Dexter Laundry T-750 C4 Installation And Parts & Service Manual page 79

DCS050 Reversing 60Hz. Wiring Schematic
Dryer Idle - No Coins Added:
208/240 VAC 60 Hz power is supplied to the main power terminal block and comes out on BLK/RED and
BLK/BLU wire. 208/240 VAC now passes to the motor control relay (R1) and also passes to the multi-tap
control step-down transformer. The same 208/240 VAC 60hz line voltage will also be supplied to the volt-
age inputs of both variable frequency drives. The control circuit will be powered from the 24 VAC sec-
ondary side of control step-down transformer. Power out of the transformer will travel through the 2.5A
fuse on the black wire for circuit protection. When there is power to the dryer the computer board will be
powered and the display lighted from the 24 VAC secondary side of control step down transformer. 24 VAC
from here is also on one side of the door switches on a black wire. Closing the loading door allows 24 VAC
to pass on to the computer board on two blue wires. One blue wire makes 24 VAC available to one side
of the motor run relay on computer board. The other blue wire provides a 24 VAC signal to the computer
board telling it that the door is closed and door light on the computer board should be illuminated.
Coins Added - Motor Starting and Running:
As each coin is added the coin optical sensor completes the coin drop circuit to the computer board. The
computer board counts these signals and registers them against time. The time will display once the
"START" button and the motor run relay closes on the computer. With this relay closed, 24 VAC passes
through to the red wire and is supplied to the motor control relay (R1), and the drive enable relay (R2),
and also a violet wire going down to the blower motor centrifugal switch. The upper motor LED on the
computer board should be illuminated anytime the computer calls for the motor to operate. With the (R1)
relay engaged and 208/240 VAC passing through to the blower motor start switch, the incoming power
208/240 VAC is supplied directly to the main run winding and through the start capacitor to the auxiliary
winding (start winding). The heat circuit in the dryer cannot operate if the blower motor is not running.
As the motor comes up to speed, the centrifugal switch inside motor opens the circuit to the start wind-
ing and closes the circuit to allow the 24 VAC on the violet wire to pass to through the centrifugal switch
to the other red wire and onto the gas relay on the computer board. At the same time the 24 VAC is sent
out on the red wire from the computer board to the drive enable relay (R2). When engaged, this allows
the DCM common (yellow wire) signal on the drive to pass through to the brown wire MI1 contact on the
variable frequency drive. Completing this circuit engages the drive to send the tumble and reversing volt-
age to the tumbler motor. From the factory, the motor will tumble one direction for 1 minute and then stop
and tumble in the reverse direction for 1 minute. This will continue for the length of the cycle. The time of
the reversing action can be modified by moving the brown jumper wire on the factory default DCM to MI4
connection. Placing the jumper from DCM to:
MCM – Non-reversing
MI2 – 30 seconds
MI4 – 60 seconds
MI5 – 90 seconds
MI6 – 120 seconds
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Part # 8533-120-001 9/21