The grounding resistance tester초고압 전력을 사용하면 많은 전력 작업자가 다양한 전력 테스트를 더욱 편리하게 수행할 수 있습니다.
Types of grounding devices and grounding reference resistance values
The electrical installation technical standards specify the following types of grounding installations and grounding resistance values * 1:
Grounding installation grounding resistance value
Class A (formerly Class 1) 10 Ω or less
Class B (formerly Class 2) calculated value * 2
Class C (old level 3) 10 Ω or lower * 3
D-level (old level 3) 100 Ω or lower * 3
*1 lists the values of a certain standard.
Please note that these values vary by country/region.
*2 The ohm value is equal to the ground fault current (ampere) of a wire in the high voltage side or extra high voltage side circuit of a transformer divided by 150 (or, if the voltage of the low voltage circuit exceeds 150 V due to the combination of the low voltage side circuit of the transformer and the high voltage side circuit of the [a] transformer or the extra high voltage side circuit of the [b] transformer, and the voltage used is 35000 V or lower, according to [1] 300, if equipped with a device that automatically shuts down high voltage circuits or special high voltage circuits with a service voltage of 35000 V or lower for more than 1 second but less than 2 seconds, or [2] 600, if equipped with a device that automatically shuts down high voltage circuits or special high voltage circuits with a service voltage of 35000 V in less than 1 second).
*3 If equipped with a device that automatically shuts off the relevant low-voltage circuit within 0.5 seconds in the event of a ground fault, it is 500 Ω.
