System Elpress terminals and tools

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Kroužkové, vidličkové a kolíkové konektory Elpress ...

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great impor- tance that all this taken into account for earth connections earth connection systems. Solid particles such as gravel are not usually conductive. Resistivity The electrical properties the soil are quality declared means its resis- tivity, which measured (former unit Ωcm, =100 Ωcm). By increasing distance the current penetrates deeper into the ground and the measured resistivity can fall in- crease depending the resistivity the ground layer metre’s depth. The techni- cal specifications and requirements for earthing demonstrate the advantages of deep-earth connections, both techni- cal and economic solution, relation to surface-earth connections. Current conduction occurs the soil through electrolytic processes, known as ionic conduction. The most efficient earthing thus reached when the electrode placed deep enough not affected chang- es soil humidity and temperature. Soil resistance relation humidity.3-0. Soil conditions external conditions? The importance the soil conductor of electric current great. Measurement ground resistance.5 m), which therefore ex- hibits the most powerful variations. This despite the fact that the use power without, or with poor, earthing incurs great risks.75 l. For each case different soil type, soil resistance must measured and prefer- ably during several seasons and differ- ent weather conditions. The connectors are connected verti- cal metal tips that are driven down a row about 0. The water deeper lying ground layers usually has higher salinity than the water the surface layer. Measuring earthing resistance the earth connection . The higher the moisture content the soil, the better the conductivity.11:8 System structure and function deep earthing Earthing An earth connection conductor placed the soil, with the aim divert- ing electrical current from installation connected the earth connection and into the surrounding soil.e. Earthing thus functions as, among other things, personal protection, proper- ty protection, signal transfer protection, lightning protection and the like. (See image) If the instrument reading the resis- tivity the soil calculated according to the following equation: p Ωm In unlayered soil, resistivity inde- pendent the electrode distance a. This means that voltage surges that can occur for various reasons are led into the ground that they not cause dam- age.5 deep metre apart. Cold (frost) significantly impairs the ground’s conductivity. measurement today almost exclusively voltage compen- sated electronic resistance bridges are used (measurement method according to Wenner) with connection contacts, of which are for current electrodes and for voltage probes.g. The electrical conductivity the soil therefore mainly depends the propor- tion saline water bound capillary forces and osmotic pressure the pores between grains sand and hygroscop- ic humus particles (e. good resistance corrosion. A customer who buys power takes earthing for granted. variations below 14-18%, conductivity deteriorates significantly. An approved earthing should have: (1) low electrical resistance, (2) ability to conduct voltage stably (despite weather changes) and (3) long service life, i. Soil resistance relation temperature.clay). Resistivity different soil conditions. Soil humidity normal- ly varies between 5-40%. All power suppliers must have approved earth connections their installations. When calculating approximate earthing resist- ance the earth connection when the depth the resistivity the soil must be measured with electrode distance ≈ 0. Weather conditions cold, heat, rain and wind mainly affect the upper layer of the soil 1. Soil with good electrical conductivity thus has low resistivity: 100 Ωm