Panel SCCR Rating

I have determined many panel SCCR ratings but I have only had one customer actually specify a minimum panel SCCR rating. How does the end user of the panel know what the minimum panel SCCR rating should be? Is there any sort of guide line to follow?

A minimum SCCR rating has alot to do with what the end user can easily provide for service fault current limiting. The end users existing supply system, including the available fault current upstream of the circuit protection device feeding you equipment, the circuit protection devices used, the existence of isolation transformers and the wire routing and distance to the machine all affect the fault current available to the machine. If you provide the machine with an SCCR greater than this level the end user doesn't need to do anything but hook the machine up and go on their merry way. If your SCCR is lower than the available fault current the end user needs to take action to limit the fault current available to the machine, which can get expensive.

Keith