American Dryer Corp MLG-460 manual

Page 49

Once the flame probe signal is detected by the burner controller module (BCM), it waits 5-seconds to allow the pilot to stabilize and then opens the main motorized gas valves (BCM terminal #5) in sequence.

The lower valve opens first. Upon full opening, its’ internal switch closes, enabling the second motorized valve to open and full flame to be achieved.

If flame failure occurs within a 35-second period, the BCM (burner controller module) will recycle the ignition sequence once. If flame fails a second time, the system will lock out and the “FLAME FAILURE” pilot will light.

Once main flame is established, the burner will remain in the full fire mode until the drying set point temperature has been reached. At this point, the dryer computer will cycle the top motorized gas valve to the closed the position. The “OFF” mode will be maintained until the dryer’s temperature falls below the drying set point temperature. The motorized valve will then be returned to the full fire position. With voltage applied to the motorized valve, it moves to the full fire position. “OFF” is achieved when no voltage is applied to the motorized valve.

7)Gas Burner Start-Up

a)New gas lines are filled with air and must be purged before the burner will light. To do this close the upper manual shut-off valve, but leave the pilot line shut-off open. Push in the Test and Reset Button on the cover of the burner controller module (BCM). This will “freeze” the ignition sequence when the pilot flame ignites. This allows time to examine the pilot flame, and measure the flame rod signal to the BCM.

b)Connect a pressure gauge or water tube to the pilot gas pressure tap. Start the dryer;

Follow the ignition process by referring to the “Sequence of Operation” section of this manual.

c)When the pilot flame is ignited, the pilot gas pressure should measure 3.5-inches water column (W.C.) - 8.70 mbar - for natural gas and 1.5-inches water column (W.C.) - 3.73 mbar - for L.P. (liquid propane) gas. The pilot flame should be about as big as a tennis ball.

d)Once the pilot has been properly set, remove the pressure gauge from the pilot line connect a differential pressure gauge between the main gas pressure tap (HI port) and the air pressure tap (LO port) on the side of the gas burner box. The lines connecting the gauge to these taps must be long enough to allow the gauge to sit outside of the dryer so that the burner section access door can be closed when the dryer runs. Running the dryer with these doors open will give an incorrect air pressure reading.

e)Once this differential gauge is installed, open the main gas shut-off valve and push the Test and Reset Button on the burner controller module (BCM) so that the button springs out. Restart the dryer. The ignition process should now continue to the full gas flow state. The differential gauge should read 2.5 inches water column (W.C.) - 6.22 mbar - for natural gas and 1.25 inches water column (W.C.) - 3.1 mbar - for L.P. (liquid propane) gas. If it does not, adjust the top motorized valve as described in the Top Motorized Gas Valve on page 43.

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Contents MLG-460 Retain This Manual In a Safe Place For Future Reference For Your Safety Page Table of Contents Returning Warranty Cards Parts Returning Warranty Parts Service PartsTroubleshooting TOC Section What to do if YOU Smell GAS Safety PrecautionsPage Specifications SpecificationsSpecifications Reassembly of Dryer Installation ProceduresPage Page Location Requirements Internal AIR, Electric and Water Connections Page Page Page Page Page Left Drum Motor External Supply Connections Page Page Electrical Requirements Electrical RequirementsMLG-460 Page Fresh AIR Supply Requirements Preparation for Operation PRE START-UPCleaning Routine MaintenanceMonthly Component System Descriptions Page Page Main AIR Blower and Heat Reclaimer System Page Compressed AIR System Page Page GAS Burner and Ignition System Switch #2 Intermittent Pilot Page Page Page Page Page Page Page Safety Devices Door Open Parts ServiceWarranty Returning Warranty CardsReturning Warranty Parts Page Troubleshooting Possible Solutions Power MalfunctionsProbable Causes No Control Power Blue Light Off Machine Main Power Shuts Down Blue Indicator Off 2CRB Sprinkler Circuit Description Page Front Panel Blue Light and RED Light on Possible Solutions Unless the Water Valve to the Sprinkler is Closed General DescriptionBurner Ignition Burner Controller Input Signal ComponentsIntroduction Burner Section Input Circuit Component DescriptionLoad Door Switch DS1B Stop Detector Relay Contact SMD no Output Signal Component DescriptionGAS Fault Message gas system only Heater Fault Message Possible Solutions Page Page AIR Fault Message HI-TEMP Fault Message Possible Solutions Drum Fault Message Page Tumbler Basket Section Electrical Components Tumbler Basket Section Electrical MalfunctionsFollowing is for 2-Door Models only Rear Panel Control Problems Probable Causes Possible Solutions PLC OUT PIN 7 = Unload Door Open PLC OUT PIN 10 = Front UP Unload 1 Selection Probable CausesDoor Open Problem Drum Fault Message Malfunction Probable Causes Page Rear Down Switch LS2 Front Door SwitchLint Drawer Proximity Switches Base Section Electrical MalfunctionsTumbler Basket Tilt Problems Level Fault Lint Chamber Pressure Switch PS3Probable Solutions Page Lint Screen Mechanism Problem Screen Fault Lint Chamber Air Pressure Problem AIR Fault Pendant Electrical Components Pendant Control MalfunctionsVerify Pendant Electrical Signals ML-460 Pendant Assembly Diagram Temperature Sensing Page Temperature Measurement and Sensing Problems Motors Circuit Wiring to the Analog Input ModuleMotor Protection Device Descriptions Motor Actuation Problems Probable CausesMotor Fault Screen FaultGAS Fault AIR Fault