I. Composition of Electrical Equipment Installation Project Generally, electrical equipment installation project is an engineering system formed by receiving, transforming and distributing electric energy, and then utilizing or distributing it to electrical equipment. According to its main functions, it can be divided into electric lighting system, electric power system, power distribution system and so on. This kind of engineering system, which focuses on the transmission, distribution and use of electric energy, is usually called high-voltage engineering. 1. Electrical lighting system The electrical device that converts electrical energy into light energy constitutes a lighting project. Including industrial and mining enterprise lighting and civil building lighting. Lighting system can be divided into general lighting system, local lighting system and mixed lighting system. The scope of electric lighting system generally includes: power supply introduction-control equipment (distribution box)-distribution line-lighting (device). 2. Lightning protection and grounding system (1) Lightning protection device Lightning protection device is a kind of protection device to protect buildings, structures and equipment from lightning damage, which usually consists of three parts: lightning arrester (lightning rod, lightning protection network) or lightning arrester, connecting wire (down lead) and grounding device. (2) Grounding device The grounding device consists of a grounding body and a grounding wire (grounding bus). Grounding of electrical equipment is usually divided into working grounding, protective grounding, protective grounding, repeated grounding and lightning protection grounding according to its functions. 3. Power system Power system is an electrical device that applies electric energy to the motor to drag various working equipment or uses electric energy as energy for production, such as high and low voltage or AC and DC motors, lifting electrical devices, automatic dragging devices, etc. Power engineering usually works in a workshop or factory building, and its scope is: power supply introduction-various control equipment-distribution lines (including secondary lines)-wiring of motors or electrical equipment-grounding, debugging and so on. 4. Power transformation and distribution system Power transformation and distribution system is the general name of electrical devices used to convert and distribute electric energy, and consists of two parts: power transformation and distribution equipment and distribution equipment. As a unit project, the power transformation and distribution system generally covers the whole project content from the power grid access point to the power distribution point, including lighting, grounding and lightning protection devices in the system. Second, the common electrical materials and equipment 1. Material constant distribution system is the general name of electrical devices used to convert and distribute electric energy, which consists of substation equipment and distribution equipment. As a unit project, the power transformation and distribution system generally covers the whole project content from the power grid access point to the power distribution point, including lighting, grounding and lightning protection devices in the system. 2. Equipment Common electrical equipment includes: complete sets of high-voltage switchgear and low-voltage power distribution panels, boxes and screens, porcelain bottles supported by buses accompanying the equipment, combined box-type substations, power transformers, high-voltage disconnectors, high-voltage circuit breakers, high-voltage fuses, transformers, power capacitors, batteries, etc. Three. Electrical construction drawings 1. Composition of Electrical Construction Drawings The construction drawings of electrical equipment installation projects generally include power distribution drawings, power engineering drawings, lighting engineering drawings, electrical engineering drawings and lightning protection and grounding engineering drawings. Electrical construction drawings are generally composed of foundation drawings and detailed drawings. (1) Basic Drawings The basic drawings in the electrical construction drawing include drawing catalogue, construction drawing description, system drawing, plan drawing, elevation (section) drawing, control schematic drawing, etc. The list of equipment and materials also belongs to the scope of basic drawings. (1) Description of construction drawing In the electrical construction drawing, the construction description generally indicates the power supply mode, voltage grade, trunk laying form, installation height of various electrical equipment, main technical data of the project, construction and acceptance requirements and related matters. (2) List of main equipment and materials The list of equipment and materials lists the names, models, specifications and quantities of all kinds of main equipment, pipes, wires and other equipment required for this project, which is the basis for ordering main equipment and materials. (3) Electrical system diagram The electrical system diagram is drawn according to the composition and distribution mode of electrical engineering. It generally represents the circuit diagram of the power supply and distribution lines of the whole project in the form of single-line connection, and does not represent the specific spatial position relationship between electrical equipment and electrical lines. (4) Electrical plan Electrical plan generally includes power distribution plan, power plan, lighting plan, weak current (telephone, broadcast) plan, outdoor electrical plan, standard floor plan and trunk line layout plan in high-rise buildings. ⑤ Control schematic diagram is used to control and protect electrical equipment, which is generally called control electrical equipment. Control schematic diagram is a circuit development diagram drawn with specified graphics and text symbols according to the working principle of control electrical appliances. Generally, the specific installation space position of electrical components is not indicated. (2) Details ① Details The details of electrical engineering are mostly the panel layout of distribution boards (boxes, boards), control panels and some installation parts. (2) Standard drawing A standard drawing is a detailed drawing with general properties, indicating the specific drawings and detailed dimensions of a group of equipment or components, which is convenient for production and installation. 2. The characteristics of electrical construction drawings Electrical construction drawings are different from mechanical engineering drawings. The general electrical plan is drawn on the simplified civil plan, and there are also some electrical system diagrams, schematic diagrams and wiring diagrams. The characteristics of electrical construction drawing are: (1) Sketch is the main form of electrical construction drawing, that is, a diagram showing the relationship between systems or equipment with graphic symbols, marked frames or simplified shapes. (2) Graphic symbols, text symbols and project codes are the basic elements of electrical construction drawings. (3) Electrical devices and electrical systems are mainly composed of electrical components and electrical connection lines, so electrical components and electrical connection lines are the main contents described in the electrical construction drawing. (4) Position layout method and function layout method are two basic layout methods in electrical construction drawing. (5) The shapes and sizes of electrical equipment and circuits are not drawn to scale in the plan, and are usually represented by legends. Four. Composition and matters needing attention of budget quota for electrical equipment installation project 1. Composition, for example: 2. Problems that should be paid attention to when using quota (1) to calculate unpriced materials. In the quota, most unpriced materials in the budget quota of electrical equipment installation project are main materials. The materials in brackets in the quota are unpriced materials, and their value should be calculated separately when budgeting; For the main materials whose consumption is not listed in the quota, the consumption should be increased according to the consumption of construction drawings and the specified consumption expenses when preparing the budget. (2) Scaffolding erection and dismantling expenses For electrical equipment installation projects (except overhead lines below 10kV), scaffolding erection and dismantling expenses shall be calculated as 4% of engineering labor costs, of which labor wages account for 25% of erection and dismantling expenses. That is, scaffold erection cost = engineering labor cost ×4%, of which labor cost = scaffold erection cost ×25%. The calculation base is the labor cost of each sub-project, extra-high increase fee and high-rise building labor cost. (3) Extra-high cost of the project, except for the sections where aerial work factors have been considered in some sub-projects, if the installation height of the working object is more than 5m but less than 20m of the building floor, the extra-high cost of the project shall be calculated as 33% of the extra-high labor cost, that is, the extra-high cost of the project = extra-high labor cost × 33%. (4) The extra-high cost of the high-rise building of the electrical equipment installation project shall be calculated as specified in Table 2.2. The expenses are all artificial wages. (5) The increase of installation and production at the same time and the increase of construction in an environment harmful to health belong to labor cost, and its calculation formula is: the increase of installation and production at the same time = (labor cost of each subproject+labor cost in the increase of subtitle coefficient) × 10% increase of construction in an environment harmful to health = (labor cost of each subproject+labor cost in the increase of subtitle coefficient). When compiling the valuation of electrical equipment installation project, in order not to make the engineering project set the wrong quota and omit the calculation of engineering quantity, the whole electrical engineering subsystem should be divided into subprojects and the engineering quantity should be calculated separately. Electric lighting system 1. Lighting control equipment The control equipment of electrical lighting engineering mainly refers to the lighting distribution box, panel and various control switches, fuses, measuring instruments and wiring in the cabinet. Lighting engineering control equipment installation is divided into sleeve control equipment installation and single control equipment installation. 2. Piping, wiring piping and wiring refer to the laying of distribution lines and the laying of protection pipes for distribution lines in electrical equipment installation projects. (1) Piping work includes: positioning, marking, drilling, burying bolts, sawing pipes, wrapping wires, bending, piping, gouging, plastering mortar protective layer, grounding and painting. The horizontally laid pipeline shall be based on the center point of the pipeline direction, laying position and equipment installation position in the construction plan, and the length of the pipeline shall be calculated by borrowing the axis dimensions of the wall and column marked on the plan. If there is no available shaft size, use a ruler or ruler to directly measure the length of the pipeline on the plan, as shown in the figure. For vertically laid pipes (led up or down along walls and columns), the length of the pipes should generally depend on the floor height and boxes, cabinets and trays. In the figure, the installation height of the distribution box is 1.5m from the ground, and the socket is 0.3m from the ground. The piping from the distribution box to the socket is laid along the wall and underground, and the buried depth is 0.1m; Then the length of the whole pipeline is: 1.5m (the bottom of the box is vertical to the ground) +0. 1m (vertical depth into the ground) +L 1 (horizontal distance from the distribution box to the left socket of the middle wall can be measured with a ruler on the drawing) +0. 1m (vertical depth out of the ground) The available scale can be measured on the drawing) +0.4m (vertical outlet into the socket) +0.4m (vertical outlet into the socket) +L3 (horizontal away from the right wall socket, the available scale can be measured on the drawing) +0.4m (vertical outlet into the socket) (1) The wiring engineering quota is composed of in-pipe threading, porcelain splint wiring and plastic splint wiring according to different wiring forms. (1) In-pipe threading is divided into lighting circuit, power circuit and multi-core flexible conductor, and projects are divided according to conductor material, conductor cross-sectional area and core number. The lighting line shall pass through the pipe, and the quota is 2-1169 ~1173. When the cross-sectional area of the conductor is greater than or equal to 6 square millimeters, the corresponding project of the power line shall be implemented. Thread the power conduit with the quota of 2-1174 ~1211. The threading quota of multi-core flexible conductor is 2-1212 ~1226. Units of measurement of engineering quantity: 100m, 100m/ bundle, and the engineering quantity is calculated according to the linear meter of single line (bundle) shown in the construction drawing. The calculation of pipe threading engineering quantity can be carried out at the same time as the calculation of piping engineering quantity, and the calculation formula is as follows: pipe threading engineering quantity = single-line length of pipe threading (m)÷ 100② The plastic sheath line open wiring quota project is divided according to the building structure, the number of sheath line cores (two cores and three cores) and the cross-sectional area of a single wire core, and 2- 1365438 is suitable for use. For example, if the plastic sheath line BVV-2× 2.5 is laid on the wooden structure, the norm is 2- 13 13, and if it is laid on the brick-concrete structure, the norm is 2- 13 19. Unit of measurement of engineering quantity: 100m. The engineering quantity is calculated according to the extension meters of two-core and three-core lines shown in the construction drawing, including the horizontal and vertical lengths of beams, columns and vertical directions plus the specified reserved line length. (2) The junction box and box shall be installed in the piping and wiring project, and the installation of line junction box (junction box), switch box, lamp holder box and socket box is both open and concealed. The quota of junction box is divided according to different specifications (half circumference) of surface-mounted, concealed and junction box, and 2-1373 ~1376 is applicable when using; Junction boxes are divided into subheadings according to junction boxes, switch boxes, ordinary junction boxes, explosion-proof junction boxes, junction boxes on steel cables, and surface-mounted concealed fittings, and 2-1377 ~1381 For example, the concealed switch box is 2- 1378, and the concealed lamp holder box is 2- 1377. Quantity measurement unit:10; The engineering quantity shall be calculated according to the quantity shown in the construction drawing, or according to the requirements of construction technology and specifications. The line junction box (junction box) is made at the branch of the pipeline or at the bend of the pipeline. The concealed switch and socket should have switch junction box and socket junction box, and the concealed electric pipeline should have lamp holder junction box at the lamp position. Steel pipe with steel junction box, plastic pipe with plastic junction box.
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