Dahlander motor
What is a Dahlander motor?
A Dahlander motor is a three-phase induction motor that can run at two speeds by changing how its windings are connected. The high speed is twice the low speed (for example 1500/3000 rpm). At low speed the windings are in delta, at high speed in double star.
Where is a Dahlander motor used?
It is used on two-speed fans and extractors, machine tools, industrial washing machines, hoists and conveyors, wherever two fixed speeds are needed. It is a simple and rugged way to get two speeds without a frequency drive.
Connection and control
All six motor terminals are brought to the panel, with separate contactors for each speed. Low and high speed must never run at the same time, so the contactors are interlocked. Each speed has a different current, so two separate overload relays are used.
What to watch out for
Terminal connections follow the diagram on the nameplate. On first start, check that the motor turns in the same direction at both speeds. Each overload relay is set to the nameplate current for its own speed.
Terminals
Dahlander motor
- Low-speed input
- U1, V1, W1
- High-speed input
- U2, V2, W2
- Earth
- PE
Try it in the simulator.
This component is in CoilPath with its real look. Add it to a circuit, wire it and see how it behaves in the simulation.