A great tool for electrical engineers and electricians.
This app will calculate a fault:
Over a line
Through a XFMR
The bracing de-rate factor for a utility XR ratio.
Where length is inputted you can use your GPS from your phone to get an approximate distance (only as accurate as the GPS in your phone).
The calculations use the 2008/2011/2014 National Electric Code (NEC)
See the About menu for additional functions
Get this app plus Voltage Drop, Wire Ampacity and Box/Conduit fill with Electric Pro
v2.1 - Updated to add NEC 2014