Garland MCO-GS-10M, MCO-GD-10M, MCO-GD-10E, MCO-GS-10E service manual Start Stage, End

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The safety lockout timer circuit starts timing the moment the trial for pilot ignition starts. When the timing period runs out, the trial for ignition ends, and the control module goes into lockout. Before another attempt to start can be made, the S86 must be reset. Reset by adjusting the thermostat or controller or to its "OFF" position. An alternate method is to shut the system power "OFF". If normal ignition does not occur, use the trouble shooting table to determine the problem.

START

STAGE 1

TRIAL FOR

IGNITION

1THERMOSTAT (CONTROLLER) CALLS FOR HEAT

2SPARK GENERATOR POWERED First valve (pilot) operator opens

3PILOT BURNER OPERATION

Pilot burner lights.

OR Pilot burner does not light.

Module senses flame

After 90 seconda system

current.

locks out; must be manually

 

reset.

aShutoff/lockout timing is stamped on module.

STAGE 2

MAIN BURNER

OPERATION

4FLAME CURRENT SENSED

∙Spark generator off.

∙Second valve operation (main) opens.

5MAIN BURNER OPERATION Module monitors pilot flame current.

POWER INTERRUPTION System shuts off, restarts when power is restored.

PILOT FLAME FAILURE

Main valve closed.

Module starts trial for ignition.

END

SERVICE

PRELIMINARY CHECK

6THERMOSTAT (CONTROLLER) SATISFIED Valves close, pilot and main burners are off.

The following visual checks should be made before trouble shooting and after installation or maintenance.

1.Check power to appliance and S86.

2.Manual shutoff cocks in gas line to appliance must be open.

3.Make certain all wiring connections are clean and tight.

4.First de-energize the system and wait at least one (1) minute. This resets the module allowing a return to start condition. Then energize the system.

5.Review the S86 system normal sequence of operation.

SYSTEM TROUBLE SHOOTING

Start the system by setting the thermostat or controller above required temperature. Observe system response. Establish type of malfunction or deviation from normal operation. Use the S86 Intermittent Pilot System Trouble Shooting Table to check for normal system operation.

Use table by following instruction questions in box. If the condition is true or okay (answer yes), go down to next box underneath. If the condition is not true or not okay (answer no), go right to the next box alongside. Continue checking

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Contents Garland Direct ON-SITE Service 1-800-451-1165 General InformationSpecification & Dimensions Table of ContentsOverview of Operational Sequences Common Wire Diagrams Component Access of Functional ComponentsDimensions & Specifications GAS Convection Oven GAS Specifications Main Pilot TotalPilot Orifice PRES. W/C AMT Orifice NAT PROCalibration of Thermostat Manual Controls MInstrumentation Weighting Calibration Notes Thermostat OperationElectronic Controls E Temp Electronic Control Failure CodesRobertshaw COM6000 Controller Operation of the Timer Function Operation of the Temperature Function Operation of the Pulse Function User Preference Offset for the Electronic ControllersTo SET Hold Temperature Timer Resolution ChangingTo SET Oven Into Pulse Mode Change the HertzChain Programming Safety Lockout TimeSecond Stage Main Burner Operation END Start StageTroubleshooting Ends S86 Checkout YES Spark Stops When Pilot is LIT?Start YES Spark Across IGNITOR/SENSOR GAPCheck Spark Ignition Circuit Check GroundingControl Module Flame Sensor Circuit Examples of Unsatisfactory Pilot FlamesAppearance Cause Top Front Center Component LocationsRight Front Lower FrontFile Name To Remove Doors from the OvenInstalling and Adjusting Door Chain To Reinstall Doors onto Convection OvenDisassembly of the Left Door Disassembly of the Right Door w/o window Page To Replace Convection Oven Motor Assembly Drawing Below To Replace or Adjust Door Latch MechanismConvection Oven Motor Assembly Page Common Wire Diagrams Page
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