Use of Surge protector

Surge, also known as surge, as the name suggests, is an instantaneous overvoltage that exceeds the normal operating voltage. Essentially, a surge is a strong pulse that occurs only in a few millionths of a second. Possible reasons for surge generation include bulky equipment, short circuits, power switching, or large engines. Products with surge blocking devices can effectively absorb sudden and huge energy, protecting connected equipment from damage. Surge protector, also known as lightning arrester, is an electronic device that provides safety protection for various electronic equipment, instruments and communication lines. When a sudden peak current or voltage occurs in the circuit or communication line due to external interference, the Surge protector can shunt in a very short time, so as to avoid the damage of surge to other DC Surge protector devices in the circuit. The graded protection of Surge protector (also called surge arrester) needs to release the lightning energy to the ground gradually through graded discharge because of the huge lightning energy. The first level lightning arrester can release direct lightning current or the enormous energy transmitted by transmission lines when subjected to direct lightning strikes. For places that may be directly struck by lightning, primary lightning protection must be implemented. The second lightning arrester is a protective device for the residual voltage of the previous lightning arrester and induced lightning strikes in the area. After the energy of the previous lightning stroke is absorbed, there is still a large part of energy for the device or the third arrester. The DC Surge protector needs to be further absorbed by the second arrester. At the same time, the transmission line through a lightning protection device will also induce lightning Electromagnetic pulse radiation LEMP. When the line is long enough, the induced lightning energy will become large enough, so the second lightning protection device needs to further release the lightning energy. The third lightning protection device protects LEMP and the remaining lightning energy passing through the second lightning protection device. The length of the connection should be as short as possible. One of the essence of device protection is to ensure that the high voltage of the circuit is less than the high withstand voltage of the device. The protection level of surge protectors needs to be selected according to the specific protected equipment. One rule to observe is that the wiring length from the grounding terminal of the surge protector to its protective circuit breaker (fuse) shall not exceed 50 cm, and the feeder of the DC Surge protector standby equipment to be protected must be correctly connected with the surge protector terminal and the protective circuit breaker terminal. The phase line, zero line and ground wire must be closely connected to reduce the surface area of the circuit. The wiring of the incoming and outgoing lines of the Surge protector must be independent of each other to reduce the interference to the protected line. The cables must be laid flat on the metal frame of the distribution cabinet to reduce the circulation of the frame and enhance the effectiveness of shielding interference. If the protected load is particularly sensitive to overvoltage, but the distribution box is made of plastic, the plastic distribution box must be replaced with a metal distribution box. In any case, it is necessary to check whether the metal frame of the distribution cabinet is grounded through a short circuit. Finally, if shielded cables are used, invalid additional cable lengths must be removed, otherwise the shielding effect will be reduced.

March 8, 2023

Special Type of Self resetting Undervoltage Protector

When the single-phase line is under voltage, the line will be cut off and the single-phase line voltage will return to normal. After a delay, the line will automatically reset and connect without the need for manual operation. 2. When transient or transient overvoltage occurs on the line, the protector will not cause misoperation. 3. When the voltage of the circuit is unstable due to faults such as accidental contact, or when there is a sudden power outage or incoming call, the protector will not connect the circuit. When the circuit fault voltage is high, the protector itself will not be damaged. 5. The protector is characterized by inverse time action, with an action time of ≤ 1s. 6. Voltage protection range: 0~450V below 40A, 0~600V for 50/60A. 7. Impulse withstand voltage: 4kV (in accordance with Class III electrical safety standards). 8. The protector has a dual color LED indicating the working status, green indicating normal voltage, and red indicating undervoltage or delay. 9. Modular design of appearance and installation of guide rails. 10. Wiring capacity: Insulated wires of 25mm2 and below.

March 8, 2023

The difference between soft starter and frequency converter

Soft starter and frequency converter are two widely used devices in the field of industrial control. The following will explain the differences between soft starter and frequency converter: 1. The control principles of soft starter and frequency converter are different. Soft starter is actually an excessive control device, which is an industrial control product between the star triangle starting device and frequency converter. Its functions are more than the star triangle starting device, but less than the frequency converter. From the perspective of the main circuit of the soft starter, it is a three-phase anti parallel thyristor connected in series between the power supply and the controlled motor. Then, the internal digital circuit controls the moment when the thyristor conducts within a complete sine waveform of AC power. If the thyristor is allowed to conduct at the beginning of an AC cycle, the output voltage of the soft starter is high. If the thyristor is allowed to conduct at a certain position in an AC cycle, So the voltage output by the soft starter is low. We use this method to gradually increase the voltage at the motor end during the starting process, thereby controlling the starting current and torque of the motor to achieve a smooth start. It can be seen that the soft starter can only change the voltage of the power supply, not the frequency of the power supply. The principle of the frequency converter is relatively complicated. Its function is to change the power supply with voltage of 380V/220V and frequency of 50HZ into an AC power conversion device with adjustable voltage and frequency. The torque and speed of the AC motor can be adjusted by adjusting the frequency and voltage of the power supply. We can see from the main circuit that its main circuit is composed of another six Field-effect transistor, Under the precise control of the control circuit, six field-effect transistors are turned on in turn. The more times the tubes are turned on per unit time, the higher the output voltage and frequency. Therefore, this main circuit is controlled by a digital control circuit to achieve frequency regulation and voltage regulation of the output power supply. 2. The purpose of soft starters and frequency converters is different. The main problem that soft starters solve is to reduce the starting current of large loads and reduce the impact on the power grid. The startup of large equipment will generate a very large starting current, which will cause a significant voltage drop. If traditional step-down methods such as star delta are used, it will not only cause a significant current impact on the power grid, but also cause a significant mechanical impact on the load. In this case, a soft starter is often used for startup to achieve a smooth start of the motor and reduce the power supply capacity. The frequency converter is mainly used in places with speed regulation. It can control the speed of three-phase motors. For example, the frequency converter can be used in the speed regulation of spindle motors of CNC machine tools, the transmission control of mechanical conveyor belts, large fans, and applications of heavy machinery. In general, its function and practicability are far greater than those of soft starters The control function of the frequency converter of the soft starter is different. The main function of the soft starter is to adjust the starting voltage of the motor, achieve smooth starting of the motor, and reduce the impact of the motor on the machinery and power grid. However, because it controls the voltage by controlling the conduction angle for chopping, and the output is an incomplete sine wave, this leads to low starting torque, high noise, and high harmonics, which can pollute the power grid. Although the soft starter also has various functions such as limited current function setting and startup time setting

March 8, 2023

Ten Characteristics of Self Composite Undervoltage Protector

When the single-phase line is under voltage, cut off the line and the single-phase line voltage returns to normal. After a delay, the line will automatically reset and connect without the need for manual operation. 2. When transient or transient overvoltage occurs on the line, the protector will not cause misoperation. 3. When the voltage of the circuit is unstable due to faults such as accidental contact, or when there is a sudden power outage or incoming call, the protector will not connect the circuit. When the circuit fault voltage is high, the protector itself will not be damaged. 5. The protector is characterized by inverse time action, with an action time of ≤ 1s. 6. Voltage protection range: 0~450V below 40A, 0~600V for 50/60A. 7. Impulse withstand voltage: 4kV (in accordance with Class III electrical safety standards). 8. The protector has a dual color LED indicating the working status, green indicating normal voltage, and red indicating undervoltage or delay. 9. Modular design of appearance and installation of guide rails. 10. Wiring capacity: Insulated wires of 25mm2 and below.

March 8, 2023

About Surge protector

Surge protector is also called power supply lightning arrester (or high-voltage lightning arrester) SPD. 50/60 is applicable to communication AC HZ, and the rated current is up to 380V. In the power supply and distribution system (or communication system), the Surge protector used for power supply lightning protection becomes the power supply Surge protector, which is divided into primary power supply Surge protector, secondary power supply Surge protector, tertiary power supply Surge protector and fourth power supply Surge protector according to the level of its protective power source. 1. The current carrying capacity is different. Generally speaking, the level of overcurrent in the first level is much higher than that in the second level. The first level is mainly used for drainage pipelines, and the second level is mainly used for pressure limiting. After the first level drainage pipeline, the current value significantly decreases after the second level pressure limiting. The primary power Surge protector has a large current carrying capacity, and the discharge current is 100-200kA. The voltage protection level is 1800-2000 kV. The discharge current of the secondary power Surge protector is 40-80kA, and the working voltage protection level is lower than 25000 kV. 2. The protection effect of the primary power Surge protector is different. It is mainly used for lightning current relief. The products are mostly voltage switch type 10/350 μ S-wave pattern; The important role of secondary power Surge protector is to limit overvoltage, and the product is 8/20 μ S-wave pattern. 3. The product form is different. The first level power surge is divided into power lightning protection box (B+C box type linkage, first level power lightning protection box, first level power lightning protection control module), and the second level power Surge protector is usually the power lightning protection control module. 4. The installation methods are also different. Generally speaking, the first level of Three-phase electric power incoming distribution cabinet is installed in a house, and then the second level is assembled on each floor. The primary power lightning protection box is installed at the entrance of the building, outdoor large and medium-sized key equipment power supply, weak current machine room, etc; The primary power Surge protector is the main distribution box of the building and the internal structure of the distribution box of the outdoor machinery and equipment with large power. The secondary power Surge protector is assembled in the distribution box of outdoor incoming and outgoing line input.

March 8, 2023

Introduction to the functions of fire inspection cabinets

The fire patrol inspection cabinet is a kind of equipment with high Factor of safety, low electric flow and low power consumption, which is favored by many different industries. In addition, this equipment also has many different functions. For this matter, the general functions of its equipment will be introduced in detail below. 1. Inspection function: Fully automatic low-speed inspection of fire pumps is carried out one by one according to the established cycle time. Generally, the rotation speed ratio of each centrifugal water pump during inspection is 300 revolutions per minute, and the inspection operation time is 10 minutes; (The duration and cycle time can be set as needed) and can be manually and automatically switched according to the power switch to complete the inspection. 2. The function of fully automatic withdrawal from inspection and entering into fire safety: The inspection cabinet automatically withdraws from inspection and enters into fire safety operation when encountering fire safety data signals during the entire inspection process. 3. Alarm and maintenance functions: The inspection cabinet also has alarm and maintenance functions for short circuit faults, overcurrent, motor power off, and other faults. During the entire inspection process, faults are detected and sound and light alarm data signals are sent out. The alarm equipment has fault memory function, recording the specific content and duration of the fault. Fire inspection cabinet 4. Remote control monitoring and operation function: The inspection cabinet can be equipped with remote control and controller according to the customer's requirements. According to the system bus and fire safety control center communication, it can achieve the goal of operating the fire safety control center monitoring system. 5. Pressure water supply function: The inspection cabinet can also carry out pressure water supply for the pipeline system software based on the configuration of the fire pipeline. Equipment for pressure water supply inspection should be selected, and the pipeline should have anti overpressure measures. Equipment should be installed to inspect and release pressure control circuits, and the circuit settings should be reliable. 6. Alarm SMS function on mobile phones: According to the customer's needs, the inspection cabinet can also be equipped with a SMS alarm module. When a fault occurs, the fault information content is sent to the customer's mobile phone based on the SMS message, reminding the customer to handle it properly. The above six points are a detailed introduction to the common functions of fire inspection cabinets. Based on their detailed introduction, customers can have a clearer understanding of the application of the equipment, thereby reducing equipment application failures and reasonably increasing its service life.

March 8, 2023