Special products · twee toerentallen in één motor
Pole-changing motors, two speeds, one motor
For fans, pumps, mixers and crane drives that need two different speeds. Dahlander or separate-winding configuration. 0.18-55 kW, IEC frame 71-250.
Power range
0,18-55 kW
IEC Frame
71-250
Speed ratio
1:2 or 1:1.5
Lead time
4-6 weeks
Principle · Dahlander switching
One winding, two speeds.
By switching the pole sets between series and parallel, the number of magnetic poles changes, and with it the synchronous speed. No VFD required. No extra windings.
01 · High
Parallel switching
Pole pairs in parallel: half the magnetic poles, double the speed. Typically 2:1 ratio.
02 · Switch
Contactor / star-delta
Two contactors swap the winding between series and parallel. Star-delta start built in.
03 · Low
Series switching
Poles in series: full pole count active, half speed. Full torque, no loss.
04 · Benefit
No VFD
Mechanically robust. No EMC filters, no drive electronics, no harmonics. Low-maintenance in harsh conditions.
Applications
When a pole-changing motor?
A pole-changing motor has two different synchronous speeds, activated by switching between pole sets. Ideal where a VFD is too costly or technically undesirable:
- Fans, low speed for base load, high for peak demand (energy saving)
- Pumps, base load + peak load without VFD
- Mixers in chemical processes, pre-mix + main-mix
- Crane drives, approach speed (precise) + travel speed (fast)
- Takels, fijnpositionering + transportstand
- Compressoren met variabele luchtbehoefte
Configurations
Dahlander vs. separate winding
Two fundamentally different designs, each with its own speed ratio and torque characteristic:
Dahlander winding
One winding, 4/2-pole or 8/4-pole. Speed ratio always 1:2. Constant torque or constant power. More compact and cheaper.
Separate windings
Two physical windings on one stator. Free choice of speed ratio (1:1.5, 1:3 etc.). More flexibility, higher motor cost.
| Power range | 0.18 kW, 55 kW |
| Frame | IEC 71 to 250 |
| Voltage (Dahlander) | 400V Y/YY configuration |
| Speed ratio | 1:2 (Dahlander) · Free (separate) |
| Pole combinations | 4/2 · 6/4 · 8/4 · 8/6 |
| IP class | IP55 standard · higher on request |
| Thermal protection | PTC or PT100 |
Delivery
Lead time and advice
Build-to-spec
4-6 weeks
Custom from factory
Pole-changing motors are almost always build-to-spec. We build on your exact speed ratio, power and connection type.
Alternative
1-3 b. days
IE3 motor + VFD from stock
Sometimes cheaper and more flexible than pole-changing. We advise the best solution for your application and budget.
View standard product list
6,800+ electric motors, Dormot and ABB, filterable by power, frame and specs
Contact
No-obligation technical advice
Send us your desired speeds, load profile and application. We compare pole-changing vs. VFD on engineering and TCO and advise the best choice for your situation.