Maytag MLE/MLG23MNA Gas Conversions, Safety Features, Power Interruptions, Ignition Failures

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General Information

Holding

Coil

 

 

Radiant

 

 

Sensor

To

Booster

Motor

 

Coil

Igniter

 

 

 

Valve 1

Valve 2

Because of the relatively low resistance of the hot igniter, most of the line voltage is dropped across the secondary coil. The remaining voltage is dropped across the booster coil and igniter.

The secondary coil now opens the second valve releasing gas across the still extremely hot igniter. The gas ignites immediately and the burner flame is established.

Note: Since the igniter will cool, the tip is positioned in

the burner flame which keeps it hot and resistance low.

The ignition cycle is now completed and the drying cycle begins.

Gas Conversions

The gas valve is set for use with natural gas when shipped from the factory. Because of differences in operating pressure and heat content of gases, the valve must be converted to use fuels other that natural gas.

Conversion kits are available to convert from natural to L.P. and back to natural. Check parts catalog for correct part number.

Safety Features

The design of the system provides for fail-safe operation in the event of power interruption, ignition failure, or flame failure as described below.

Power Interruptions

If the power to the burner assembly is cut off, either by opening the dryer door or by a power line failure, both valves in the gas valve assembly will close. Gas flow will cease.

When power is restored to the valve, the radiant sensor will start the process again. However, if the radiant sensor has not cooled and the contacts are still open, the secondary coil will receive full voltage and OPEN with no gas flowing through the secondary valve.

Since the secondary coil is in series with the booster coil, the reduced current flow through the booster coil is insufficient to create a strong enough magnetic field to help open the first coil valve. When the radiant sensor cools and closes its contacts, the sensor will shut the secondary coil again, providing a full current flow to the igniter and the booster coil, and system will go through a normal ignition sequence.

Ignition Failures

When the radiant sensor reacts to the heat from the igniter and the contacts open, the secondary coil energizes, opening the secondary valve. This allows gas to flow to the burner.

If no gas is present or the gas flow is not ignited, the radiant sensor will cool and the contacts will close, causing the secondary valve to close, thus allowing the igniter to reheat. The system will continue to cycle in this manner until normal ignition occurs or the dryer is turned OFF.

Flame Failure

If the burner flame should go out for any reason, the radiant sensor contacts will close in about 45 seconds and the gas system will go through a normal ignition sequence.

©2004 Maytag Appliances Company

1602904 Rev. 0

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Contents Commercial Single Stack Dryers Important Information Table of Contents Important Safety Information Proper Grounding and Polarization of 120 Volts Wall Outlets About Ground WiresGeneral Information Related Publications Explanation Grounding InstructionsCommercial Dryer Nomenclature ServiceParts and Accessories Model IdentificationAir movement measured in cubic feet per minute TERMINOLOGY/DEFINITIONS Term DefinitionsWater 1 o F HOW IT Works GAS Valve AssemblyRadiant Sensor Contact Closed Function of Gas Valve SystemIgnition Failures Safety FeaturesPower Interruptions Gas ConversionsGeneral Information Exhaust Ducts General SpecificationsWattage Specifications Drive Motor Check Electrical TroubleshootingDrive Motor Test Centrifugal SwitchAir Shutter Adjustment Motor Test CordManometers How to UseNoisy and/Or Vibration Mechanical Troubleshooting Will Not RunWill Not Shut-Off Will Not DrySingle Dryer Troubleshooting Guide Operator Dryer Stopped with Zero Minutes Remaining DisplayCannot Enter Or ExitDropped Into Machine Credited Are Eventually Lost Display Flashes User ModeKey Inputs Control Does NotRespond To Dryer Drum Will Not Turn To Coin 1 or ResponsePoint Is Used Will Not Keep Time Of Day During Power InterruptionsWill not Respond to handheld No DecimalDryer Will Not HeatDryer Diagnostic Program Single Dryer Diagnostic ProgramDoor Sense Problem Single Dryer Diagnostic CodeVAC Lower Dryer Has Zero Minutes Remaining Display Stack Dryer Troubleshooting GuideDisplay Is Blank Abnormal Display Or Function Upper orKeypads ControlBoard Does NotInterruption Response To Coin Or CoinKeep Time Day DuringCannot Dryer Runs Without Program Selection Drum Will Not Turn Stack Dryer Diagnostic Program D1 or d17 Door Sense Problem Stack Dryer Diagnostic CodeVoltage Problem Transformer Touch Pad AssemblyControl Panel Microprocessor BoardCoin Sensor Service Door SwitchCoin Vault Switch Door AssemblyFront Panel Reversing Door AssemblyDoor Disassembly Top Cover Door SwitchOutlet Duct, Shroud & Tumbler Front Front Shroud Assembly RemovalBelt Lint FilterBearing & Pads Front SealBaffles Rear Shroud AssemblyInstalling Drive Belt Back Seal Roller and Bearing AssemblyLow-cycling Thermostat Blower AssemblyThermostats Cycling ThermostatBlower Idler Arm Assembly Exhaust Duct Pipe Assembly BreakdownMotor Switch Drive Motor Assembly Igniter Gas Valve AssemblyCoils Heater Enclosure Gas ValveCombustion Cone Inlet DuctStack Dryer Sloped Front Models Service Panel and SwitchAccess Cover Coin Drop MicroprocessorSwing Out Away Remove ScrewsStack DRYER-MN Models Stack Dryer Sloped Front PRMachine-In-Use Light Push-To-Start SwitchTimer Selector SwitchStack DRYER-FLAT Front Models Front Shroud AssemblyMotor & Heater Relays Appendix a Pricing Programming ProceduresFixed Vend Pricing SET UP Codes Money Counter Option Steps 3. thru 9. codes are skipped if mode 2.00 is selected00 7.STARTING of Special Pricing Hour Value of Coin 2 Canadian Dollar Drop White & Colors keypad Example Stacked Models Only Dryer Diagnostic ModeDryer Help Mode All Single Load Models