Abstract: An electric driven hydraulic fracking system is disclosed. A pump configuration that includes the single VFD, the single shaft electric motor, and the single hydraulic pump that is mounted on the single pump trailer. A pump configuration includes a single VFD configuration, the single shaft electric motor, and the single shaft hydraulic pump mounted on the single pump trailer. The single VFD configuration converts the electric power at the power generation voltage level distributed from the power distribution trailer to a VFD voltage level and drives the single shaft electric motor to control the operation of the single shaft electric motor and the single hydraulic pump. The VFD voltage level is a voltage level that is required to drive the single shaft electric motor. The VFD configuration also controls operation of the auxiliary systems based on the electric power at the auxiliary voltage level.

Abstract: An apparatus for determining the length of wires includes connector assemblies, a current source circuit, a voltage gain circuit, analog-to-digital converter, a read-only memory, a microprocessor and a display unit. The connector assemblies are connected across the ends of the wire whose length is to be determined. The current source circuit is used to selectively supply different values of currents to the wire whose length is to be determined. The voltage gain circuit is responsive to the different values of currents for selectively generating a plurality of different voltage levels for each of the different values of currents so as to provide an analog voltage signal having a predetermined range. The analog-to-digital converter is responsive to the analog voltage signal for converting the same to a first digital signal corresponding to a resistance of the wire.