American Dryer Corp. Hot Surface Ignition System ADG-530 User Manual
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36E Redundant Gas Valve
WARNING: THE HSI GAS VALVES ARE NOT FIELD REPAIRABLE.
IMPORTANT: THERE ARE NO PARTS AVAILABLE FOR FIELD REPAIR. Replace
gas valve only with exact model and/or type number as noted on gas
valve.
d . The HSI 24 VAC GAS VALVE(s) used are of the redundant type which means the
gas valve is actually two gas valves in one; one in series with the other. This is a
safety feature which provides protection against gas flow in the event of a failure of
one of the valves to seat properly. Other features are that the gas valves have a
manual shut off, a pressure tap outlet, and are designed for easy conversion to
regulated L.P. gas.
Upshot Burner Tube
with Hot Surface Ignitor (HSI)/Flame Sensor Assembly
c. The HOT SURFACE IGNITOR/FLAME SENSOR ASSEMBLY is located in the
burner flame area and is used to ignite the gas by the use of a HOT SURFACE
IGNITOR. To provide feedback information to the HSI module a FLAME SENSOR
is used to determine whether the burner flame is evident (on).
The HOT SURFACE IGNITOR is a silicon carbide ignitor that upon application of
24 VAC will glow bright orange for the inter-purge time period. The proper
location of the silicon carbide ignitor is very important to achieve optimum system
performance for both ignition and flame sensing.
After the inter-purge period the gas valve will open.
Upon ignition, the resistance in the flame sensor electrode changes and the in-
formation is sent to the HSI module via the sensor probe lead connection to the
module. Once the resistance is changed and sensed, the HSI module will sustain
the gas flow (provide 24 VAC power to the gas valve).