System Elpress terminals and tools

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Soil resistance relation humidity. Soil humidity normal- ly varies between 5-40%. For each case different soil type, soil resistance must measured and prefer- ably during several seasons and differ- ent weather conditions. Measurement ground resistance. great impor- tance that all this taken into account for earth connections earth connection systems. This despite the fact that the use power without, or with poor, earthing incurs great risks. 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. 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. Earthing thus functions as, among other things, personal protection, proper- ty protection, signal transfer protection, lightning protection and the like.75 l. A customer who buys power takes earthing for granted. Current conduction occurs the soil through electrolytic processes, known as ionic conduction. Soil resistance relation temperature. variations below 14-18%, conductivity deteriorates significantly. The water deeper lying ground layers usually has higher salinity than the water the surface layer.g. The connectors are connected verti- cal metal tips that are driven down a row about 0. This means that voltage surges that can occur for various reasons are led into the ground that they not cause dam- age. 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. When calculating approximate earthing resist- ance the earth connection when the depth the resistivity the soil must be measured with electrode distance ≈ 0.clay). Soil conditions external conditions? The importance the soil conductor of electric current great. Measuring earthing resistance the earth connection . Resistivity different soil conditions. 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. Soil with good electrical conductivity thus has low resistivity: 100 Ωm. Weather conditions cold, heat, rain and wind mainly affect the upper layer of the soil 1. Resistivity The electrical properties the soil are quality declared means its resis- tivity, which measured (former unit Ωcm, =100 Ωcm).5 m), which therefore ex- hibits the most powerful variations. (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.3-0. 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.e. Cold (frost) significantly impairs the ground’s conductivity. An approved earthing should have: (1) low electrical resistance, (2) ability to conduct voltage stably (despite weather changes) and (3) long service life, i.5 deep metre apart. good resistance corrosion. Solid particles such as gravel are not usually conductive. All power suppliers must have approved earth connections their installations. The most efficient earthing thus reached when the electrode placed deep enough not affected chang- es soil humidity and temperature