American Dryer Corp. AD-200 Clothes Dryer User Manual


 
69
4. Blower Motor Circiut
IMPORTANT: The L.E.D. indicator on the computer board that reads "DOOR" must be on in
order to successfully troubleshoot the following.
Theory of the Blower Motor Circuit:
The Blower (squirrel cage fan) Motor converts the 3-phase (3ø) power source entering the Blower Motor
thermal magnetic overload. The overload current is adjustable by a dial located on the face of the overload.
(Refer to the electric specification diagram for correct setting.) The voltage is then supplied to the top half
(L1,L2, and L3) of the blower (squirrel cage fan) contactor. Providing the 24 A/C volts for the "DOOR" input to
the computer is present on pin #5 of the 15 pin computer harness the computer is going to output that 24 volts on
pin #5 upon the start of a cycle which will in turn travel through a couple of connectors and land on the A1
marking of the blower and fan contactor. This will shut closed sending the three phase voltage to the overload.
Providing the overload is not tripped, the voltage will then travel to the blower and fan motor.
Path of Voltage for the Blower/Fan Motor Circuit:
Three phase voltage is applied to the power distribution block each line L1, L2, and L3 . The voltage then
travels to the Blower (squirrel cage fan) thermal magnetic overload. The voltage is then supplied to the blower
and squirrel cage contactor marked L1, L2 and L3. As long as the fuses overload is not tripped 208-600 volts
will always be there at the contactor. When the computer calls for the fan to come on, 24 A/C volts will output
of pin #5 of the computer. This 24 A/C volts will pass through J1 and J3 connectors pin #5 on both, and travel
to the coil of the blower (squirrel cage fan) contactor, the contactor will be marked A1. The other side of the coil
A2 will be directly grounded. When the 24 A/C volts reaches the coil, the contactor closes and the incoming
voltage that is supplied to the top of the contactor L1, L2, and L3 meets the T1, T2, and T3 of the contactor
which then must go through the overload. If this overload is tripped (i.e. "DOOR") the voltage will stop here and
not proceed to the blower (squirrel cage fan) motor. If the overload is not tripped the voltage will then proceed
down to the blower (squirrel cage fan) motor.