Engineering site construction electricity consumption calculation method - Database & Sql Blog Articles

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Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

(1) Calculation of electricity consumption The total load of mechanical equipment equipped according to the project is 771.7kW. Consider all machines not used at the same time. According to the concrete pouring of the floor of the site, a concrete pump truck is required. Each pump is equipped with 4 vibrators for vibration. During construction, the peak period is:
Pi=4×90+1.5×16+14=398kW The internal and external lighting is calculated as 10%, which is 39.8kW. P meter = 1.24 × 0.7 (398 + 39.8) = 380kW
(2) Calculation of transformer usage:
There is a 10kW high-voltage line on the south side of the site, and the transformer can be set to 380 V / 220V.
P change = 1.05P meter / COSφ = 1.4P meter (1.05 power loss coefficient, COSφ power equipment power factor, generally take 0.75)
P change = 1.4 × 380 = 532kW
There is a 315kVA transformer on the site, which can be added one. The 315kVA transformer can meet the on-site construction power.
(III) Distribution line The total design of the distribution box is to adopt three-box five-wire system. Five-core copper cable is used between the main distribution box and each distribution box. The corresponding five-core cable is used for each distribution box to the electrical equipment.
(4) The wiring method of the protection system shall be directly connected to the neutral point of the low-voltage side of the geotechnical transformer in accordance with JG146-88 "Safety Technical Specifications for Temporary Use of Construction Sites", and shall be directly connected to the three-phase four-wire system and temporary power project. Protect the neutral TN-S zero-protection system, and make no less than 3 repeated grounding on the dedicated protection neutral, and repeat the grounding resistance value is not more than 10Ω.
(5) The structural laying of the cable line and cable line shall be designed in addition to the JEJL6-88 "Safety Technical Specifications for Temporary Use of Construction Sites", and the following requirements shall also be noted:
Buried cable line
(1) Select the shortest route and consider the location of existing and proposed buildings;
(2) Minimize the number of crossings of various pipelines, gaps, yards and weak electric cable lines;
(3) It shall not be damaged or corroded by various machinery, and the distance from the heat pipeline shall not be less than 2m;
(4) Easy to bury and repair;
(5) When installing the ground, a protective casing must be laid. The joint should be in a special junction box on the ground.
2. Cable selection
(1) The type of cable is selected according to the laying method and environmental conditions;
(2) The cable cross section must meet the requirements of interception flow, and the voltage drop at the end of the line should not exceed 5%.
(6) Selection and arrangement of distribution boxes
1. All distribution boxes on the site are equipped with standard distribution boxes produced by the designated manufacturers of the safety supervision station, and the designated signs and uniform numbers are painted on the cabinet.
2. The main distribution box is located close to the power supply place, the distribution electric box is located in the place where the power consumption is relatively concentrated, the distance between the distribution electric box and the equipment switch box does not exceed 30m, and the switch box and the controlled electric equipment The horizontal distance is no more than 3m.