Common knowledge on high voltage maintenance

1. Basic knowledge of being a high-voltage electrician

Are you talking about being on duty and doing maintenance at that substation?

Being on duty is very simple, just look at the equipment all day long. If you encounter operations, you have to be careful and ask the unit to prepare insulating gloves and boots. There are some basic rules for operations. For example: it is strictly forbidden to open and close the knife switch while the power is on, the ground knife switch and the main knife switch cannot be closed at the same time, and there are some other things that I will not go into detail.

Maintenance is not difficult. Accidents rarely occur in the power system. Accidents are generally serious (haha, don’t be afraid). If you basically can’t repair it yourself, let your company spend money to find the power supply company. Come and fix it. There are also some basic rules. It is strictly forbidden to open circuit in the second CT, and it is strictly forbidden to short circuit in the second PT. I won’t go into details about others. After all, you didn’t give so many points, haha~

I’ll find some books to read if I have nothing to do. In terms of substation operation and maintenance, maintenance electricians belong to low-voltage electricians and belong to the electricity consumption system, while high-voltage electricians belong to the power supply system. They basically belong to two industries. It is more difficult to supply electricity. It is easier to switch to electricity supply after working in electricity supply. If you switch from electricity use to power supply, you have to enrich yourself. I wish you good luck. What you said above are all correct. Safety first. , leaving green hills without fear of running out of firewood, haha

2. Electrician’s high-voltage knowledge

The five preventions of high-voltage switch cabinets are:

1. Prevent carrying load Opening and closing isolating switch. (The isolating switch cannot be operated when the circuit breaker, load switch, and contactor are closed.)

2. Prevent mis-opening and mis-closing of circuit breakers, load switches, and contactors. (Only when the operating instructions correspond to the operating equipment can *** equipment be operated)

3. Prevent the circuit breaker and load switch from closing when the grounding switch is in the closed position. (Only when the grounding switch is in the open state, the isolating switch can be closed or the handcart can enter the working position, the circuit breaker can be operated, and the load switch can be closed)

4. Prevent the grounding switch from being closed by mistake when it is powered. (Only when the circuit breaker is in the open state can the isolating switch or handcart be operated, the handcart can be retreated from the working position to the test position, and the grounding switch can be closed)

5. Prevent entering the charged room by mistake. (The door can be opened to enter the compartment only when the compartment is not powered)

The four compartments are circuit breaker rooms. Relay room. Cable room. Cable room.

The following steps should be taken for maintenance work during total and partial power outages to ensure safety.

(1) During power outage maintenance work, if the distance between the human body and other live equipment is small, less than 0.35 meters for 10 kV and below, and less than 0.6 meters for 20 to 35 kV, the The equipment should be powered off. If the distance is greater than the above values, but less than 0.7 meters and 1 meter respectively, barriers should be set up, otherwise the power should also be cut off. During a power outage, attention should be paid to cutting off all lines that can deliver power to the maintenance part, and taking measures to prevent mis-closing, and there must be at least one obvious disconnection point at each location. For multi-circuit lines, attention should be paid to preventing sudden calls from other sources, and special attention should be paid to preventing reverse power transmission from low-voltage sources.

(2) Discharge The purpose of discharge is to eliminate residual static electricity on the equipment being repaired. Discharge should use special wires and use insulating rods or switches to operate. Human hands are not allowed to come into contact with the discharge conductor. It should be noted that there should be discharge between lines and ground, and between lines. Capacitors and cables have a lot of residual charge, so it is best to have specialized discharge equipment.

(3) Electricity test Electricity test should be carried out on lines or equipment that have been powered off, regardless of whether the voltmeter or other signals normally connected to them indicate no power. When testing electricity, the corresponding electroscope should be selected according to the voltage level;

(4) Install temporary grounding wires to prevent accidental power transmission and accidental reverse power transmission in the secondary system, and to eliminate other aspects of power failure. To induce electricity, necessary temporary grounding wires should be installed at the outer end of the part to be repaired. The order of installation and disassembly of the temporary grounding wire must not be mistaken. When installing, connect the grounding terminal first, and when disassembling, remove the grounding terminal.

(5) Install shielding. During partial power outage for maintenance, the live parts should be shielded to keep a certain distance between maintenance workers and live conductors.

(6) Hanging signs The purpose of hanging signs is to remind people to pay attention. For example, on a switch that can transmit power to the equipment under maintenance once it is closed, a sign saying "Someone is working, closing is prohibited" should be hung; on a barrier near a live part, a sign saying "Stop, high voltage is dangerous" should be hung. signs, etc.

As for the medium of the vacuum circuit breaker, it is vacuum and there is no other medium. It relies on vacuum arc extinguishing

3. What should you pay attention to when inspecting high-voltage motors

Inspecting high-voltage motors Notes on motors: The performance and lifespan of high-voltage motors depend more on maintenance. Everyone should pay attention to details. The detailed maintenance of high-voltage motors is the beginning of good operation of your equipment.

1: When installing a high-voltage motor, qualified manufacturers should try to put sleeves on the outlet of the high-voltage motor, and clamp the outlet on the edge of the high-voltage motor or equipment, so as to prevent the outlet from vibrating due to the vibration of the equipment. If there is an up and down swing, the outlet wire will be easily worn or the wiring joint will be torn apart. 2: In environments with serious pollution, the bearings should be cleaned regularly and lubricating oil should be added, but it must be high-temperature-resistant lubricating oil. Do not add it every week. If you add it too frequently, the motor will not be able to consume it, and the lubricating oil will flow into the wire package. , it is best to add it once a month, and in a relatively moderate amount.

3: When attachments appear on the surface of the high-voltage motor, clean them in time, because the temperature of the high-voltage motor will be relatively high when it is running, and excessive attachments will affect the heat dissipation of the high-voltage motor. 4: The anchor bolts of high-voltage motors should be checked frequently. If the sliding wire or bolt is found to be loose, it should be dealt with in time.

4. Gaozhuang Electrician Knowledge

During high-voltage maintenance, the procedure of power outage, power inspection, discharge, grounding, tagging and maintenance should be followed.

— "Power failure, power inspection, discharge, grounding, tagging, and maintenance" are safety technical measures to ensure the safety of high-voltage maintenance. Various technical measures should be completed according to the work ticket and operation ticket: During the completion process, There should be supervision; workers should use safety equipment with corresponding voltage levels during operation.

2. During the maintenance work, the equipment under maintenance should have a power outage. When there is a power outage, it should be noted that all power sources that can send power to the maintenance parts should be out of power: During a power outage, the working neutral line in operation should be checked. Live objects, and take the same measures as phase lines; when operating a high-voltage power outage, the circuit breaker should be opened first and then the isolation switch. For example, the power side and load side of the circuit breaker are both equipped with isolation switches. After opening the circuit, , the load side isolating switch should be opened first, and then the power side isolating switch should be opened.

3. For power outage lines or equipment, regardless of whether the frequently connected voltmeter or other signals indicate no power, a power test should be carried out: select the corresponding voltage level according to the voltage level of the power outage line or equipment. An electroscope that has passed the test; before the electricity test, you should check whether the electroscope is in good condition. Only if there is no electricity confirmed by a qualified electroscope can it be used as the basis for no electricity: When testing electricity, you should pay attention to keeping a safe distance to prevent short circuits.

4. When overhauling high-voltage equipment, discharge must be carried out after a power outage; this is mainly to eliminate the remaining charge of the equipment being repaired; the discharge should be performed with an insulated cup equipped with special wires, or with temporary wires. , or operate with a special grounding knife switch. The human body is not allowed to come into contact with live objects during discharge.

5. In order to prevent accidental power transmission to the maintenance part and possible induction of electricity, the outer end of the part to be repaired ( Install a temporary grounding wire on the power outage side of the switch or on the power outage conductor. The temporary grounding wire should ground the three-phase conductors and short-circuit them. When installing temporary grounding wires, the following requirements should be paid attention to: Any equipment that is under maintenance may suddenly receive power. Temporary grounding wires should be hung at appropriate locations on all devices or devices that can generate induced voltages. Temporary grounding wires can only be hung after it is verified that there is no electricity.

Temporary grounding wires should be hung with nine grounding ends (the grounding must be good ), followed by the conductor end of the phase wire, and the disassembly sequence is reversed: the installation and disassembly of the temporary grounding wire should be performed using an insulating rod or wearing insulating gloves, and should be performed by two people.

6. The signs should remind people to pay attention to safety and prevent unsafe behaviors; the signs are mostly made of insulating materials, and there are many types of signs such as "Pedestrians are not allowed to stop due to high voltage", "It is prohibited to close the switch when someone is working", etc. .

5. What kind of knowledge is required for high-voltage electricity?

Let me briefly explain

First of all, you know the basic requirements for the work of some high-voltage equipment, some substations and power generation Safety inspection measures for the factory

Inspection and maintenance work

Management methods for power grid online maintenance

Methods for reactive power management of power grid (standard for measuring a high-voltage electrician)

Basic principles of relay protection devices

Transformer protection repair and maintenance

Microcomputer protection and main backup protection

Differential protection

Automation major

Transportation major

There are many communication majors and there is much to learn. These are for high-voltage electricians on duty

Power system Basic knowledge

Power supply load, power supply quality, substation, grounding, high-voltage complete equipment, high-voltage lines, over-voltage protection, over-current rapid interruption, high-temperature tripping, and the most important thing is electrical safety knowledge, haha< /p>