American Dryer Corp. AD-400 - Manual (Page 40)

- one or more safety interlock switches are open. If any safety interlock switch is open the burner
ignition sequence will not be attempted.
Flame Failure - LED is lit if:
- Pilot is not established during 10-second trial-for-ignition
- Main flame is not established during TFI
- Main flame fails within 35 seconds of pilot TFI
- Flame fails during operation and is not re-established after one retry, (recycle mode)
Air Failure - LED is lit if:
- Air switch is not closed within 10 seconds of startup of blower
- Air switch is open during firing cycle.
System Unsafe - LED is lit if:
- A dryer safety device, connected in series with terminal 7, is opened. These safety devices
include the door switches, tilt switches, tumbler stop motion detector, high temperature limit
switches, airflow switches, and hi/lo gas pressure switch.
- A loose connection on the flame rod or spark plug.
- All purge time dip switches are in the off position
- Flame is detected out of sequence.
- Inductance is detected on sensor wires.
- Wiring fault on terminals 3,4, and 5.
- Internal controller failure.
- Air switch closed before startup.
Flame Signal - LED is lit when:
- The flame rod is heated by the pilot flame and applies a 3-11 VDC signal to the BCM. Insert
one probe of a DC volt meter into the flame signal port and put the other probe to ground. The
meter will read out the 3-11 VDC flame signal. If the flame signal LED flickers on and off, this
is a result of a weak flame signal which can be caused by an intermittent wiring connection
between the flame rod and BCM, a faulty ground connection, bad ground of the dryer, weak
pilot flame, or a dirty or defective flame rod.
Test/Reset Button
When this button is pushed in, the BCM will halt the ignition sequence, once pilot flame is
established. This allows the pilot flame to be adjusted.
b. Flame Rod/Spark Plug
The pilot flame is lit by the spark plug, while flame sensing is done through the flame rod. The
spark plug is energized when the pilot solenoid valve opens, igniting the pilot flame. The flame
rod sits in the pilot flame and sends a 3-11 DC volt signal to the burner controller module when it
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