Safety requirements for grounding and zeroing - Solutions - Huaqiang Electronic Network

Shunuo varistor / ESD varistor / product complete / Sunlord first-class agent

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

Brand AVX TPSE226M035R0125 Low impedance tantalum capacitor AVX 22

SMD aluminum electrolytic capacitor

TP-IP4220CZ6 5V 0.35PF breakdown voltage 6V SOT

1. It is necessary to ensure the continuity of electrical conduction between the electrical equipment to the grounding body or between the electrical equipment and the neutral point of the low voltage side of the transformer. There must be no disconnection. The natural grounding body and the artificial grounding body must be connected reliably. When welding between grounding devices, the length of the flat steel lap welding shall be twice the width and welded at least at the edges of 3, and the length of the round iron lap welding shall be 6 times its diameter. When connecting by other means, it must be ensured that the contact is good, and the grounding resistance value should meet the requirements of the regulations.

2. The grounding body should be made of steel galvanized components, and the welding should be coated with asphalt oil to expose the ground part of the paint. In highly corrosive soils, grounding bodies made of copper or galvanized components should be used and the cross-sectional area should be appropriately increased to ensure sufficient mechanical strength and corrosion resistance of the grounding body.

3. When the protection is connected to zero, the neutral wire should have sufficient conductivity to enable the protection device to operate quickly in the event of a short circuit. The conductivity of the protection neutral wire should not be low without using the natural conductor as the neutral wire. One-half of the phase line. The grounding device of the large ground current system should check the thermal stability when single-phase grounding occurs.

4. The distance between the grounding body and the building should not be less than 1.5 meters, and the distance between the grounding body and the grounding body of the independent lightning rod should not be less than 3 meters. In order to improve the reliability of the grounding, the working grounding, protective grounding and lightning protection grounding branch (or zero-branched branch) of the electrical equipment should be connected to the grounding trunk or grounding body separately. There should be two connection points.

In addition, the buried depth of the upper end of the grounding body is generally not less than 0.6 m, and is below the frozen soil layer. The grounding wire or the zeroing wire should be installed in a place that is not easily accessible to people to avoid accidental damage, but it must be obvious and easy to check and maintain.