Direct-Spark Ignition Operation

DIRECT SPARK

NOTE:

Some models are equipped with a dual ignition system.

IGNITION

 

The dual ignition system contains two direct spark

OPERATION

 

ignition modules in parallel. Each module has its own

 

 

flame sense circuit and acts independently of the other.

 

 

If either bonnet limit thermostat opens because of high

 

 

heat or flame impingement, the entire ignition system

 

 

will shut down.

 

1. When a call for heat is received from the control supplying

 

24VAC to the ignition control module, the pre-purge delay

 

timer begins. This delay time allows any air/sediment to be

 

ejected prior to burner ignition. Following the pre-purge delay

 

period, the gas valve is energized and the spark ignitor sparks

 

for the trial for ignition period.

 

2. When a flame is detected during the trial for ignition period, the

 

spark ignitor shuts off and the gas valve remains energized.

 

3. If no flame is detected by the flame sense circuit, the ignition control

 

module will go into safety lockout. The valve will be turned off

 

immediately. If the module has multiple retries and no flame is detected,

 

the gas valve is de-energized and the module goes into an interpurge delay.

 

After this delay, the module will attempt another trial for ignition period.

 

This will continue until the number of retries has been used up. At that

 

time, the module will go into safety lockout.

 

4. Recovery from safety lockout requires one of the following:

 

a. A manual reset by opening and closing the loading door.

 

b. After one hour if the control thermostat is still calling for

 

 

heat, the module will automatically reset and the trial for

 

 

ignition period will start over. The push-to-start button

 

 

must be pushed to start the process going again.

 

5. Opening the loading door will cause the flame to extinguish.

 

Closing the door and starting the dryer will restart the trial for

 

ignition period.

 

6. Once the control thermostat has been satisfied and/or the

 

drying timer has been timed out, the ignition control

 

module(s) will be de-energized, the gas valve(s) will be de-

 

energized and the flames will extinguish.

 

7. The machine will continue to run in a cooldown mode without

 

heat. This process will cool the load to the touch and help to

 

eliminate wrinkling.

 

 

 

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