Resistance is often omitted when making fault calculations, even in
computer programs. Of course, omission of resistance introduces some error,
but the results may be satisfactory since the inductive reactance of a system is
much larger than its resistance. Resistance and inductive reactance do not add
directly, and impedance is not far different from the inductive reactance if the
resistance is small . Loads which do not involve rotating machinery have little
effect on the total line current during a fault and are usua lly omitted. Synchronous
motor loads, however, are a lways in cluded in making fault calculations