GE DCB330EY, Technical Service Manual

Page: 13 / 42

12
Door Switch
The door switch is a normally open switch wired in
series with the drive motor. When the door is closed
and the motor running, a circuit is completed through
the motor’s run winding. To test the switch, remove
the top panel and wires from the switch. When the
door is closed, the switch should read continuity.
When the door is open, the switch should read open.
To replace the switch, squeeze the retaining clips
together and pull the switch from the front of the
dryer.
Control Thermostat and Bias Heater
The control thermostat regulates the temperature
inside the dryer drum. It is a single pole, single throw
switch wired in series with the high limit (or safety)
thermostat and the heat source. It is mounted on
the front of the blower housing. The control
thermostat also contains a bias heater. The purpose
of the bias heater is to apply a small amount of heat
to the control thermostat when the fabric selector
switch is set to the medium temperature setting. This
small amount of heat causes the thermostat to open
sooner to maintain a lower drum temperature.
THERMOSTAT
TERMINALS
BIAS HEATER
TERMINALS
NOTE:
The control thermostats are not interchangeable
between an electric and a gas dryer. The resistance
of the bias heater is 28K ohms on the electric dryer
and 7K ohms on the gas dryer.
To diagnose the timer/accumulator, use the bar chart
located on the mini manual behind the switch trim.
Rotate the timer to a point in the particular cycle
you want to check. Find the appropriate location
the timer pointer is set in the cycles across the first
column. Read vertically down the chart from that
point. At each point you cross a shaded row, the
contacts listed at the left on the same row should
have continuity. Note the shaded areas are
proportional to the total time, so take several
continuity measurements at different points within
the cycle before determining the timer motor needs
replacement. As you can see from the example of a
gas dryer above, the contacts are made most of the
cycle.
Timer/Accumulator Bar Chart
Schematic Detail of Timer/Accumulator