National Electric Coil

Company Details       

Point of Contact

National Electric Coil        

800 King Avenue
Columbus, Ohio 43212
United States
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Howard Moudy
Director of Service Management

P: 614-488-1151
M: 724-787-4967
F: 614-488-8892

About NEC

National Electric Coil is the leading independent manufacturer of high-voltage generator stator windings with expertise in design and manufacturing for stator windings for any size, make or type of generator. This includes diamond coils, Roebel bars, including direct cooled, inner-gas and inner-liquid cooled bars, and wave windings. Manufacturing capabilities also include the turbogenerator rotor windings of all types and ventilation schemes. NEC’s windings are manufactured under ISO9001-certified quality management systems, and the company is the largest independent winding manufacturer for generator stator and rotor windings.

NEC is also a leader in the maintenance, repair and upgrading of air- and hydrogen-cooled generators. In addition to stator and rotor rewinds, related services include testing, condition assessments, failure analysis, and engineering design.

Products and Services

Specification Sheets

Rotor Rewinds
Generator Life Extension 
J-strap Failures
Pole-to-Pole Connectors
Exciter Inspection and Testing
Core Integrity Testing
Spark Erosion
Inspection & Testing Services
Stator Inspection & Testing
Emergency Response

NEC’s Service Facility in Columbus, Ohio, offers a full line of products and services for turbogenerator rotors, which includes a high-speed balance pit equipped to address a full range of running and overspeed, electrical and mechanical testing. The Service Facility also is equipped to make all types of rotor repairs and upgrades, as well as the repair and refurbishment of exciters and salient rotor poles.

NEC’s staff of design engineers are experts in addressing a wide range of generic design issues in response to issues raised in OEM TILs and OMMs, as well as designing machine modifications to improve the unit’s efficiency, reliability and maintainability. Examples include pole-to-pole crossover and connection repairs for turbogenerator rotors.

In addition to on-site generator stator rewinds, NEC’s Generator Field Services provides a number of related services ranging from stator rewedging to a wide range of repairs and modifications to both generator stators and the rotors.

NEC also offers generator owners a wide range of Inspect and Test (I&T) options. Owners may wish to assure the continued reliable operation of a machine or diagnose a suspected problem during a planned outage, or they may need expertise to help analyze the evidence of failure during a forced outage. The state of the machine at the time of inspection and testing will drive the extent and type of data that can be collected. Additionally, some types of rotor inspections and tests are better accomplished using equipment and resources available at NEC’s Service facility in Columbus, Ohio. NEC has I&T programs to address any combination of needs.

Areas of Expertise

Gas Turbines

Steam Turbines

Repairs and rewinds

Repairs and rewinds



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