GSI Outdoors PNEG-630 Air Pressure System, Airflow Operation, Troubleshooting Loss of Airflow

Troubleshooting Tips Portable Dryer Troubleshooting

Air Pressure System

•When inspecting the sensor make sure that the wheel going through the sensor is positioned in the center and is not touch- ing either side. If the sensor is scratched it is either bad or will probably go bad.

Airflow Operation

Symptoms: Dryer will indicate a "Loss of Airflow"

•After turning on a fan the computer must get a signal from the air pressure switch telling it that the fan is actually running and the plenum has been pressurized. If the switch does not show the air pressure within 20 seconds a "Loss of Airflow" shutdown occurs.

Troubleshooting: "Loss of Airflow"

•This error message indicates that the fan is running and the air pressure in the ple- num did not pressurize. First, verify that the fan is running, and the dryer is full of grain. There must be grain in the dryer or no pressure will develop. If the fan does come on and the dryer is full of grain, but a "Loss of Airflow" shutdown still occurs, check the air pressure switch circuit.

•Watching the blue light in the fan switch is the easiest way to tell if the air pres- sure switch is sensing air pressure. Each air pressure switch has a light in the fan switch that will only come on if air pres- sure has developed. Turn on the fan and after it has run up to about one half of its operating speed the light should go on. If the fan light is not coming on then the air pressure circuit is not sensing pressure.

•Try adjusting the air switch on the front of the plenum to see if it is just out of ad- justment. Use a straight blade screw-

driver and turn the adjusting screw coun- terclockwise. Turning it this way makes the switch more sensitive to pressure and will turn on the light easier.

•If adjusting the screw does not solve your problem consult the layout diagram of the input/output board. Look for the input for the problem switch. Example: Fan #1 switch's input is J1-13. This is a 12 volt DC input and it can be checked with a DC voltmeter. One of the following conditions will exist when checking this input.

NO AIR PRESSURE---ZERO VOLTS HAS AIR PRESSURE---12 VOLTS DC Remember when checking for 12 volts DC

you should always use one of the DC negatives for the black probe(-) of your voltmeter. Some of the terminals that may be used for the negative(-) are J5-11, J5-12 or J5-13.

•To check fan #1 for air pressure with a voltmeter:

1.Turn on the dryer.

2.Place the black probe(negative) of your voltmeter on J5-11 or J5-12.

3.Place the red probe(positive) of your voltmeter on J1-13. At this point there should be zero volts here be- cause the fan is not running.

4.Turn on the fan and watch your volt- meter.

•If the air switch is adjusted properly you should have zero volts across these test points when you first turn on the fan. Af- ter the fan has run up to about one half of its normal operating speed you should see the voltmeter change from zero volts to 12 volts DC. This also works in reverse when turning off the fan. After the fan is first turned off, the voltmeter should still show

12volts DC until the fan has slowed down to about one half of its operating speed. This is because even though the fan is

turned off it is still turning and developing some pressure in the plenum.

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