Generator Rotor Resources Under One Roof

Manufacturing at NEC's Columbus, Ohio facility supports its projects for the maintenance, repair and retrofit work for turbogenerator and salient pole rotors, whether it is rotor windings or various components.

Columbus is a 265,000 square foot facility employing about 300 associates (three shifts) housing the company headquarters and NEC's Rotating Equipment Service Facility.. This facility focuses on the repair, refurbishment and upgrade of large rotating electrical equipment.

This location is also the management base for company-wide services for NEC's Technical Services Group, Project Management Group and Customer Service, as well as various business operations departments.

Physical Profile

• Five large service bays and additional flex space
• Cranes: 30-, 50- and 85-tons (100-ton one-time pick capacity)
• High Speed Balancing: in-ground bunker with Schenck Balancer; dynamic stand driven by a 4000 HP DC motor. Rotors up to 200,000 pounds and up to 94 inches in diameter and 42 feet between bearing centers can be accommodated at speeds up to 4000 RPM. Seismic pick-up includes IRD Mechanalysis, and a proximity probe can be obtained on special request.
• Facilities for various cleaning methods: degreasing, steam-detergent, steam water, corn cob grit, sand blasting, glass beads.
• Arc Welding: Electrode, MIG, TIG, and Heliarc
• Brazing: Oxy-Acetylenr, Resistance, Tong 50 KVA
• Spray Welding: Eutectic Powder, Flame Spray, Rototec
• Plating: Chrome – In-house
• Lathes (Maximum Size): 70” swing x 53’ length
• Line Boring (Maximum Size): 5” bar x 60” vert. x 72” x 72”
• Coupling/Rotor Stack Pullers: Any size – can be done in-house
• Press: 600 ton
• Ovens: extendible, with precision temperature thermocouples, gas recirculating and Asbestos Burn Out, 12’ x 12’ x 28’ long

In-House Testing Capabilities & Equipment

• Full and Partial Voltage Runs
• Megger
• Polarization Index
• Dielectric Absorption
• AC and DC High Potential
• Winding Resistance, Double Bridge or Biddle Ducter
• Current Balance
• Surge Comparison
• Growler
• IR (Volt Drop) for Field Coils
• RSO Tester
• Flux Probe
• Current Dip: Rotor Bars
• Core Loss, Loop Test Method and “El Cid”
• Wet Test Winding
• Dimensional Tolerances
• Bearing Clearances
• Air Gap
• Vibration; Three Plane IRD

Inspection & Testing Services

NEC's Inspection & Testing Services are available to owner's needing specialists to supplement their own workforce during outages or to assist them in troubleshooting a machine failure. Depending on the specific project's needs, these services may be provided by technicians of our Generator Services Group in conjunction with engineers from our Technical Services Group. Read more about Failure Modes and our services for Inspections & Testing.

Capabilities for Major Overhauls

Major generator overhaul projects may require rewinds of generator stators and rotors to run on parallel schedules. Because of the unique manufacturing and capabilities found at each of its factory sites, NEC can easily support projects of this complexity.

Project Management

NEC's Project Management Group provides comprehensive coordination necessary for the most complex projects. As the owner's primary contact throughout the project, our project managers keep their eyes on project schedules and budgets, interfacing with NEC's manufacturing and service units, as well as key interfaces with other contractors and sub-contractors at the owner's site.