Inspection and operation of high and low voltage electrical equipment and devices of power fittings:

What is the function principle of high voltage fuse in the circuit?

The breaker is the protection element of the circuit or equipment, which is used for short circuit and overload protection of small load distribution lines and distribution transformers.

When the short-circuit current flows through the breaker, the thermal element itself is heated and fused, thereby cutting off the circuit to achieve the purpose of protection.

What are the characteristics of the spring operating mechanism?

Compared with the electromagnetic operating mechanism, the elastic operating mechanism is characterized by the realization of AC operation without complex DC equipment, which provides conditions for simplifying the equipment, so it is widely used.

What is the function of the power hardware isolating switch?

The main function of the isolating switch is to isolate the power supply, which is convenient for maintenance and switching the power supply. It has no arc extinguishing device and can only turn on and off a small current without breaking the load current. This switch has an obvious disconnection point and sufficient insulation capacity to ensure the safety of personnel and equipment.

What is the difference between on-load voltage regulation and no-load voltage regulation?

No-load voltage regulation needs power failure to be carried out, and the voltage regulation range is small. Although the power transmission time is reduced, it cannot meet the requirements of special power consumption.

on-load voltage regulation can automatically adjust the voltage according to the voltage change of the power grid, without power failure, and is suitable for the power demand of special customers.

What is the purpose of the short-circuit test for the transformer?

The purpose of the short-circuit test for the transformer is to measure the copper loss of the transformer. During the test, short-circuit the low-voltage winding, and add voltage to the high-voltage side to make the current reach the rated value. At this time, the copper loss of the transformer is equivalent to the copper loss of the rated load. The voltage applied on the primary side is called the short-circuit voltage of the transformer, and the percentage of the ratio of the rated voltage is the impedance voltage of the transformer.