Fan speed control generally USES the lower voltage winding and reduces the magnetic field strength to realize speed, now at the task usually adopt method has two kinds, one kind is string into the reactor step-down method as shown in figure TS-1; Another is by change each winding fell circle number, including the lawsuit to tap method is widely used, tap method is through the transformation of each tap position to change each winding circle number, namely his change winding circles of vice tree weakened the magnetic field strength of the stator in order to achieve the purpose of speed.
Tap method speed has three winding methods: 1, the main winding. 2, the intermediate sections. 3, auxiliary winding. Winding up the role of the middle speed, the three winding method can pick up into L respectively and T. One L and divided into L1 and L2 type type two ways, as shown in figure TS-2 shows. L1 type rated voltage is 110 v of the capacitor running type or cover with a motor drive. Because these motors of the middle of the windings and Lord winding in space is in phase with, so two winding distribution in the same slot, among the top of the winding in the windings.
L2 type rated voltage is 220 v of the capacitor running type motor speed. Among them and vice winding between winding in space is in phase with, so two winding distribution in the same slot, among winding in vice winding above.
T tap method is used for the rated voltage is 220 v capacitor running type or cover extremely type motor drive, winding in the Lord among according to deputy winding, but after the phase and the middle winding same winding, two winding in the same slot is distributed, the middle in the Lord above. Winding winding As shown in figure TS-3 shows.