Turbogenerator Rotor & Exciter Windings

NEC is experienced with the manufacture of turbogenerator rotor windings: copper or aluminum; directly or indirectly cooled.

At our Columbus Rotating Equipment Service Center, we have made a significant investment in design, equipment and process development for our turbogenerator rotor winding manufacturing line. This includes the achievement of ISO 9001:2008 certification for our quality management systems. NEC manufactures windings with either style of end winding corners — square or edge-bent as shown above. Typically, old windings are replaced with new ones of similar design. All brazed joints, whether in the corners or in the arch, are UT tested to prove their durability.

Square Corner EdgeBent Corner
The above photos show examples of corners used for turbogenerator rotor windings at the end turns: a square corner, which is brazed, at the left; the edge-bent, which is shaped in fabrication, at the right.
Below are outlined the typical design options for turbogenerator windings.
  • New or refurbished windings
  • Copper or aluminum
  • Direct or indirect cooling
  • Square or edge-bent end turn corners

Refurbished Rotor Windings

Copper rotor coils

Many successful rotor rewinds are accomplished by refurbishing the existing copper or aluminum conductors. Conductors are cleaned, polished, inspected and tested, and if found suitable, repaired, straightened and re-arched. Should an existing winding prove unsuitable for refurbishment, NEC's Rotating Equipment Service Center can design and manufacture new windings of any type. This includes both solid and ventilated conductors, as well as those with brazed or edge-bent corners. MORE about turbogenerator rotor rewinds.


Exciter Windings

Rewinding Siemens Westinghouse Hydrogen-Cooled Brushless Exciter

NEC manufactures replacement armature coils for rotating exciters, leads and other electrical parts. Whether a complete refurbishment, including rewind, as shown in the picture above, or a maintenance overhaul and cleaning, NEC's goal is to get your machine back in operation expeditiously. MORE about exciter rewinds.

RESC Fully-Equipped for Repairs & Retrofits
NEC's RESC stands ready with the resources to address the known turbogenerator rotor issues, from insulation creepage, ventilation and vibration problems to generic design issues such as rotor tooth-top cracking and pole-to-pole crossovers. MORE
High-Speed Balancing
With peak values of no more than 1 mil, NEC leads the industry in balancing your generator or exciter rotor down to the lowest possible vibration levels. NEC's engineers and skilled technicians also are experienced with all aspects of rotor balancing and testing.
Salient Rotor Poles Windings
NEC's RESC also refurbishes salient rotor poles. Pole windings can be new or refurbished, pole bodies repaired or replaced and connectors repaired or replaced with improved designs. MORE