鲜花( 30) 鸡蛋( 0)
|
Earth Ground Testing
' ~7 _ e) U# l+ G+ `0 |6 I
+ S! b& j+ N' _% p! I5 DMost facilities have grounded electrical systems, so that in the event of a lightning strike or utility over voltage, current will find a safe path to earth. A ground electrode provides the contact between the electrical system and the earth. To ensure a reliable connection to earth, electrical codes, engineering standards, and local standards often specify a minimum impedance for the ground electrode. The International Electrical Testing Association specifies ground electrode testing every three years for a system in good condition with average up-time requirements.
) x& D: M( o( E9 a- ~7 R2 B) e9 r
7 f6 n8 c5 T+ i7 rUnderstand earth/ground principles and safety in more depth and then describes the principle testing methods: 3 and 4 pole Fall-of-Potential testing, selective testing, stakeless testing and 2 pole testing. |
|