Equipment ground connection testing

[parlitu]

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.

 

[7anoter4]

In my opinion, nor NEC[NFPA 70] neither IEEE-142 requires such test.
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