When Progress Energy’s Robinson Plant in Hartsville, South Carolina needed two 4,000 volt pump motors refurbished, the best choice for the job was none other than 3-D Service. With a scheduled refueling outage planned for the nuclear plant, 3-D Service was given a four week window in which to complete the mammoth-sized motors.

The first motor to arrive was a 1,750 HP, 43,000 pound circulating water pump motor. The motor was sent prior to the scheduled outage to allow Progress Energy to address pump problems at the power plant. As part of the refurbishment, 3-D Service manufactured a new coupling, rebabbitted the bearings, repaired the shaft, and rewound the stator. The stator was vacuum pressure impregnated (VPI) twice with an additional epoxy overcoat. VPI was chosen because it provides sealing, electrical insulation, and mechanical support of the windings.

The second motor to arrive was a 3,000 HP, 17,500 pound condensate pump motor. In addition to manufacturing a coupling, rebabbitting the bearing, and rewinding the stator, 3-D Service welded and machined both ends of the shaft. Progress Energy welding engineer Greg Bice was called in to oversee our welder, Frank Jones, while he performed the repairs. Bice was impressed with Jones’ overall welding process and complimented him on his work. After the repaired shaft was installed, the rotor was balanced. The stator was also vacuum pressure impregnated (VPI) twice with an additional epoxy overcoat.

Henry Pollock, Senior Engineer and Technical Support Specialist from Progress Energy, made a three day visit to witness assembly and final testing, which included high potential testing at 9,000 volts AC. Additional testing included insulation resistance, a surge test to IEEE standards, mechanical vibration testing to ISO 1940/1 standards, and monitoring temperature rise in the bearings and stator windings during the final run test. The final run test for the 1,750 HP motor was completed at 4,000 volts at a duration of 5-½ hours. The 222 RPM rating on this unit required a longer run time to achieve stable temperatures. The 3,000 HP unit achieved stable temperatures after a 2-½ hour run at 4,000 volts since it has a 1,200 RPM rating. Both units shipped as scheduled to allow for installation prior to completion of the outage. For a complete overview of 3-D Service’s generating station services, click here.