การทดสอบประสิทธิภาพของอุปกรณ์ป้องกันฟ้าผ่าการทดสอบการตอบสนองต่ออิมพัลส์ฟ้าผ่าของระบบรากสายดิน

Abstract

In this paper presents the lightning response testing of grounding system by considering the type of soil to effect of grounding resistance. In this grounding resistance test at power frequency will measure using the 3-point method and impulse grounding resistance using impulse tester. From testing results found that in the case of soil resistivity value, less than 100 ohm-meter, the grounding resistance values at the power frequency are less than the impulse grounding resistance, AC imp R R and the impulse coefficient of the soil, is more than 1. While in the case of soil resistivity value, more than 100 ohm-meter, the grounding resistance values at the power frequency are more than the impulse grounding resistance, AC imp R R and the impulse coefficient of the soil value, is less than 1. Therefore, the grounding system design should be known the soil resistivity value, then the impulse coefficient or ratio of grounding resistance at power frequency and impulse grounding resistance can be found. If any resistance is greater than that, take that resistance to further design a grounding system later.