American Dryer Corp ML-310 Phase 7 service manual Valves are not Field Repairable

e. The Manual Reset Basket (tumbler) Hi-Limit Switch is a thermostat type switch located above the lint basket. Its function is to discontinue heat (flame) in the event of an over temperature situation (above 225º F [107º C]).

225º F (107º C) Thermostat

f. The gas valve used in the dryer is of the redundant type which means that the gas valve is actually two (2) gas valves in one (1); one (1) in series with the other. This is a safety feature, which provides protection against gas flow in the event that one

(1) of the valves does not seat properly. The valve also regulates the incoming gas pressure.

NOTE: THE DIRECT SPARK IGNITION (DSI) GAS	Redundant Gas Valve
VALVES ARE NOT FIELD REPAIRABLE.

g.Normal Operation of the DSI System (refer to the illustration on page 17).

1)The DSI System consists of a microprocessor-based control module, along with an Ignitor/Flame- Probe Assembly. This control utilizes a high voltage synchronous spark ignitor and a rectified flame sensor probe signal to locally control ALL basic functions in the gas burner.

On a call for heat by the dryer’s controls, 24 VAC is applied to the DSI module at which time the module’s light emitting diode (L.E.D.) indicator will light “red” indicating that power has been established to the module. Almost immediately (up to approximately 1.5-seconds [prepurge]) the indicator will light “green,” the gas valve opens and the spark burst will be evident (on) for approximately 8- seconds. The burner flame should now be established/confirmed.

If at this time the flame has not been established and confirmed, the DSI module will “LOCKOUT” and the module’s L.E.D. indicator will light “red” and stay on continuously. “Burner Ignition Control Fault” will display. To clear this fault code press the “CLEAR/STOP” key.

Once the burner flame is established and confirmed, the DSI module indicator will light “green,” and the burner system will continue through a normal heating cycle, where the DSI system will cycle on and off as required by the dryer’s controls.

During the normal heating cycle, should a “FLAMEOUT” occur (i.e., severe air turbulence forces the flame away from the Ignitor/Flame-Probe Assembly), the DSI module will shut the gas valve off and immediately try to reestablish the burner flame. The DSI module will attempt to light the burner ONLY ONCE. If flame is not established, the DSI module will “LOCKOUT” and “Burner Ignition Control Fault” will display. To clear this fault code press the “CLEAR/STOP” key.

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