5–5
5.9 CHECKING THE HUMIDISTAT
1. Start by adjusting the humidistat to the high end of the scale (close to 100% relative
humidity). At this point, the humidistat should not be calling for drying. The contacts
inside the humidistat should be open, and you should be able to measure 24 VAC
across the contacts.
2. Next, adjust the humidistat to the low end of the scale (close to 10% or 20% relative
humidity). Now the humidistat should be calling for drying, and the contacts inside
the humidistat should be closed. You should see 0 Volts across the contacts.
3. You can also check the wiring between the humidistat and the HC-150. The humi-
distat is connected to terminals on the printed circuit board. When the humidistat is
not calling for dehumidification, you should see 24 VAC across the contacts.
5.10 CHECKING THE DRIVE MOTOR, WHEEL AND SEALS
1. Before you can remove the wheel, you must remove the drive motor. Figure 1–4
shows the drive wheel and belt.
2. Pull back the tensioner to loosen the drive belt. Remove the belt from the drive
sprocket on the motor.
3. Unplug the wiring connectors to the motor. Be careful not to pull too hard on a
connector. This could damage the wiring or the circuit board.
4. Remove the motor and drive assembly. These are mounted on the right-hand roller
wheel assembly.
5. Remove the small roller wheels which are located on each side of the
HoneyCombe
®
wheel. To remove a roller wheel, lift the wheel shaft up. Pull the
bottom of the shaft toward you, then down.
6. Gently lift the wheel a bit and pull it forward. Be careful not to damage the lower seals.
7. The small passages in the HoneyCombe
®
wheel may be plugged by dust or dirt. To
inspect the passages, hold the wheel upright. Hold a lamp with a 60 watt bulb
behind the wheel. If the passages are clear, the light from the lamp should shine
through the wheel. Because the passages are so small, you won’t be able to see
the light directly. Instead, you should see the glow from the light. If any part of the
wheel is plugged, you will see a dark area.
8. If the wheel seems to be plugged, it may be possible to clean it. Use a wet/dry
vacuum, and a dusting brush attachment with a soft bristle brush. Vacuum both
surfaces of the wheel.
9. If you cannot clear the wheel using the vacuum, you may use compressed air to
help the process. You must do this carefully, so that you do not damage the wheel.
The compressed air should be dry and free of oil. Don’t use a pressure higher than
30 PSIG. Use the compressed air on one side of the wheel, and the vacuum on the
other. Don’t hold the compressed air hose closer than 12" to the face of the wheel.
10. This type of wheel is washable. It is best to clean the wheel using clean water only.
If you must use a detergent, choose a mild type (enzyme or dish-washing deter-