Basic knowledge of high voltage electrician 1. Basic knowledge as a high-voltage electrician
You mean to let you be on duty and overhaul in the substation, right?
Being on duty is very simple. Look at the equipment all day If you encounter operation, you have to be careful and ask the unit to prepare insulating gloves and boots. There are some basic operating rules. For example, it is forbidden to switch on and off with electricity, and the grounding knife switch and the main knife switch cannot be closed at the same time, some of which are not detailed.
It is not difficult to repair. In the power system, accidents are rare, and accidents are generally serious (hehe, don't be afraid). If you can't repair it yourself, let the unit spend money to find a power supply company to repair it. There are also some basic rules, such as CT can't open the circuit, PT can't short circuit, and I won't elaborate on others. After all, you didn't give so many points, hehe ~
Find some books to read. In terms of substation operation and maintenance, maintenance electrician belongs to low-voltage electrician and power supply system, and high-voltage electrician belongs to two industries. Power supply is more difficult, and it is easier to turn to dry electricity after power supply. If you switch from electricity to dry power supply, you will enrich yourself. Good luck. Everything upstairs is right. Safety comes first. You are not afraid of running out of firewood, hehe.
2. What should a high-voltage electrician learn?
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Original publisher: Jiang Yong
High-voltage electrician training data content Chapter I, Chapter III, Chapter V, Safety Production Management, Electrician Measurement, Electric Shock Prevention Technology Chapter II, Chapter IV, Chapter VI, Chapter VIII, Electrical Safety Chapter X Electrical and Electronic Foundation, Electric Shock Danger and First Aid Protection, Grounding and Protection of Zero Electrical Fire, Power transformation and distribution system and lightning protection and anti-static line safety Chapter VII Electrical safety operation technology Chapter IX Power capacitor Chapter IX XI Hand-held electric tools safety Chapter XII Chapter XIII Chapter XV High-voltage power transformer distribution device Chapter XIV Chapter XVI Transformer overvoltage protection Chapter XVII Relay protection and secondary circuit Chapter I Safety production management Section I People's Republic of China (PRC) safety laws and regulations People's Republic of China (PRC) Safety Law On June 29th, 2002, the 28th meeting of the 9th the NPC Standing Committee adopted the safety production law: adhere to the principle of safety first, prevention first and comprehensive management; The principle of "three simultaneities" for safety facilities of new construction, renovation and expansion projects; The safety training regulations for production and business units are1; The primary safety training time for the principal responsible persons and safety production management personnel of non-high-risk production and business operation units is not less than 32 hours, and the annual retraining time is not less than 65438+. The safety qualification training time of personnel in high-risk units shall not be less than 48 hours, and the annual retraining time shall not be less than 16 hours. 2. The pre-job training time for new employees of non-high-risk production and business operation units shall not be less than 24 hours; New employees of high-risk production and business operation units shall receive no less than 72 hours of pre-job training and no less than 20 hours of annual retraining. 3. The new employees of the production and business operation units must go through three-level safety training and education in the factory (mine), workshop (section, area and team) and team before taking up their posts. Section 2 electrician's safety responsibilities 1. Electrical work refers to the operation, maintenance, installation, overhaul, transformation, construction and debugging of electrical equipment (excluding electricity).
3. What is the basic knowledge of electrician?
Three-phase five-wire system uses yellow, green, red and light blue to represent U, V, W and N protective grounding wires respectively. When the transformer is running, each phase current of the transformer should not exceed the rated current. The maximum unbalanced current shall not exceed 25% of the rated current.
After the transformer is put into operation, it should be overhauled regularly. In the power supply system of the same transformer, protective grounding and protective zero connection should not be mixed.
The rated voltage of the secondary coil of the voltage transformer is100V, and the secondary side of the voltage transformer should not be short-circuited during operation.
Because of short circuit, it will produce a great short circuit current and burn out the transformer. Therefore, both the primary side and the secondary side of the voltage transformer are equipped with fuses for protection. One end of the secondary side of the voltage transformer is grounded.
This is to prevent the primary high voltage from entering the secondary side when the insulation of the primary and secondary coils is broken down, endangering personal and equipment safety. When the current transformer is working, the secondary side is close to short circuit.
The rated current of the secondary coil is 5A. The secondary side of current transformer is never allowed to be open when working. One end of the secondary side of the current transformer is grounded to prevent the high voltage on the primary side from entering the secondary side when the primary and secondary coils are insulated and broken down. When connecting current transformers, we should pay attention to the polarities of their primary and secondary coils. In China, transformers are labeled with decreasing polarity.
Pay attention to the correct and reliable wiring during installation, and the secondary side is not allowed to be connected with fuses or switches. Even if the instrument or other equipment on the secondary side is to be dismantled for some reason, the secondary side should be short-circuited first and then dismantled.
Low-voltage switch refers to the load under 1KV controlled by low-voltage distribution devices such as disconnectors, circuit breakers and fuses, with clear shunt. It is forbidden to control more than one brake, which is confusing. Interlocking devices for low-voltage power distribution devices and self-provided generator equipment shall be reliable.
It is forbidden to run self-provided power generation equipment in parallel with the power grid privately. Insulating pads should be laid on the channels for front, back, left and right operation and maintenance of low-voltage distribution equipment, and other items are strictly prohibited to be stacked on the channels.
When connecting equipment: connect the equipment first, and then connect the power supply. When disassembling the equipment: first disassemble the power supply and then disassemble the equipment.
When connecting wires: connect the neutral wire first, and then the live wire. When disconnecting the line: disconnect the live line first, and then the neutral line.
Low-voltage fuses cannot protect the motor from overload. The rated voltage of the fuse is greater than or equal to the working voltage of the distribution line.
The rated current of fuse is greater than or equal to the rated current of melt. The breaking capacity of the fuse is greater than the maximum short-circuit current in the distribution line.
The selection of rated melt current can meet the normal working current of the line and the starting current of the motor. For short-circuit protection of electric furnace and lighting load, the rated current of melt is equal to or slightly greater than the rated current of load.
The rated melt current of a single motor is ≥( 1.5-2.5). In the distribution system, the upper and lower levels should coordinate with each other to achieve the purpose of selective protection. The next level should be less than the previous level.
Porcelain plug-in fuses should be installed vertically, and qualified fuses should be used, and other copper wires should not be used instead of fuses. The power inlet of the spiral fuse should be connected to the central terminal of the base, and the outlet of the load should be connected to the terminal of the threaded shell.
When changing the melt, first disconnect the electrical equipment to prevent arcing. Fuses should be installed on each phase line. It is forbidden to install fuses on the neutral line of two-phase three-wire or three-phase four-wire circuits. When the fuse is mainly used as a short-circuit protection fuse for isolation purposes, it should be installed at the head end of the line.
Fuses are used for short circuit protection. Isolate the power supply and maintain safety.
The function of knife switch is to isolate power supply and maintain safety. Rubber porcelain bottom knife switch is the control switch of electric lighting circuit and electric heating circuit, and also the distribution switch of branch. When the capacity is reduced properly, the three-pole rubber cover knife switch can be used to operate the motor control switch occasionally. The power inlet of the three-pole rubber knife switch should be on the inlet seat of the static contact end, and the electrical equipment should be connected to the outlet seat of the fuse below.
When the knife switch is turned off, the handle should be down, and when it is turned on, the handle should be up, and it should not be inverted or pasted. The role of the three-pole rubber knife switch is short-circuit protection. Isolate the power supply and maintain safety.
The shell of low-voltage load switch shall be reliably grounded. When the automatic air switch is selected as the main switch, there are obvious disconnection points on the incoming side of these switches, which can be disconnectors, knife switches or fuses.
The main function of fuse is overload or short circuit protection. Capacitor parallel compensation is to connect the capacitor directly with the compensated equipment in the same loop to improve the power factor.
There are many measures to improve the power factor, among which the most convenient method is parallel compensation capacitor. The wall switch is off the ground 1.3m, the wall socket is off the ground 0.3m, the cable switch is off the ground 2-3m, the watt-hour meter is off the ground 1.4- 1.8m, and the incoming cable is off the ground 2.7m. There should be no joints for first-and second-class highways, trams, major rivers, weak current lines and special ropeways.
Plastic sheath line is mainly used for indoor surface mounting, and shall not be directly buried in the plastering layer for concealed mounting. The total cross-sectional area (insulation layer) of the conductor in the conduit shall not exceed 40% of the cross-sectional area of the inner diameter of the conduit.
There should be no connector for the wires in the pipe, and the connector should be in the junction box; Different power supply circuits, different voltage circuits, mutually standby circuits, working lighting and emergency lighting circuits should not be installed in the same tube. When the pipeline is steel pipe (iron pipe), the wires of the same AC circuit are in the same pipe, and a wire is not allowed to pass through the steel pipe.
There should be no more than 8 wires in a pipe. When the pipeline is steel pipe (iron pipe), the pipeline should be reliably grounded.
When the pipeline is steel pipe (iron pipe), plastic protective sleeves should be added at both ends of the pipeline outlet. When the length of the conductor passing through the pipeline exceeds 30m (semi-rigid pipe), a junction box shall be installed.
When the length of the conductor passing through the pipeline exceeds 40m (iron pipe), a junction box shall be installed. The conductor passes through the pipe, and the length of the bent pipe shall not exceed 20 meters.
It shall be equipped with a junction box. The conductor passes through the pipe, and the length of the two curved conduits is not more than 15m.
It shall be equipped with a junction box. The conductor passes through the pipe, and the length of the three bends is not more than 8m.
It shall be equipped with a junction box. When multi-phase power supply is used, the color selection of conductor insulation layer in the same building should be consistent, that is, the protective conductor (PE) should be green/yellow double-color line, and the neutral conductor (N) should be light blue; The phase lines are L 1- yellow, L2- green and L3- red.
The switch wire of single-phase power supply is red, and white or yellow is used after the switch. The connector of the conductor should not be at the insulator fixing place, and the connector should be 0.5 meters away from the conductor fixing place, so as not to hinder the connection and disconnection.
4. High voltage electrotechnics. What?
1. High-voltage electricians should learn high-voltage courses, power systems and power grids, distribution transformers, transformers, high-voltage electricity and complete sets of devices, relay protection devices in secondary circuits, safety management and operation of substations, and operation and maintenance of high-voltage electrical equipment.
2. Operators of high-voltage electricians engaged in special types of work must be familiar with the corresponding safety knowledge and skills of special types of work to prevent all kinds of accidents. Employees are required to hold relevant certificates (IC cards), that is, the People's Republic of China (PRC) Special Operation Certificate issued by the State Administration of Work Safety. This certificate is used nationwide.
3. High-voltage electrician certificate refers to the operation, maintenance, installation, overhaul, transformation, construction, debugging, test and detection of high-voltage electrical equipment above 1 kv and below1kv.
5. What are the work contents of high-voltage electrician?
1, voltage mutual inductance
2. One end of the secondary side of voltage transformer must be grounded. In order to prevent low-voltage fuses from being used as overload protection for motors.
3. The rated voltage of the fuse must be greater than or equal to the working voltage of the distribution line.
4. The rated current of fuse must be greater than or equal to the rated current of melt.
5. When connecting the current transformer, pay attention to the polarity of its primary and secondary coils. In China, transformers are labeled with decreasing polarity.
6. When installing, be sure to pay attention to the correct and reliable wiring, and the secondary side is not allowed to be connected with fuses or switches.
7. Interlocking devices of low-voltage power distribution devices and self-provided generator equipment shall be reliable.
8, it is strictly prohibited to bring their own power generation equipment and power grid to run in parallel.
9. Insulating mats should be laid on the channels for operation and maintenance of low-voltage distribution equipment, and other items are strictly prohibited on the channels.
10, when the insulation of the secondary coil breaks down, a high voltage rushes into the secondary side, endangering personal and equipment safety.