Airstream PNEG-343 service manual Burner Safety, Burner Test Fire

DRYER PRE START CHECKS

crease the speed. Make sure the drive chain tension is properly ad- justed and all sections of the meter- ing rolls rotate. Turn the unload switch off after these checks are complete. The bottom auger will continue to run for 30 seconds after the switch is turned off to allow for cleanout.

FAN SWITCHES

Bump each fan switch and observe the fan rotation. The fan should run counterclockwise. Sometimes on three phase models all motors will run backwards. They can easily be reversed by interchanging two of the three power supply wires. Reverse the two outside wires, L1 and L3, and leave the middle one in the same position.

purge delay of approximately 10 seconds. Gas pressure should be shown on the gauge. At this time adjust the burner hi-lo fire thermo- stat to 200°F, causing the burner to operate on hi-fire. This thermostat is located on the front left side of the dryer. Observe the gas pressure on gauge, and turn the thermostat to its minimum setting, causing the burner to cycle into lo-fire. As the burner thermostat is turned down the gas pressure should also show a notice- able drop, indicating that the hi-fire solenoid is closed and the burner is being supplied with less gas through the low fire control valve. At this time set the hi-fire and lo-

fire pressure settings. Use the pressure regulator for hi-fire and the ball valve for lo-fire. The ther- mostat should cycle between high and low, approximately 4 to 5 times per minute.

Approximate settings should be:

LP Gas	Hi-Fire 6-15 lbs.
	Lo-Fire 2-6 lbs.
Natural Gas	Hi-Fire 6-10 lbs.
	Lo-Fire 1-3 lbs.

If the burner remains on hi-fire and does not cycle, increase the regulator setting on the propane models, or the supply valve on the natural gas models in order to reach the thermostat setting. If the burner remains in lo-fire and does not cycle,

Note: If the dryer is empty, the fans or burners will not operate. The fans cannot create enough static pressure to engage the air switch. You will receive a loss of airflow message.

BURNER SAFETY

To check the burner safety function, first makesurethemaingasvalveisoff.Turn the fan switch on and allow the fan to start. Then, turn the heater switch on for that fan. The dryer will shut down after 20 seconds. The safety message, "Burner 1 warning flame not detected" will appear. Restart dryer and repeat for each fan/heater.

BURNER TEST FIRE

Test fire each burner by starting the fan. Then, turn the burner switch to on. Turn on the fuel supply, and the burner should ignite after a short

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The dryer fan and heater controls featuring: 1-pressure regulator, 2-lo-fire control valve, 3-high pressure solenoid, 4-low pressure solenoid, 5-hi-lo fire thermostat, 6-fuel supply line, 7-LP solenoid or supply ball valve(NG), 8-air pressure switch and 9-liquid filled gauge.

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