Install Instructions

To wire a Duct Probe model, complete the following steps:
1. Route the wires from the controller to the unit
through the conduit hole in the housing.
Important: If you use a conduit fitting (not
provided), a washer is provided to support
the fitting in the housing. If you do not use
the washer, the fitting could stress the plastic
housing.
2. Break out the conduit knockout from the cover with
pliers to accommodate the wiring. See Figure 2.
3. Connect the wires to the appropriate terminals of the
wiring block. See Figure 3.
4. Press the cover onto the base.
Figure 3: Wiring the Duct Probe Humidity Element
Table 3: Wiring the Duct Probe Humidity Element
Number Description
1 TEMP
2 TEMP
3 VOUT
4 COM
5 PWR
Troubleshooting
If the Duct Probe Humidity element does not function
correctly:
1. Verify that the unit is mounted in a location that is
away from drafts, moisture, and sunlight.
2. Use a humidity tester with accuracy greater than the
accuracy of the element, such as an optical dew point
hygrometer, to determine the percent of relative
humidity (RH). Make sure that the accuracy of the
tester is ±2% between 20% and 80% for 2% models,
and ±3% between 20% and 80% for 3% models.
Note: The humidity tester and the element
must sense the air at the same temperature.
Before testing, wait 30 to 60 minutes for the
tester to stabilize to ambient temperature
and humidity. A temperature difference of as
little as 1°F (0.6°C) can cause a difference in
measured RH of over 2.5% RH.
3. Calculate the percent of RH indicated by the element
as follows:
a. For 0 VDC to 10 VDC output, multiply the output
voltage by 10. For example: 7.5 VDC x 10 = 75% RH
b. For 0 VDC to 5 VDC output, multiply the output
voltage by 20. For example: 3.5 VDC x 20 = 70% RH
Note: ±0.9°F (±0.5°C) corresponds to an error of
about ±2% RH at 25°C if RH is at a high level, for
example: 70%.
4. Compare the RH readings between the humidity
tester and the element. If the difference is more
than the sum of the acceptable errors, replace the
humidity element.
5. If the humidity output is lower than expected, check
the position of the output jumper setting.
HE-69xx0NP Duct Probe Humidity Element with Temperature Sensor Installation Guide 3