1 Product model and main technical data The new series of products are named QJZ-mouth Xâ–¡/â–¡ according to the coal system standard, mine flameproof and intrinsically safe vacuum electromagnetic starter or QBZ*OXO/â–¡, mine flameproof vacuum Electromagnetic starter. Its meaning is as follows: The explosion-proof kilovolt explosion-proof electrical products under the mine, on the basis of the original BQD10 series, BQD15 series, through the door opening structure, the use of vacuum appliances, computer comprehensive protection and other measures, the technical level has been greatly improved, some products can also Compared with similar foreign products. Due to the large number of manufacturers, there is a lack of standardization, serialization, and generalization in the industry. Although products of the same specifications and specifications are similar, there are many problems, such as many series, miscellaneous items, and incomplete specifications, which brings about the selection and production management of coal mine users. Some inconvenience.
In response to the above problems, in combination with user requirements, our company carried out a more comprehensive upgrade of the original BQD series products, from the shell structure to the wiring chamber; from the electrical components inside the chamber to the protection plug-in and control circuit, and carried out on the variety specification. In addition, a brand-new kilovolt-class product series with complete specifications and specifications was formed.
Below is a brief introduction to boosting improvements for this series of products.
* Rated voltage I Rated heating current I Ming and intrinsically safe new series of main technical data as shown in Table 1 Table 1 Order rated controlled motor product type Voltage and current maximum power can be seen from Table 1, the new series of products rated The working voltage is 1140V. It can also be used in 660V and 380V power supply systems. The control circuit is intrinsically safe and non-intrinsically safe. The rated heating current is divided into six current classes of 80, 120, 160, 200, 315, and 400A; including 80A. Reversible, 160N reversible, 2X200A dual loop (or reversible), the full range of products a total of 10 specifications, all products have overload, short circuit, broken 2 explosion-proof shell structure characteristics According to the actual needs of users, comprehensive consideration of capacity, price In comparison, the flameproof enclosures used in the upgraded product line are divided into two types: 200A and below are round-type cover-type structures; 200A and above are square-type translation type quick-open door structures, and the two types of profiles are respectively Show.
The round-type cover-type structure is an explosion-proof enclosure that has long been used in coal mines and is still widely used. It can be seen that the new series of enclosures are designed in accordance with the requirements of the kilovolt-class voltage level and intrinsically safe circuit standards. After the modification, the main circuit in the junction box adopts six kilovolt class fork terminal blocks, and at the same time, an insulation baffle is added; the control circuit is changed from the five terminals of the original product to two seven-core terminals, and the distance is greater than 50mm. The number of control cable lead-in devices has also been increased from two to four. This is mainly to meet the needs of the current underground mine control and monitoring, and the rest is the same as the original rotary cover structure products, which will not be repeated here.
It is the outline drawing of a new type of translating quick opening door. The outer shell consists of a main chamber, a connection chamber, a front door and a tray. The shell and door cover adopt a plane stop structure. The wiring chamber is above the main chamber and each is an independent flameproof structure. The right side of the shell is the door cover and the isolation commutation switch interlocking mechanism. The left side of the main cavity is the translating type quick opening door mechanism. This mechanism has greater advantages compared with the lifting quick opening mechanism. It consists of the hinge and the drive shaft. , handle, card board and other components. When opening and closing the door, lift the handle on the drive shaft to the horizontal position, rotate 90* to the left to close the door, and then close the door to rotate and lock the interlock lever forward. When the door is opened and closed, pay attention to the advance and retreat of the interlocking lever. The isolated commutation switch handle is divided into forward, stop, and reverse positions. When the door is opened, the handle must be in the stop position to open the front door.
The housing is equipped with a drawer type body (or vehicle type body), a track and main loop static collision contact, an isolation switch operation board and a control circuit connector, etc. The above two types of flameproof enclosures have been concentrated on mine explosion-proof in recent years. The essence of the design of the shell will become the representative of the switch shell at present and within a certain period of time in China's coal mines.
3 Circuits and Operation Principles and are two typical electrical principles of the new series of products 3.1 Electrical components and circuit characteristics 200A the following products, electrical appliances mainly from the body, the junction box cable into the device, wiring terminals and other components, its main features are: In addition to the voltage upgrade For the 1140V, a switch control circuit with a communication interface for monitoring and monitoring functions is an intrinsically safe circuit that protects the phase-lock, under-voltage, and leakage lockout protection functions.
oumalEleetroniePublish uses a digital motor integrated protector and has a light emitting diode display function to display the operating status of the switch in real time. The load capacity of the main circuit and the accuracy and reliability of control protection are significantly higher than similar products.
1. Insulation board; 2. Unicom section; 3. Fork terminal block; 4. Combined terminal block (seven core terminal sleeve) Road is connected, the main control board through the A2 * terminal for insulation resistance detection, if the insulation resistance is normal ( 1140V, greater than 40k8t660V, greater than 22kQ), the starter can be started. If the insulation resistance is less than the specified value, leakage protection is implemented and the starter cannot start. Only when the insulation resistance returns to normal can it be started.
a. Near-control: Set the remote control button on the control box to the near-control position, press the start button on the front door of the starter, J1 pulls in, J2 releases, J2 - 1 releases, the intermediate relay KA loses power, the relay often The open contact KA1 breaks the leakage detection circuit, and J1 pulls in one, turns on the 36V power supply of the rectifier bridge of the contactor, the pull-in coil gets electricity, the contactor pulls in and the motor starts.
Shown is a schematic diagram of the electrical principle of the 400A starter. The electrical equipment is mainly composed of a vehicle-type push-pull collision body assembly, connection terminals, a collision static contact seat, an output terminal block of the control line in the connection box, a front door stop button, and a test switch without load Etc. The car body is equipped with isolated commutation switch, vacuum contactor, current transformer, RC absorption device, control transformer, intelligent integrated protection device, start button, stop button, reset button, missed test button, over test button, Fuses, collision contacts, connectors for control circuits, and other components. Just screw in or unscrew the screw nut, and at the same time unplug or plug the control cable plug, you can achieve the car body into and out of the housing, use and maintenance is very convenient. The non-loaded test function provided by this switch is an effective means for real-time inspection of the switch on the downhole site and discriminating faults, which can greatly shorten maintenance and repair time, reduce the number of stops (break), and make it convenient for users.
3.2 Operation method and operation principle After upgrading, the series of products have the same electrical principle except for specifications and appearance. Now take the example as an introduction to the starter operation method and operation principle.
The isolated commutation switch QS is placed in the positive or negative position, and the transformer TC1 is controlled to obtain power, which respectively outputs 36V, 24V, 8V, 5V power. At this time, the light emitting diodes of the J2 relay on the main control board light up, indicating that J2 has passed the user alliance 1, the ugly deduction %, the periodical pull-in, the j2 a f normally-open contact suck d the main road load side leakage lock back toe position. 'Woman under the remote control start button can start the same process.
b. Remote control: The remote control button sub-switch on the control box is switched to the normal stop of the remote control stop process. Press the stop button, JI is released, the contactor is disconnected, and the motor stops. J2 pulls in, KA1 gets electricity and pulls, the electric leakage locks the circuit and throws. If the insulation resistance is normal, the starter can be restarted.
Emergency stop, use the stop button on the shell, can directly cut off the contactor coil loop, so that the starter stops running.
Overload and short-circuit protection: During the operation of the starter, the current signal is sent to the main control board D1, D2, D3, D4, D7, D8 terminals through the current transformer TA, after a high-power resistance into a voltage signal, the voltage signal is rectified, Filter, LM358 amplified, sent to the microcontroller. If there is an overload or short-circuit signal, the MCU sends a high level, and after the non-door cuts off the power of the solid state relay J1, the main control board B1 and B2 turn on, and the contactor coil circuit is cut off to stop the starter. "Overload" or "short circuit" is displayed. Only after the fault is cleared, press the reset button to restart.
Phase-failure protection: In the course of operation, when there is a phase loss in the main circuit or a phase disconnection occurs in the sampling circuit, the microcontroller will send a signal after breaking the delay to break the contactor and the motor will stop running. At the same time, the liquid crystal display shows the under-phase “, which owes†the serial number of the broken phase. Only clear the fault, press the reset button before restarting.
Overvoltage protection: During the operation of the starter, the 5V voltage of the secondary side of TC1 is input by the main control board D5 and D6. After being rectified, filtered, and amplified by the LM358, it is sent to the single-chip microcomputer and the liquid crystal display displays the voltage of the system. If the system voltage is higher than 115% Ue, the microcontroller will delay and send a signal to break the contactor and the motor will stop operating. At the same time, the liquid crystal display shows movement.
Undervoltage protection: The action process is the same as above. The liquid crystal display shows 'undervoltage'.
Program-controlled protection: If two or more starters start sequentially, connect the line according to the program control wiring, and dial the code switch on the control box of the starter to the position of program control. The first starter can be controlled near or remotely. The far and near control switches of other starters are switched to the remote control position. After the first start, after a certain delay, the next start, if the next one does not start, then the previous single-chip sent a signal, J1 release, program-controlled start failed. At the same time, the liquid crystal display shows program control. To restart, the reset button must be pressed.
4 Conclusion The QBZ and QJZ series starters introduced in this article are used in the underground coal exchange AC 50Hz, rated working voltage 660V, 1140V power supply system to start and stop the control of 9560kW mine flameproof squirrel cage asynchronous motors. Run, formed a full range of products from the 80A400A. Moreover, the used shells are unified into two forms of two squares and two rounds, which are convenient for the management of coal mines. Its electrical operation principle and operation requirements are roughly the same. The main electrical components have a high standardization procedure. The installation layout is more focused on the user's use and maintenance and will certainly be the first choice for coal mines in the future.
(Continued from page 42) Complete, abundant data acquisition information, and adopted a variety of analysis and troubleshooting methods. The analysis software is developed in the VC environment and has a friendly interface that facilitates secondary development to extend the richer diagnostic capabilities.
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