Busbar faults

[dfdt]

We have a legacy practice of not allowing peeople to enter live switch yard if busbar protection is out of service and wonder what is your experience or practice in this regards?
thanks for your input in advance

 

[stevenal]

Moving about the yard is not generally considered to be interacting with the circuit in a way to generate an arc flash.
If you are interacting with the circuit, you need to perform an arc flash study or use the NESC tables to determine the incident energy and appropriate PPE. At these voltages the fault current is likely to be low and the separation distance large making the IE low. Consider the effect of reclosing as well.

 

[davidbeach]

Stuff happens. Any time, for any reason or seemingly no reason at all. Stuff that happens in the station with nobody present can just as easily happen as you walk by.

 

[stevenal]

I agree that stuff happens at any time. However, when dealing with arc flash, the 1st assumption is that the arc you are protecting against is human initiated. This is to avoid attempting to protect against every unreasonably low probability event that could possibly occur.
The NESC refers to "employees who work on or near energized lines, parts or equipment." OSHA uses similar language.
Moving about the yard normally would not be a concern. Moving about the yard carrying a long object would be. Moving about the yard to a position close to where another is working on a live circuit would be a concern as well.