rayporter
Electrical
- May 20, 2016
- 2
I'm trying to calculate the available fault current for a 3-phase service. It's easy if the utility transformer is a conventional 3-phase XFMR, but I'm not sure what to do when it's three single-phase XFMRS.
I've seen it before, but in this case we have one 75kVA (2% Z) and two 37.5kVA (1.7% Z) transformers (delta configuration). I could use the largest value and calculate worst case available fault current, but is that really physically possible if the other two phases can't allow that much energy through? Will I be sizing equipment incorrectly?
Any suggestions would be helpful.
Thank you.
I've seen it before, but in this case we have one 75kVA (2% Z) and two 37.5kVA (1.7% Z) transformers (delta configuration). I could use the largest value and calculate worst case available fault current, but is that really physically possible if the other two phases can't allow that much energy through? Will I be sizing equipment incorrectly?
Any suggestions would be helpful.
Thank you.