Are inspections required for grounding?
Hello!
Are there any NFPA requirements for inspecting grounding bus to ensure the grounding is adequate?
NFPA 77 says if the system is all metal, resistance in continuous ground path typically is less than 10 ohms.
Does this need periodically tested?
Comments (5)
This is a damn good question. Standing by for someone smarter than me to answer
I always had my maintenance team check the OHMS annual at my facilities. However, one area was Class 1 Div 1 and the other area had Class 1 Div 1 specific areas in it.
So, this is not a regulation, but it is important to read the manufacturer specs and recommendations. The NEC and NFPA have regs on proper installment. That being said, I think some people do inspections for a best practice. I am not sure how frequency is determined other than a risk assessment. Interested to see if anyone has any other references
We inspect are annually , do to the fact we have a dust program and PSM Facility.
Annually is recommended for grounding. I think off hand you are looking for <.4 ohms. However, if this is a grounding bus than typically you would have the bonding lines from that. These along with any connections (clamps, connectors, cords, etc.) must be inspected daily prior to use and annually checked for resistance. On bonding your ohms should be rated to Minimum ignition. Typicality <5 to prevent any general sparking discharge.