Blower Motor: Description and Operation

Operation





Ventilation fan motor 36 has three speeds and is controlled from fan selector switch 35.

Switch 35 is supplied from fuse 9, via the 29-pole red connector 152B. The fan speed can be varied by taking the supply from different points on resistor 74.

When main fan switch 149 is closed, the fan will always be running, regardless of the position of the fan selector switch.

Main switch 149 and AC switch 150 are controlled by the air distribution control. Switch 149 is closed when the control is in any position except position 0, when it is open (control closed). Switch 150 is closed when the control is in position < - >. The fan motor will then receive the full supply and run at the highest speed.

If resistor 74 is overloaded, the resulting heat will cause the bimetal switch to close. The positive supply will be earthed, and fuse 9 will blow. The bimetal switch will open when it has cooled.