Recent content by matt111111

I have determined that the data sent to me was based on the 12.5 kv side of the transformer. Is there any way to determine what the fault current rating is on the 600v side if the transformer impedance is unknown?

Double checked with the utility they have stated that the fault current is: 5224A three phase and 4524A line to ground fault. I have used these parameters in the modeling software I am using and they have returned the results of 5.425 MVA sc and 4.697 MVA sc.

sorry 5.425 MVA sc 4.697 MVA sc

I got the info from the utility which was stated as 5.425 MVA sc L-L-L 3.744 MVA sc L-G Xl/Rl 3.74 X0/R0 3.63 These are the ratings at the main. From the main it then feeds into a distribution panel and on the panel is one 400A breaker that feeds the building in question. If I did know the...

The sub building I'm looking at has a main breaker with a rating of 400A at 600v. Would I be safe to say the short circuit current is the breaker maximum of 400A? and if so then I could just assume the short circuit MVA rating for the building would be = (sqrt 3 * 600v * 400A)/6

I am trying to determine what the 3 phase and 1 phase MVA short circuit rating is for my shop. Do I need to request this information from my utiliy provider or is there another way of determining this? Also if the utility enters a main building and that main building supplies multiple...

"Maybe you need to have separate secondary busses for the transformers, then have very low impedance connections from those busses to the common secondary bus. " I tried this out but still seems to give the looped condition

Is it not possible to supply two tranformers in parrallel from a panel using two different breakers? My set up works fine when I supply the parallel transformers directly from the utility but when I supply them through the panel I get the error saying a loop condition has been detected

I have not modified the tap positions of the transformers. I have left them as there default values of 0 % tap on both the primary and secondary

Both transformers have the std positive seq, -30 degree secondary phase shift

Hi I am trying to connect two transformers in parallel using the electrical modeling program ETAP but I keep getting an error: A loop condition has been detected for Panel2 and its downstream elements. I assume this means there's a ciculating current ?!?

antigfk's how expirenced are you with ETAP I just began using it and have a few questions any help would be great!

I am doing a coop term that requires me to do an electrical analysis of a machine shop. I have been given limited instruction with this project. I have decided to start with a fault current analysis and continue to a power flow analysis. I am having problems with collecting the information...