 鲜花( 30)  鸡蛋( 0)
|
Earth Ground Testing
) m* b, X |; ^/ O4 k, C* n# |( u7 i/ M, Z
Most 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.
' _# S/ w+ m# m4 }! {- U) d
0 t* g7 B( @8 u: [1 P% ~/ }) A5 f2 tUnderstand 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. |
|