What are the functions of the zero line of the oil-immersed transformer

Oil-immersed transformers have a neutral line that is connected to the working equipment. Because the voltage caused by the operation of the equipment will be transmitted to the oil-immersed transformer along with the cable, so that the oil-immersed transformer will be transported to the power-consuming machinery and equipment. So what about the zero line of the actual oil-immersed transformer?

1. Oil-immersed transformer zero line working circuit

The zero line is mainly used in the working loop. The voltage caused by the zero line is equivalent to the line resistance multiplied by the current of the working loop. Because of the long-distance transmission, the voltage caused by the neutral line cannot be ignored. Ground wire (PE): not used as a working circuit, only as a maintenance wire. Using the absolute "0" voltage of the ground, when the machine and equipment case generates electricity, the current will be quickly injected into the ground. Even if the PE line has a lead, it will be injected into the ground from the surrounding grounding device body.

2. Oil-immersed transformer zero line protective grounding

In fact, the ground wire is not only one kind of grounding protection, but also divided into working grounding and safety factor grounding devices. The working grounding is the grounding wire that uses it to make a loop to make the machine equipment exceed the characteristics specified. For example, in the 1960s and 1970s, the radio programs used in every household in the countryside had a ground wire, and the connection was often wet with tap water. The work grounding is to bury the metal material electrical conductor copper block in the soil layer, and then use a power transmission line to find the road surface, which completes the grounding system. The ground wire specifies that the ground wire resistance is less than or equal to 4Ω. Grounding protection is a safeguard measure used by everyone to avoid accidents when applying electronic products such as household appliances and offices.

The plastic casings of electrical products and office supplies are equipped with grounding wires. If the insulation layer destroys the casing and induces electrification, the current will leak into the ground along the installed grounding wires. The technical specification of electricity consumption requires that the resistance of the maintenance grounding wire should be ≤4Ω, and the resistance of the body generally exceeds 2000Ω. According to Ohm's law, the current flow according to the body when the insulating layer is destroyed is only 1/500 of the total current flow, which has a maintenance effect. .