TECO-Westinghouse, Toshiba, Nidec and GE Motors

Short answer

TECO-Westinghouse, Toshiba, Nidec (US Motors) and GE make low- and medium-voltage induction motors of NEMA and IEC design, widely installed in pumping, compression, mining and process plants across the Americas. This guide summarizes which lines each manufacturer has, what is checked on a medium-voltage motor and how it is protected and integrated into the plant control system.

What it is and where it is used

TECO-Westinghouse, Toshiba, Nidec and GE motors are induction motors, and also synchronous ones, found in pumping stations, compressors, induced-draft fans, mills and conveyors in mining, cement plants and process plants across the Americas. They are of NEMA or IEC design and cover everything from low voltage to medium voltage, which is where a motor stops being a consumable and becomes an asset that is tested, protected and monitored.

Each manufacturer has its own history. TECO-Westinghouse presents itself as a manufacturer of motors and generators, motor controls and original Westinghouse spare parts, and repairs large motors. Toshiba sells its motors in the Americas through Toshiba International Corporation, which states that it builds them in Houston. Nidec Motor Corporation, of the Nidec group, groups brands such as US Motors, Leroy-Somer and Control Techniques. GE’s large motors continue at GE Vernova (Power Conversion), whose center for medium- and high-power induction and synchronous motors is in Campinas, Brazil. HD Hyundai Electric motors are also found.

For the operating principle and the protection of this type of machine, see induction motor and its protection.

Variants: TECO-Westinghouse, Toshiba, Nidec, GE and Hyundai

Manufacturer	Lines it publishes	Typical application
TECO-Westinghouse	Low- and medium-voltage motors, generators; identified by designations such as MAX-E and ODP on the nameplate	Pumping, oil and gas, heavy industry
Toshiba (Toshiba International Corporation)	LV: Severe Duty, 841, Explosion Proof, IEC. MV: Weather-Protected Type I and II, ODP, TEFC, TEAAC, TEWAC, wound rotor and synchronous	Water, mining, oil, processes
Nidec Motor Corporation (US Motors)	NEMA, IEC, Large AC, vertical, Severe Duty, hazardous locations, inverter duty	Vertical pumps, HVAC, industry
GE Vernova	Medium- and high-power induction and synchronous motors	Compression, generation, processes
HD Hyundai Electric	Industrial induction motors	Industry and process plants

The exact designation of a motor is on its nameplate: voltage, power, poles, service factor, frame type and insulation class. With it, the correct data sheet and manual are found.

Main characteristics

Enclosure and cooling: open drip-proof (ODP), weather-protected (WP I and WP II) or totally enclosed fan cooled (TEFC), with an air-to-air (TEAAC) or air-to-water (TEWAC) heat exchanger. The cooling defines where it can be installed and what maintenance it needs.
Rotor: squirrel cage in most; wound rotor and synchronous motors for heavy starts or reactive power control.
Supply: direct-on-line start, soft starter or variable speed drive; with a drive, the insulation and the bearings must be prepared for it.
Protection accessories: temperature detectors (RTD) in the windings and bearings, anti-condensation heaters and, in large machines, vibration sensors.

What GE Vernova and Toshiba publish

GE Vernova (Power Conversion, Campinas, Brazil). Its manufacturing capability brochure (June 2024) describes the Campinas plant as a center of excellence in medium- and high-power induction and synchronous machines. It was founded in 1962 and has produced more than 12,000 induction machines and more than 500 synchronous ones. For medium- and high-power induction motors (NMP/NHP) it lists IEC frames 400 to 1120 (NEMA 580 and larger), 2 to 24 poles, and 50 and 60 Hz or drive operation. Cooling is IC411, IC01, IC611 and IC81W in IEC, and WP I-II, TEFC, TEAAC and TEWAC in NEMA. Power ratings run from 1 to 20 MW and voltages reach 13.8 kV. Among the synchronous and induction motor platforms it lists C7, Custom 8000, Pegasus, HS9000, LS9000 and Quadramatic. For the synchronous machines it mentions laminated or solid salient-pole rotors. Starting can be direct asynchronous, with reactor, capacitor or autotransformer, with a pony motor or with an electronic soft starter, or the motor can be suitable for drive operation. High-speed synchronous generators and condensers appear with VPI insulation.

Toshiba International Corporation. Its motors and drives page organizes the offering into general-purpose and definite-purpose low voltage, open and enclosed medium voltage, wound rotor and synchronous. In open medium voltage it lists Weather-Protected Type II and Type I and ODP; in enclosed, TEFC, Totally Enclosed 840 and 841, the 587 high-torque frame, TEAAC and TEWAC. The page also states that motors, drives and panels built in Houston can be tested together.

Those designations help in reading a nameplate or an offer. WP I and WP II are open with weather protection (type II with baffled air paths that limit the entry of rain and particles). TEAAC and TEWAC are enclosed with an internal air-to-air or water-to-air heat exchanger. TEFC is enclosed with an external fan. Each limits where it can be installed and how it is maintained.

Standards that apply to these motors

NEMA MG 1 (motors and generators) for the North American market and IEC 60034 for the rest; in large medium-voltage motors the project specifications often also invoke API 541 (oil and gas) or IEEE 841 (severe-duty process industry).
IEEE 112 for the performance testing of polyphase induction motors.
IEEE 43 for insulation resistance. In practice, minimums are cited that depend on the age and construction of the winding. For old or field-wound windings, the rule is “rated kV plus 1 MΩ”. For modern form-wound coils, values of the order of 100 MΩ are cited, and for random-wound windings, 5 MΩ. All are corrected to 40 °C, and a polarization index of 2.0 serves as a reference for good condition. The specific motor is judged with its history, not only with the minimum.
NEMA MG 1, parts 30 and 31 define the voltage stress limits for general-purpose and definite-purpose motors fed by a drive. A motor bought for direct-on-line starting must not be assumed suitable for a drive.

How to read its situation by brand

TECO-Westinghouse. Many units installed in the region carry the original Westinghouse nameplate. The corporation states that it offers original Westinghouse spare parts and repair of large motors; for the age and exact series, the nameplate rules.
Toshiba. The nameplate identifies the frame type (WP, TEFC, TEAAC, etc.) and with it the applicable manual; open-type medium-voltage units require cleaning and inspection of their air paths, something enclosed ones do not need.
Nidec and US Motors. They are brands of the same corporation. In vertical pump motors, the allowable axial thrust and the type of upper bearing are on the nameplate and are not inferred from the size.
GE. Motors of the historical lines remain in service with the support of GE Vernova; in synchronous motors, the excitation system and its protection are part of the asset and must be tested together with the motor.

Points of attention in testing and maintenance

Open and weather-protected motors. Contamination and humidity in the cooling air directly affect the insulation; the trend of insulation tests over time says more than a single measurement.
Synchronous motors. In addition to the stator, the field, the excitation system and the rotating diodes, if any, are tested.
Repair and rewinding. After a repair, the acceptance tests must be repeated and compared with the factory ones or the previous ones.
Soft starter start. If you plan to change from direct-on-line starting to a soft starter, see soft starter and starting large motors and voltage drop.

Communications and integration

A motor does not communicate by itself: its motor protection relay, the drive or the starter does. The relay measures current and voltage, reads the RTDs and delivers alarms, trips and the thermal image to the control system and the SCADA, over Modbus, DNP3 or IEC 61850 depending on the device. See motor protection relay and, for large motors, motor differential protection 87M.

Frequently asked technical questions

Manuals for medium-voltage TECO-Westinghouse and Toshiba motors: each manufacturer publishes installation and maintenance manuals by line; the correct one depends on the frame and cooling shown on the nameplate.
Nidec Motor Corporation and US Motors: they are the same organization; US Motors is one of the brands of Nidec Motor Corporation.
The motor trips on starting: it is usually the starting current against the relay setting, a strong voltage dip or an insulation fault. We cover it in overcurrent trip on starting or energization.
Low insulation after a long shutdown: moisture is the most common cause; that is why medium-voltage motors carry heaters. The insulation resistance and polarization index test says whether it can be energized.

How we help

We do not sell or repair motors. At Tiza Group we test medium-voltage motors of any brand (insulation, polarization index, windings, surge and thermography), verify their protection and support commissioning, in substations and in industry, in Colombia or elsewhere on request. See motor testing within testing and commissioning. Write to us through the contact page.

References

IEEE 43, insulation resistance of rotating machines; NEMA MG 1, motors and generators; IEC 60034, rotating electrical machines.
Toshiba International Corporation, motors and drives; Nidec Motor Corporation, AC motors; GE Vernova Power Conversion, Campinas rotating machines; TECO-Westinghouse, corporate site.

Frequently asked questions

What types of medium-voltage motor does Toshiba offer?

Toshiba International Corporation publishes open medium-voltage motors (Weather-Protected Type I and Type II, Open Drip-Proof) and enclosed ones (Totally Enclosed Fan Cooled, Totally Enclosed Air-to-Air Cooled and Totally Enclosed Water-to-Air Cooled), plus wound-rotor and synchronous motors. The nameplate and the data sheet give the voltage, power and cooling type of each unit.

Which brands does Nidec Motor Corporation group?

Nidec Motor Corporation, part of the Japanese Nidec group, presents US Motors, Leroy-Somer and Control Techniques among its brands. In AC motors it publishes NEMA, IEC, large AC, vertical, hazardous-location and inverter-duty lines.

What tests are run on a medium-voltage TECO-Westinghouse or Toshiba motor?

Those of any medium-voltage motor: insulation resistance and polarization index, winding resistance and turn-to-turn surge test; as complementary tests, insulation power factor and thermography in operation. They are interpreted against the nameplate, the equipment history and the applicable IEEE and IEC standards.