Equipment ground connection testing
Equipment ground connection testing
(OP)
Does anyone now if there is any Standard, that required equipment grounding connection testing (resistance measurement) from equipment to the ground grid? Or a visual inspection is enough? I dont find any requirements in NFPa70. Not sure if resistance measurement from equipment (motor, switchgear etc) the the ground grid is necessary.






RE: Equipment ground connection testing
It is considered if using approved appurtenance as per NEC 250.8 article it is safe enough. Other national standard requires such a test. For instance:
See BS 7430/2011:
10.4.2 Routine maintenance/examination
2) Joints. A resistance measurement should be taken across all exposed accessible joints/connections using a micro-ohmmeter. The value should be compared with Table 14. Any joint where the resistance value is excessive should be broken down, cleaned and remade or replaced