What is a control device? Answer: It is mainly used to control the switching appliances of the powered equipment and the combination of control, detection, protection and regulation equipment associated with these switching appliances. What is Overcurrent? A: Any electricity that exceeds the rated current. ...

How is an electric current formed? Answer: The free electrons in the conductor move regularly and directionally under the action of the electric field force, and an electric current is formed. What are the indicators of power quality? Answer: Voltage deviation, voltage fluctuation and flicker, voltage sine wave distortion rate, frequency deviation. ...

What are the conditions that must be met for high-voltage appliances? A: A. The insulation is safe and reliable; B. Long-term operation under rated current and certain short-term overload capacity; C. Able to carry the thermal and electrodynamic effects of short-circuit currents without damage; D. Switching electrical appliances can be safe...

What are the basic requirements for a high-voltage circuit breaker? A: A. Reliable work; B. Have sufficient circuit breaking capacity C. Have the shortest possible cut-off time; D. Simple structure and low price. What is the purpose of the disconnector? Answer: A. Electrical...

What is a busbar? Answer: In the voltage distribution devices at all levels of power plants and substations, the wires connecting engines, transformers and various electrical appliances are called busbars. What is the classification of busbars? Answer: soft bus (mostly used in outdoor power distribution room with high voltage) and hard bus (low ...

What is the material of the busbar? A: Copper busbar, aluminum busbar and steel busbar. What is the significance of busbar coloring? Answer: It can increase the radiation capacity, which is conducive to heat dissipation, and the allowable load current can be increased by 12-15% after coloring. ...

What are the main technical parameters of the fuse? Answer: A. Rated voltage, B. Rated current, C. Breaking capacity, D. Melting characteristics, E. Overvoltage. What are the main products of low-voltage power distribution equipment? Answer: Low-voltage distribution panels, switch cabinets, switch boards, lighting boxes, power boxes and electrical ...

What is Peak Load? What is trough load? What is Average Load? A: Peak load refers to the maximum load that can occur on the grid and the user in a day. The trough load is the hourly average of the least amount of usage that occurs in the grid and the users in a single day.

What are the precautions for using current transformers? Answer: 1. The secondary side shall not be open when working; 2. One end of the secondary side must be grounded; 3. The polarity of the terminal should be paid attention to when connecting. What are the precautions for using voltage transformers? A:1. When working, its secondary side shall not be short-circuited ...

What are the principles for drawing and reading the schematic diagram of electrical control circuits? Answer: A. The schematic diagram is generally divided into power supply circuit, main circuit, control circuit, signal circuit and lighting circuit. B. In the schematic diagram, the position of the contacts of each electrical appliance is according to the ...

What are the main differences between electronic control equipment and power distribution equipment products? Answer: The function of electronic control equipment is mainly control, and the function of power distribution equipment is mainly transmission. How much is the external design of domestic electronic control equipment products? Answer: Control panel, control cabinet, control box and console ...

With the continuous improvement of people's living standards, more delicacies continue to flock to the market to satisfy the taste buds of foodies. However, is the food that is about to be delivered to your mouth really healthy? How to ensure the food safety and health of the tip of the tongue without foreign substances? People are concerned about the quality and safety of food production, testing, and safety.

How much is the external design of domestic power distribution equipment products? Answer: Front panel type, cabinet type and box type, but also indoor type, fixed type and component fixed assembly, some products use drawer cabinets. Transmission circuits? Answer: Erected in the power plant step-up substation and ground ...

Power distribution circuits? Answer: From the regional substation to the substation of the electricity unit or the power supply line of the city and township, it is the line used to distribute electric energy. Power lines can be divided into according to the erection method? A: Overhead power lines and cable lines. ...

What is a protective relay? Answer: It can reflect the failure or abnormal operation of electrical equipment in the power system, and act on the device that trips the switch or sends out a signal. What are the commonly used relays? A: Current Relay, Voltage Relay, Signal ...

Indoor unit: suitable for all kinds of control boxes, distribution boxes and electrical cabinets in machinery, electric power, chemical industry, textile machinery, automation equipment, instrumentation and other industries with high requirements for temperature and humidity. It can also be used to regulate temperature and humidity in small spaces. Outdoor unit: suitable for outdoor general base station, outdoor ...

How many types of protection devices are there for transformers? A: Overcurrent protection, current quick break protection, differential protection and gas protection. What are the requirements for relay protection? Answer: In order to be able to remove the fault correctly and quickly, it is required that the relay protection has sufficient selectivity ...

What are the relay protections of small and medium-sized substations? A: A overcurrent protection; B. Current quick-break protection; C. Time-limited current quick break protection; D Low voltage protection. What is the classification of substation monitoring system? A: Manual monitoring, automatic monitoring of telecontrol devices and micro-...

What are the advantages of microcomputer automatic monitoring? Answer: The device is small in size, high in reliability, has the functions of information storage, memory, calculation and logical judgment, and can collect, process, print and display the data. What is overvoltage? Answer: Put the pair of insulated ...

What are the classifications of different electrical experiments according to their roles and requirements? A: It can be divided into insulation test and characteristic test. What are the factors that affect the degree of harm to the human body of electric shock? Answer: The magnitude of the current, the duration of the current, the path of the current, the resistance of the human body, and the ...

What are the types of electric shocks? Answer: Direct electric shock, indirect contact electric shock, induced voltage electric shock, lightning electric shock, electrostatic electric shock. What are the organizational measures to ensure safety when working on electrical equipment? Answer: work ticket system, operation ticket system, inventory site and comprehensive ...