Many new friends in the electrical industry, the concept of high pressure and low pressure is not very clear, even if it is done for many years of electrical friends, may usually only contact the big family of electrical part of the high and low pressure professional knowledge of the contact is not much, so perhaps in this piece of knowledge is not very systematic. Here to help you comb this knowledge, for your reference.

Let is take a look at what a high-voltage appliance is:

Internationally recognized high and low voltage electrical line AC voltage is 1000V (DC is 1500V). AC 1000V above for high-voltage electrical appliances, 1000V and below for low-voltage electrical appliances. Sometimes the transformer is also included in high-voltage electrical appliances.

When it comes to high-voltage appliances, we have to talk about the "West High". Xi  An institute of High-voltage electrical Appliances in 1958 in the planning of Xi an switch rectifier plant Central laboratory based on the approval of a machine department set up, because the institute at that time clearly for the construction of Xi an switches, electric porcelain, capacitors, insulation and transformers factory to carry out research and development, testing services, involving switches, transformers, protection appliances, measuring electrical appliances and other professional , so named the Institute of High-voltage Electrical Appliances, the name has continued until now.

Let is see what low-voltage electrical appliances are:

Low-voltage electrical apparatus is a kind of component or equipment which can switch, control, protect, detect, transform and adjust the circuit or the non electric object by manual or automatic circuit according to the external signals and

requirements. Control of electrical appliances according to their operating voltage, to AC 1000V, DC 1500V bounded, can be divided into high-voltage control appliances and low-voltage control appliances two categories. In general, Low-voltage electrical appliances can be divided into two categories of electrical distribution and control appliances, is a complete set of electrical equipment components. In the industry, agriculture, transportation, national defense and People is use of electricity, most of the low-voltage power supply, so the quality of electrical components will directly affect the reliability of low-voltage system.

When it comes to low-voltage electrical appliances, you have to say "go to the department". Shanghai Institute of Electrical Science (now called Research Institute) is the National Low-voltage Electrical Standardization Technical Committee secretariat affiliated units. Its authority in the field of low-voltage electrical equipment is self-evident.

Through the above analysis, we must see that the definition of high and low voltage is to Exchange 1000V (DC 1500V) as the boundary, simply say, ac 1000V above is high voltage, 1000V below the low voltage.