic system security

(1) Test the installation position of the power distribution room, check whether the location and size meet the requirements of equipment installation, verify the distance between the front and back of the cabinet, and solve any problems immediately.

(2) Installation of basic channel steel

1) Measure and straighten the channel steel, and remove the rust on the channel steel;

2) According to the construction drawings and equipment drawings, the basic channel steel frame is processed. During the processing, the size of the frame is tested to ensure its geometric size.

3) For the processed foundation, brush oil and other anti-rust treatment.

4) Install expansion studs next to the installation position of the equipment foundation channel steel. According to the elevation of the civil ground, the highest group is measured with the level, and it is correctly positioned and fixed firmly with the expansion bolt after adjusting the level.

5) This channel is used as the reference point to determine the position and height of the rest of the channel steel, and after adjustment, it is firmly fixed with the expansion bolt.

5, cabinet stable installation

(1) According to the cabinet numbering sequence specified in the design drawing and the surrounding dimensions of the base, check whether the base size is consistent with the size of the cabinet and meets the specified requirements.

(2) Use a level and magnetic cable to vertically adjust the cabinet to the correct position. For complete sets of cabinets, the order of adjustment can be left and right first, or the middle cabinet can be adjusted first, and then adjusted separately to both sides.

(3) After the cabinet is in place, first find the cabinet at both ends, and then tighten a horizontal line from the bottom of the cabinet to the top two-thirds of the cabinet, and adjust it one by one. When the cabinet height is inconsistent, the cabinet surface can be adjusted.

(4) To adjust the alignment, 0.5mm steel gasket can be used to find a flush, each gasket is not more than three pieces.

6, cabinet wiring

(1) Bus bar connection in the cabinet

1) Check whether the contact surface is smooth, clean and free of oxide film before installation. Check and tighten the bolts of the main bus cable and the electrical contacts in the cabinet before putting them into operation.

2) The phase sequence between the bus bars is arranged in a uniform, and the bus bar color code is correct.

(2) Secondary control cable connection

1) Check whether all electrical components of the cabinet are consistent with the design according to the schematic diagram before the secondary wire connection.

2) Check whether the manufacturer's wiring is correct according to the wiring diagram.

3) After the cable is laid, it is listed according to the drawing number, and the cable plate indicates the cable model, specification and location.

4) Wiring according to the wiring diagram, cable binding, fixing beautiful and firm, secondary wiring accurate.

7. Check before test

(1) Clean out the tools and sundries in the cabinet, and clean the inside and outside of the cabinet.

(2) The fastening screws of the electrical components are firm, and the operating mechanism such as the knife switch and the air switch is flexible to prevent the phenomenon of hysteresis or excessive operation force.

(3) Check whether the switching electrical equipment is reliable, the contact surface is in good contact, and the auxiliary contact is accurate and reliable. The ratio between the electric instrument and the transformer, and the polarity should be connected correctly and reliably.

(4) The bus connection should be good, and its insulation support parts, mounting parts and accessories should be installed firmly and reliably.

(5) Check whether the core specification of the fuse is selected correctly, whether the setting value of the breaker meets the design requirements, and whether the action is accurate and reliable.

(6) Measurement of insulation resistance, measurement of busbar and ground resistance, measurement of secondary line and ground resistance, should conform to the provisions of the current national construction acceptance code. When measuring the secondary circuit resistance, other semiconductor components should not be damaged, and the insulation resistance should be disconnected when measuring.

(2) Steel pipe laying process

1. Preparation for construction

(1) In the process of civil structure construction in this project, in the preliminary preparation stage, actively do a good job of interface cooperation.

(2) Coordinate with the civil engineering profession to ensure that the buried pipeline is installed in place before the construction of the structure.

(3) Investigate the construction site to ensure the needs of the construction power supply and site during the construction phase, and ensure the entry of materials and equipment.

(4) Coordinate the arrangement of man-machine materials according to the actual situation of small site construction work surface.

2, dark pipe construction method

(1) It is strictly forbidden to use gas and electric welding to cut the steel pipe, and tools such as hacksaw or grinding wheel saw must be used to make the fracture level and not crooked, and then use a flat file to file the cut off place, and the inner wall of the pipe mouth is smooth with a round file to ensure that the inner wall of the pipe mouth has no sharp corners and burr.

When the steel pipe is bent, when the nominal diameter of the steel pipe is greater than 32mm, it is required to use an electric or hydraulic pipe bender. The steel pipe with nominal diameter less than 25mm can be bent manually.

(2) When the steel pipe is covered with wire, the pipe is firmly clamped with a vice, and then the twisted plate is set on the end of the pipe, uniform force, and the cooling liquid is poured with the sleeve, the wire buckle is not chaotic after forming, but long, when the pipe diameter is 20mm and below, it should be divided into two plates, and when the pipe diameter is 25mm and above, it should be divided into three plates.

(3) Determine the position of the box

Steel pipe into the box first determine the installation position of the box and box, in strict accordance with the design elevation with civil decoration to determine the laying position of each appliance, pay attention to the height of each elevation refers to the building elevation, the size of the appliance from the top or ground refers to the bottom elevation of the appliance, the switch height does not include the height difference between the switch panel and the box side.

(4) Steel pipe connection and laying requirements

The connection of the hidden steel pipe is to be connected by steel sleeve arc welding. The length of the casing should not be less than 2.2 times the outer diameter of the corresponding pipe, and the circumference of the casing should be sealed and welded. To ensure that the interface of the steel pipe is tight and seamless and located in the center of the casing, mark the length of the casing with a red pencil and saw mark on the end of the pipe to be fitted before welding. After the casing is welded and fixed, use the casing length identifier on the steel pipe to check the gap between the steel pipes, and remove the welding slag after welding. Pipelines, pipe openings and pipe joints laid in dusty and humid places should be sealed.

The pipeline should be laid along the nearest line and should reduce bending; The clear distance between the pipe buried in the wall and the surface should not be less than 15mm. When laying, the crossing should be minimized. If the crossing is necessary, the large diameter pipe should be placed under the small diameter pipe.

(5) Steel pipe into the box and box

When the steel pipe is connected to the equipment, add galvanized pipe hoop and hose joint to the end of the steel pipe in the indoor dry place, and then introduce it with a protective hose; For indoor humid places and outdoor, add a waterproof elbow at the end of the steel pipe, bend the wire protection hose into a dripping arc and lead it into the terminal box of the equipment. The pipe mouth connected with the equipment is 150-250MM higher than the electrical junction box of the equipment.