TROUBLESHOOTING
Continued
7.Replace removed plug in hole. Perform a trial operation.
8.If repeated resetting of the thermal limit switch is required, have the product serviced by an authorized service center.
OBSERVED FAULT
Tubular heating element heats up but no rush of warm air is felt at outlet vents
Rotate fan by hand to determine if fan
rotates easily
OBSERVED FAULT
Motor starts and runs but cool air is felt
Does tubular heating element heat up?
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| WARNING: |
| WARNING: | |||||||
| Hot Surface! |
| Hot Surface! | |||||||
1 Look for defective | 3 | Check for blocked | ||||||||
| tubular heating |
| air intake openings | |||||||
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| element |
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2Open tubular heating element
Fan is difficult
to rotate
1Fan or motor obstructed
2 Dry motor bearing
Test Procedure
Fan rotates easily
by hand
3 Open motor coil
Test Procedure
1. Look for Defective Tubular Heating |
Element |
After approximately 2 minutes the tubular heat- |
ing element should glow a dull red when placed |
in a dark area. |
2. Open Tubular Heating Element |
Disconnect element wires (black and white). |
1.Fan or Motor Obstructed
Remove obstruction. Clean heater.
2.Dry Motor Bearing
If the fan is difficult to turn, then motor bearings are defective. Bearings are permanently lubricated, therefore motor should be replaced.
3. Open Motor Coil
Disconnect motor wires (black and white). Attach the ohmmeter leads to the motor wire terminals. Using the 0 to 200 ohm scale, measure the resis- tance of the motor coil. If the resistance is not approximately 6.0 to 6.4 ohms at 73° F, the motor is defective and should be replaced.
Note: Resistances may vary due to motor temperature.
Figure 6 - Testing Motor
Attach the ohmmeter leads to the element wire |
terminals. Using the 0 to 200 ohm scale, measure |
the resistance of the element. If the resistance is |
not 8.5 to 11 ohms at 73° F the element is defective |
and should be replaced. Note: Resistances may |
vary due to element temperature. |
3. Check for Blocked Air Intake Openings |
Check for blockages around vent openings at bot- |
tom of heater (see Figure 5, page 6). |
Figure 7 - Testing Heating Element
www.desatech.com | 7 |