I /'. COMPARISONS WITH SUB-STATION FIELDS
The breakdown of the gas gap, due to the high voltage impulse, is assumcd to occur at about 80 kV in the worst case. Using the equivalent circuit for the Marx generator the maximum current is therefore calculated to be 28 A. Knowing the maximum current at the point of breakdown for the Murx generator ancl the bus cui‘rent for a 115 kV substation, it is possible to make some comparisons of their respective measurements. Measurements made at 2.25 in in a substation [7] with a peak current of 400A indicate 'electric fields in