ADC ES50/50, Service Manual, Page: 12 / 32

12 American Dryer Corp. 450353- 1
G. MAIN DOOR SWITCH
The main door switch is located in the panel directly above the door. When the main door opens, the switch will also
open, preventing the dryer from operating. The main door switch is a safety device and should never be disabled.
H. SAIL SWITCH
The sail switch is located on the rear of the machine. A sail switch consists of a round damper plate on a lever arm
which is in contact with an electric switch. When the blower fan comes on, it draws air through the gas burner. This
creates a negative pressure inside the burner box, and this negative pressure pulls in the round damper and activates
the sail switch. If there is improper airflow, the damper will not pull in, preventing the burner from starting.
Improper airflow can be caused by improperly designed exhaust ducting where the duct run is too long or has too
many sharp bends in it. It can also be caused by faulty seals in the dryer or a lack of make-up air.
I. BURNER THERMOSTAT
A hi-limit thermostat is located at the top of the heat duct. This is an automatic reset disc-type thermostat set at 205°
F (96.11° C). If the flame in the burner should get too hot, this thermostat will shut off the burner. This is generally
caused by low airflow through the dryer.