ronlow00 wrote:
I am currently working on a project for a 480Y/277V system. The electric utility has given me their information. Included in this information is the type of fuses they use at their transformer. Now if I include the utility transformer fusing information in my study, the Arc Fault hazard is greatly reduced in the system I'm studying. However, the utility warns that their information and the fusing may change without notice. So, what is everyone's thoughts on including the utility transformer fusing in the system study. I believe since it is part of the system it should be included, but I question it a bit since it can change without notice. any thoughts?
If you didn't include the utility fusing information, what clears a fault on the source side of your first OCPD? I would say use the information on the existing protection.
As others have said, periodically review the data. Also, if you observe the utility replacing their equipment, ask for new information.