The main electrical equipment to be commissioned are: high-voltage distribution cabinets, high-voltage switches, surge arresters, current transformers, voltage transformers, a variety of measurement and protection meters, power transformers, transformer oil, busbar, insulators and bushings, reactors, power capacitors, power cables, grounding devices, low-voltage distribution cabinets, a variety of relays, microcomputer integrated protector, relay protection system, low-voltage circuit breakers and isolators, proximity switches, various sensors, various sensors, and all kinds of electrical equipment. Relay protection system, low-voltage circuit breakers and isolators, proximity switches, a variety of sensors, a variety of pumps and fans, various types of machine tools, various types of lifting equipment, a variety of motors, a variety of frequency converters, a variety of types of PLC, a variety of soft starters.
[Electrical commissioning of the basic theoretical knowledge required]
The staff engaged in electrical commissioning should know the basic principles of electrical engineering, know the general electrical instrumentation, high voltage test technology, power distribution systems, power system engineering basics, high / low-frequency electronic circuits, the principle of intelligent instrumentation and applications, sensor knowledge, electronic control components and the basic performance of electrical equipment, motors and dragging knowledge, electrical transmission control systems. Drag knowledge, electrical drive control system, industrial automation, inverter principle and application, programmable controller. Should also have a certain degree of electromechanical installation and general electrical safety knowledge.
[Electrical commissioning of the basic projects and links]
Basic test items include:
1. insulation resistance and absorption ratio measurement;
2. DC withstand voltage test and leakage current measurements;
3. AC frequency withstand voltage test;
4. dielectric loss angle measurement;
5. capacitance Measurement of capacitance ratio;
6. Measurement of DC resistance;
7. Determination of polarity; Determination of wiring group;
8. Measurement of ratio;
Basic electrical commissioning mainly includes the following:
1. Tests on high-voltage equipment;
2. Commissioning of high-voltage power distribution system;
3. High-voltage transmission system debugging;
4. Low-voltage power distribution system debugging;
5. Low-voltage transmission system debugging;
6. Computer system debugging;
7. Individual debugging;
8. System debugging;
After the completion of the above eight links in the commissioning of the work, and to confirm that the engineering specifications are achieved, before the production Production. Must strictly refer to the national standard "electrical installation project electrical equipment handover test standards", in addition must meet, meet the design requirements.
[Electrical commissioning of the preparatory work]
In order to ensure safety and quality, before the commissioning work, should also carry out adequate technical preparations, especially for the more complex system of electrical commissioning work, the quality and duration of the work depends largely on how the technical preparation.
Technical preparations are as follows:
1. study and review of drawings;
2. organization of technical studies;
3. preparation of adjustments to the test program (including safety measures);
4. preparation of instrumentation and tools and materials;
5. understanding of the system's basic technology (not mandatory);
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Electrical commissioning work can be a better combination of theory and practice, but the level of commissioning technology, mainly through practice. Complex electrical drive control system is often adjusted through a number of tests and production practice in order to complete; through the adjustment test, you can also find the design, equipment and installation of certain defects. In the adjustment of practice requires commissioning personnel to accurately verify the safety system and its rationality of each link, and research to improve the process to meet the requirements.
In order to better complete the adjustment of electrical engineering test work, according to the specific circumstances, the organization of appropriate commissioning professional team is necessary. Electrical instrumentation is the main tool to adjust the test personnel, in addition to their careful use of the scene to pay attention to the careful use and safekeeping, but also should be set up special personnel for safekeeping, maintenance and overhaul, in order to ensure that the instrumentation is often in a good state, to extend the service life, to reduce the error to meet the needs of the project.
For high-pressure experimental equipment, because often stored on-site, frequent transportation, in the absence of special custody and use of the conditions, should be made regular inspection and repair.
[General requirements in the electrical commissioning]
1. According to the drawings to check the equipment, components, power lines and operating lines, plc signal line type specifications, and the components of the contact capacity, stroke and contact.
2. Accurate validation of the line. All lines must comply with the drawings.
3. Terminals must be pressed, and no more than 3 connectors may be connected to the same terminal. Special treatment is also necessary in special environments, such as coal production.
4. The wire end must be hung on the line number, which is required to be clear and accurate.
5. All secondary wiring must pass through the terminal block. Special circumstances need to be welded and insulated.
6. Electrical commissioning instrumentation should meet the requirements, the general accuracy of 0.5 level or higher.
7. belonging to the external magnetic field is susceptible to the influence of the instrument, should be placed outside the high-current wire 1 meters away from the measurement.
8. Where the measurement is related to the temperature, must accurately measure the temperature of the test object. If the temperature of the test object is not easy to be measured, you can measure the ambient temperature.
9. insulation test should be selected for good weather.
10. All the equipment to be tested, before and after the voltage resistance should be checked for insulation resistance, if not otherwise specified, the duration of the AC withstand voltage test is specified as 1 minute.
11. When measuring the dielectric loss angle and capacitance ratio of the transformer and conducting the withstand-voltage test, all the taps that can be connected to the coil of the test object shall be connected to each other. Boosting test should be untested coils all grounded (measured dielectric loss angle and capacitance, the untested coil should not be grounded).
12. Electrical equipment and components in addition to the specified items for the test, in the factory data put forward special requirements should be in accordance with the manufacturer's test.
13. In recording a variety of characteristic curves, the number of measurement points should be sufficient to depict a smooth curve.
14. If the equipment quality is not good, after adjustment still can not meet the manufacturer's technical requirements, generally shall not be used.
15. Where the equipment can be divided into phases should be divided into phases in order to compare each other.
[General requirements for electrical commissioning single commissioning and system commissioning]
1. Check the insulation of all circuits and electrical equipment.
2. Remove all temporary short wiring and various obstacles.
3. Restore all temporarily disconnected wires to their normal condition and check again for looseness or detachment and deal with them.
4. Check the system control, protection and signaling circuits again for empty operation, all equipment and components of the movable part should be flexible and reliable.
5. Check the standby power lines and standby pumps and automatic devices should be in good condition.
6. Check whether the contact position of travel switch and limit switch is correct, whether the rotation is flexible, and whether there is any foreign matter inside, and cover them well.
7. In the motor before idling should be manually disk car, rotation should be flexible, and carefully inspect the internal existence of obstacles.
8. Energized test drive is necessary to confirm that the test link within the staff. Must require the entire link no one work. As a safety first.
9. If the start of the motor has a greater impact on the power grid, before the start should be notified to the substation staff or the relevant power supply department.
10. For large substations and large motors should be made before the power supply program (including safety measures). The approval of the relevant departments should be obtained before power delivery.
11. With the mechanical test drive, should be subject to the installation of the designated person command.
12. When sending power, the main power supply should be sent first, then the operating power supply, and vice versa when cutting off.
13. The motor should be started with the gate closed when driving fans, pumps and other load machinery.
14. Electrical commissioning personnel should be divided responsibility, and prepare the necessary safety equipment.
15. Ensure that the commissioning process of each post contact smooth.
16. Commissioning process, the operator must stand firm, ready to emergency stop at any time.
17. Electrical commissioning process must accurately record the parameters, make good electrical commissioning records.