Patents Represented by Law Firm Bradley, James E.
  • Patent number: 4901070
    Abstract: An electric submersible pump system has a pressure monitoring device for monitoring the pressure down the hole. The pressure monitoring device has a pressure transducer whose resistance varies with the pressure. The pressure transducer is connected to ground and is supplied with a DC current that is superimposed on the AC power cable. A temperature switch is connected between the pressure transducer and the motor winding. The temperature switch is normally open, and closes when it reaches a selected temperature. The temperature is selected to be above the ambient temperature in the well and below the temperature that occurs when the motor is operating and fully warmed up. The temperature switch isolates the windings from ground when the motor is shut off and cooled down. This enables the motor winding and power cable to be checked for insulation resistance.
    Type: Grant
    Filed: July 25, 1989
    Date of Patent: February 13, 1990
    Assignee: Baker Hughes Incorporated
    Inventor: Joseph E. Vandevier