21-FII medium-voltage induction motor, TEFC, up to 6.6 kV, 37–1400 kW
Three-phase induction motors of the 21-FII series in totally enclosed fan-cooled (TEFC) design rated 37–1400 kW. This item covers voltages up to 6.6 kV, IEC frames 250–500, 50 or 60 Hz and degrees of protection IP44–IP55. Used in pumps, fans, compressors, conveyors and crushers.
- Power
- 37–1400 kW (50–1850 hp)
- Number of poles
- 2–10 (2 poles up to frame 400)
- Frames (IEC)
- 250–500
- Design
- TEFC (totally enclosed fan-cooled), finned cast iron frame
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The 21-FII series are three-phase low- and medium-voltage induction motors in totally enclosed fan-cooled (TEFC) design based on IEC frame sizes. This item covers the medium-voltage versions up to 6.6 kV, while the low-voltage versions of the same series are presented separately. Series power is 37–1400 kW (50–1850 hp), the number of poles is from 2 to 10, and two-pole motors are made only up to frame 400. IEC frames are 250–500, frequency 50 or 60 Hz.
The rotor with a cast aluminium cage of extended application withstands frequent starts and has a small moment of inertia. The cast iron frame with improved finning and better ventilation increases efficiency and output in the frame size. For the 6 kV class, separate terminal box sizes are provided. The main terminal box is on top and rotates through 90°, and on request it is fitted at an angle for side cable entry.
The bearing assemblies have been redesigned, and the lubrication interval is doubled compared with previous designs. Grease is added on the running motor through grease nipples on the side, and the used grease collects in a quick-release cassette.
Three-dimensional analysis of heat conduction and the magnetic field has improved the efficiency and rated output of each frame size. As a result the motor is more compact than its counterparts, easier to transport and install, and has low noise and vibration. The class F insulation system gives mechanical rigidity and winding durability, and the series is compatible with frequency converters.
The motors are manufactured under ISO 9001 and ISO 14001, hold third-party certificates (Lloyd's, Baseefa, CSA and others) and comply with IEC, NEMA, BS and AS. Degree of protection is IP44–IP55. Mounting dimensions are standardized to IEC, shafts and keys to JIS. Voltage in this item is 3.3–6.6 kV (400 V to 6.6 kV across the series), 50/60 Hz. The series is designed for frequent starts and long operation without frequent bearing maintenance. The motors drive pumps, fans, compressors, conveyors and crushers in the oil and gas, chemical and mining industries, at water utilities and at power plants.
Technical specifications
| Power | 37–1400 kW (50–1850 hp) |
|---|---|
| Number of poles | 2–10 (2 poles up to frame 400) |
| Frames (IEC) | 250–500 |
| Design | TEFC (totally enclosed fan-cooled), finned cast iron frame |
| Degree of protection | IP44–IP55 |
| Rotor | cast aluminium cage |
| Thermal class | F |
| Standards and certificates | IEC, NEMA, BS, AS; ISO 9001/14001; Lloyd's, Baseefa, CSA |
| Voltage | 3.3–6.6 kV (series: 400 V – 6.6 kV), 50/60 Hz |
Request a price and lead time
21-FII medium-voltage induction motor, TEFC, up to 6.6 kV, 37–1400 kW. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
What are the power and voltage of the motors in this item?
Series power is 37–1400 kW (50–1850 hp), and in this item voltage is 3.3–6.6 kV. Across the series the range is from 400 V to 6.6 kV.
Which frames and numbers of poles are available?
IEC frames from 250 to 500, number of poles from 2 to 10. Two-pole versions are available only up to frame 400.
What are the degree of protection and insulation class?
Degree of protection IP44–IP55, class F insulation. The motors comply with IEC, NEMA, BS and AS and hold Lloyd's, Baseefa and CSA certificates.
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