System voltages and fault currents determined easily on D-C board

G. W. Hampe (Commonwealth Edison Company, Chicago, Ill.): Mr. Asbury has pointed out some uses of the d-c calculating board which generally are not recognized. Apparently, Mr. Asbury left the matter of reading the residual currents directly in amperes, that is, with one board milli-ampere representing, say, ten line amperes, as distinct from reading unit currents on a given kilovolt-ampere base, up to the reader´s discretion. The use of unit currents is common for three-phase faults.