Technical Data Sheet: 255-BZZI72-250
Ratings at 2,900 RPM
| Duty | Power | Torque |
|---|---|---|
| Continuous | 20.0 kW | 70.0 Nm |
| 60 minutes | 27.0 kW | 87.6 Nm |
| 15 minutes | 39.8 kW | 133.9 Nm |
Rated current is 250 Arms. Peak output is 43 kW and 189 Nm at 750 Arms.
Specifications
| Model number | 255-BZZI72-250 |
|---|---|
| Frame size | 255 |
| Motor type | PM synchronous, interior magnet |
| Rated voltage | 72 VDC |
| Rated power | 20.0 kW |
| Peak power | 43 kW |
| Rated torque | 70.0 Nm |
| Peak torque | 189 Nm |
| Rated speed | 2,900 RPM |
| Rated / peak current | 250 Arms / 750 Arms |
| Torque constant | 0.28 Nm/Arms |
| Efficiency | Designed for 93% |
| Insulation class | H |
| Protection class | >IP64 |
| Winding material | 100% Copper |
| Magnet | NdFeB |
| Temperature sensor | PT 1000 |
| Bearings | 6008-2Z/C3, 6006-2Z/C3 |
| Cooling | Natural Air Cooled, Forced Air Cool |
| Weight | 67 Kg |
| Mounting | Flange, Foot |
70.0 Nm continuous at 2,900 RPM · 189 Nm peak · 255 frame · interior-magnet rotor
The 255-BZZI72-250 is a 20.0 kW permanent magnet synchronous motor for a 72 V bus, rated 70.0 Nm at 2,900 RPM continuous. It holds 39.8 kW and 133.9 Nm for 15 minutes, and peaks at 43 kW. It weighs 67 Kg and mounts flange, foot.
The rotor is interior-magnet, so it adds reluctance torque to the magnet torque and tolerates field weakening well — it holds useful power further above base speed than a surface-magnet motor of the same frame. Suited to geared traction, blowers and high-speed pump drives, where the reduction stage already exists and a compact motor matters more than shaft torque.
Ratings are published at three duty points rather than one headline figure. Size the motor so its continuous rating covers the average of the duty cycle and its 15-minute rating covers the worst peak — the full 72 V range has 63 models if this one sits slightly wrong.
Quality and compliance
Manufactured at our ISO 9001:2015 certified plant in Faridabad, India. Designed and tested to IEC 60034 — performance and rating to IEC 60034-1, IP64 enclosure to IEC 60034-5, mounting designations to IEC 60034-7, and Class H insulation to IEC 60085.
Every motor is individually tested before dispatch, not batch-sampled: winding resistance, insulation resistance, high-voltage withstand, back-EMF constant, no-load and loaded run, and temperature rise. Test reports are available on request.
Performance Curves
Where this motor is used
- Centrifugal pumps and blowers, where delivered output rises steeply with shaft speed
- Compressor and vacuum pump drives on 72 V mobile and industrial equipment
- Geared traction where the reduction stage already exists
- Light, quick-accelerating axes where motor mass is a design constraint
Applications
Related ratings
Next step down: 255-AHZS72-250 at 20.0 kW, next step up: 360-CZS72-300 at 20.0 kW. Every 72 V model at this rating is compared on the 72V 20kW motors page. See also the 72V motor guide and the full PMSM range from 24 V to 565 V.