Graduation practice is to complete the final phase of the university's course to be the most important section of the Practice. Practice is every qualified students must havean experience that allows us to enhance professionalism in the practice of awarenessand practice of awareness. We practice during the process of training units in theschool and support, more guidance of experts, through training we learned a lot in class, not simply the knowledge of school for our future design and lay a solid foundation. At the same time allow themselves to contact the school for the purpose ofinternship training of our ability, the five-week internship to increase their ability to havea lot of knowledge, greatly improved.
Internship is designed to improve the ability of students and social contacts and to understand and master, verify and consolidate learned basic course content. Enable students to understand the modern high-rise building design and the actual construction of electrical easy to ignore the problem, students integrate theory with practice, love the professional, enthusiastic, committed to thinking of China's modernization drive.
To achieve the above objective practice, practice the main content should include:
1. Understand the internship process and production organization of productionmanagement.
2. Understand the performance of some electrical products and features.
3. Control low-voltage distribution system design, weak part of the design, lighting,part of the design, dynamic part of the design, lightning protection and grounding part of the design.
4. Institute of electrical equipment used in operating methods and the basic working principle.
Although this practice is only 3 weeks time, but during that time, the theory for somecommon things, with perceptual awareness, feel benefit.
Here are some of my summary of the internship period, and their feelings and experiences. To carry out their work in the future, and the future work of great help tome.
Visit the West Campus, Dongsheng Building and City Hall and linear low-voltagepower distribution room, and the laying of the roof there are weaknesses in the design of some of mine. Now I will explain in detail the building of the lightning protection and grounding
1. Basic principles:
Lightning protection design of technical measures should be the existing national standard "lightning protection design of buildings" for Lightning Protection, refer to "Building Lightning Protection Design Standard" corresponding requirements, the use of ball lightning rod protection method, the use of other potential join the most important safety measures.
2. Anti-cloud-to-measure, should meet the following requirements:
(1) air terminals using the lightning rod, lightning protection zone (network), or a combination of both, it should be used as a metal roof building air terminals, but should be consistent with regulatory requirements. Containing radioactive material should not be used air terminals. The elimination of other forms of lightning, it should only be used with high pole tower roof was added to our building on. Protrusions on the roof, such as satellite and receiver antenna, holiday lights, aviation obstruction lights and air-cooled unit, the roof should be in the range of lightning protection devices, if not calculated by ball within the scope of protection should be separate lightning rod, with protection, lightning protection device connected with the roof.
(2) deflectors should give priority to the use of reinforced concrete building columns or shear walls in the main bar, but also should use the building on fire ladders, steel columns, metal chimneys, etc., as deflectors.
When the use of steel in reinforced concrete columns, steel columns as a natural drop, and also used as a grounding device based steel with no disconnect card, but it should be located in a number of suitable locations outside the bar connected with the column connecting plate, for the measurement, an external artificial grounding and equipotential bonding for use.
Brick buildings surrounded by a separate deflectors in the external walls and the installation of 1.8 meters from the ground disconnected card. The 1.7 meters to 0.3 meters underground for some protective measures should be taken.
(3) The use of grounding devices should give priority to the building of reinforced concrete base. A reinforced concrete ground beam, should in the beam reinforced with a ring grounding device; not reinforced concrete ground beam, it can not in the building surrounding strip of reinforced concrete base closed, galvanized flat steel with a direct lay-40x4 pit in the outer groove to form a circular grounding.
When the transformer and the work of the diesel generator neutral grounding, electrical protective earth grounding system work and share weak grounding device, the grounding resistance should be less than 1 euro. Use common grounding, the weak systems should their equipment room, and building insulation grounding stud, with more than 25 mm2 copper cable or wire welded steel pipe made through a separate drop, the foundations of buildings connected with the ground plate. Weak system of general requirements for grounding resistance of less than 4 ohms, should be an independent ground system view often Boxu Chile to catch car owner thereupon low ash wood ho chant argon ∮? 0 meters.
3. Sideswipe against mine measures should meet the following requirements:
Height over 30 meters of reinforced concrete structures, steel structures, should take the following anti-swipe mine and equipotential bonding of the protective measures:
(1) steel frame and reinforced concrete should be connected to each other;
(2) should be used within the steel column or reinforced concrete columns reinforced as a lightning protection device deflectors;
(3) should be 30 meters and over the railings on the external walls, doors, windows and other large metal objects and lightning protection device is connected;
(4) vertical laying of metal pipes and metal top and low-end devices to be connected with the mine;
(5) columns and ring beam without the buildings, walls should be laid at intervals of around three out of galvanized round steel ¢ 12 to do the grading rings, a combination of columns and ring beam, the use of steel for the ring beam grading ring. All the building every three vertical metal pipe connected with a grading ring. Grading ring should be connected with the lightning protection device deflectors.
4. Lightning induction of measures, should meet the following requirements:
(1) The protection of metal objects within the building ground, is the main measure lightning induction. Therefore, the building housing the equipment, pipelines, and other major metal frame should be close to receiving the grounding or electrical equipment, lightning protection grounding device
(2) parallel to the laying of pipes, cables metal jacket structure and a long metal object, the spacing is less than 100mm should be used jumper wire, cross-junction spacing should not exceed 30m; crossing clearance less than 100mm, the should be across the intersection.
5. Lightning invasion wave of measures, should meet the following requirements:
(1) line of low voltage lines should be buried with the cable directly into the home end of the cable jacket or the protection of metal pipe on the device receiving the lightning protection and grounding; if connected to overhead lines should be changed into the household 50m cable, cable for connection at arrester should be installed, and with the cable metal sheath, steel and iron insulator feet, fittings, etc. together, the impulse grounding resistance should not exceed 10 ohms. If overhead wires are used, the arrester should be installed into office.
(2) overhead and underground metal pipes, should be in and out of buildings and lightning protection grounding device connected at.
Fixed on the building of holiday lights, aviation obstruction lights and other electrical equipment of the line, should be based on the importance of building the mine to take corresponding measures invasive radio waves:
a. no metal or electrical equipment protection network should cover the protection of air terminals within;
b. The line leads from the distribution box should wear steel. Ends of the pipe is connected with metal distribution box; the other side of the metal casing and electrical equipment, protective cover is connected, and lightning protection devices connected to your nearest roof. Pipe should be located off the middle of the jumper.
Third, and experience
This internship, I learned that the size of the plant level, the production process and the production of some conventional products, the study design in the future I believe there will be more help.
In addition, I feel that through this internship for me after the choice of electrical equipment, lighting, power, systems, lightning protection and grounding aspects of the design will be very helpful thank the school and the teacher gave us this Gui internship opportunities.