Installation and Operating Instructions
Duct and Outside Air Humidity (H200-H300)
4 to 20mA or 0 to 5V Humidity Output with Optional Temperature Sensor
Building Automation Products, Inc., 750 North Royal Avenue, Gays Mills, WI 54631 USA
Tel:+1-608-735-4800 • Fax+1-608-735-4804 • E-mail:[email protected] • Web:www.bapihvac.com
9938_ins_hum_temp_duct_out_5_20
4 of 4
rev. 02/15/18
Specifications subject to change without notice.
Temperature Diagnostics
Humidity Diagnostics
Possible Solutions:
- Confirm the input is set up correctly in the controller’s software
- Verify that the sensor wires are not physically shorted or open
- Check wiring for proper termination
- Measure the temperature at the temperature sensor’s location using an
accurate temperature standard. Disconnect the temperature sensor wires and
measure the temperature sensor’s resistance with an ohmmeter. Compare the
temperature sensor’s resistance to the appropriate temperature sensor table on
the BAPI website. If the measured resistance is different from the temperature
table by more than 5%, call BAPI technical support. BAPI’s web site is found at
www.bapihvac.com; click on “Resource Library” and “Sensor Specs” then click on
the type of sensor you have.
Possible Problems:
Unit will not operate
Humidity output is at its maximum
value of 5V or 20mA
Humidity output is at its minimum
value of 0V or 4mA
Humidity reading in controller’s
software appears to be off by
more than the specified accuracy
Output
Humidity Formula
4 to 20mA
%RH =(mA-4)/0.16
0 to 5VDC
%RH = V/0.05
Possible Solutions:
- Check for proper supply power. (See page 2 for wiring diagram and power
specifications)
- Make sure the humidity sensor is wired properly.
- Make sure the humidity sensor is wired properly.
- Check all software parameters
- Determine if the sensor is exposed to an external air source different from the
intended measured environment or reference device.
- Check the Humidity transmitter output against a calibrated reference such as a
2% accurate hygrometer. Measure the humidity at the sensor’s location using the
reference meter, then calculate the humidity transmitter output using the humidity
formula at left. Compare the calculated output to the actual humidity transmitter
output (see the wiring diagram on page 2 for the humidity transmitter output wire
colors). If the calculated output differs from the humidity transmitter output by more
than 5%, contact BAPI technical support.
Possible Problems:
Controller reports Incorrect
temperature
Filter Care
A sintered filter protects the humidity sensor from various airborne particles and may need periodic cleaning. To do this,
gently unscrew the filter from the probe. Rinse the filter in warm soapy water and rinse until clean. A nylon brush may be
used if necessary. Gently replace the filter by screwing it back into the probe. The filter should screw all the way into the
probe. Hand tighten only. If a replacement filter is needed, call BAPI.
BA/HDOFS3
Stainless Steel Sintered Filter Replacement for Outside Air Units
