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

Shunuo varistor / ESD varistor / comprehensive product line / Sunlord's official agent

Probe current voltage pin, 420*4450 head diameter 5.0, overcurrent and voltage pin specification

Brand AVX TPSE226M035R0125, low impedance tantalum capacitor, AVX 22 series

SMD aluminum electrolytic capacitor for high stability and long life applications

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

1. It is essential to ensure continuous electrical conduction between the equipment and the grounding body or between the equipment and the neutral point of the transformer’s low-voltage side. Any disconnection must be avoided. Natural and artificial grounding bodies should be reliably connected. When welding grounding devices, the lap length for flat steel should be twice its width, with at least three edges welded. For round steel, the lap length should be six times its diameter. If other connection methods are used, good contact must be ensured, and the grounding resistance value must meet the required standards.

2. Grounding bodies should be made of galvanized steel components, and welds should be coated with asphalt oil to protect exposed parts from corrosion. In highly corrosive soils, copper or galvanized materials should be used instead, with an increased cross-sectional area to ensure sufficient mechanical strength and corrosion resistance.

3. When connecting to a protective earth (PE) system, the neutral wire must have sufficient conductivity to allow the protection device to operate quickly in case of a short circuit. The conductivity of the PE wire should not be less than half that of the phase conductor. In systems with large ground currents, the thermal stability of the grounding system must be checked during single-phase grounding events.

4. The distance between the grounding body and the building should be no less than 1.5 meters, and the distance between the grounding body and the independent lightning rod should be at least 3 meters. To improve reliability, the working, protective, and lightning protection grounding branches of electrical equipment should be separately connected to the main grounding trunk or body, with at least two connection points.

Additionally, the upper end of the grounding body should generally be buried at a depth of no less than 0.6 meters, below the frost line. The grounding or earthing wire should be installed in a location that is not easily accessible to prevent accidental damage, but it should be clearly marked for easy inspection and maintenance.