13
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.
SERVICE
PRELIMINARY CHECK
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
2
2
2
2
SPARK GENERATOR POWERED
First valve (pilot) operator opens
3
3
3
3
PILOT BURNER OPERATION
Pilot burner lights.
Module senses flame
current.
OR
Pilot burner does not light.
After 90 second
a
system
locks out; must be manually
reset.
a
Shutoff/lockout timing is stamped on module.
4
4
4
4
FLAME CURRENT SENSED
•
Spark generator off.
•
Second valve operation (main) opens.
5
5
5
5
MAIN BURNER OPERATION
Module monitors pilot flame current.
6
6
6
6
THERMOSTAT (CONTROLLER) SATISFIED
Valves close, pilot and main burners are off.
1
1
1
1
THERMOSTAT (CONTROLLER) CALLS
FOR HEAT
POWER INTERRUPTION
System shuts off, restarts
when power is restored.
PILOT FLAME FAILURE
Main valve closed.
Module starts trial for ignition.
START
STAGE 1
TRIAL FOR
IGNITION
STAGE 2
MAIN BURNER
OPERATION
END
Summary of Contents for MCO-GD-10M
Page 25: ...25 SECTION 4 COMMON WIRE DIAGRAMS...
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