Installation and Operating Instructions
Delta Style Room Humidity Transmitter with Optional Temp. Sensor
BA/#-Hxxx-R
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
Specifications subject to change without notice.
27417_ins_Delta_RH
4 of 4
rev. 04/15/14
1 Mount and wire the transmitter per the instructions above (Mounting and Termination)
2 Read the optional passive sensor value at the controller. It should show the room temperature per the accuracy spec above.
3 Test and Balance option is described in the “Configuration Adjustments” above and will only affect the optional passive tem-
perature sensor [TEMP +] and [TEMP -] output. As you switch from High to Low and to Norm you should see the resistance
change per the table in section “Optional Test & Balance Switch”.
4 If the controller is not hooked up or power has not been applied yet, disconnect the [TEMP +] wire and measure the [TEMP
+] terminal and [TEMP –] terminal with an Ohm meter for a thermistor or an RTD. A solid state sensor must be read from a
controller. The resistance should correlate with the temperature in the room. Resistances to temperature charts are available
on line at BAPI web site “BAPIHVAC.com”. Reconnect the [TEMP +] wire when finished.
5 Power up the transmitter and read the output values after 2 seconds, per the instructions below.
•
Voltage Output:
Read the voltage output with a volt meter from [GND] to [V OUT]. Read the RH voltage in proportion to
the RH sensor. See the Humidity Formula chart below.
• Current Output;
Read the current output with a current meter in series with the [GND] terminal and field wire. Read the
RH current (between 4-20mA) in proportion to the RH sensor. See the Humidity Formula chart below.
6 If this is a display transmitter then follow the “Configuration Adjustments” to set the °F or
°C indication and unit interval toggle rate.
• °F or °C Indication:
Set the display units to ˚F or ˚C as needed with J2 jumper
• Unit Interval Toggle Rate:
Set the temp. and humidity display rotation with R6.
Problems:
General Troubleshooting
Incorrect Humidity
Incorrect Temperature
Faulty %RH/Temperature
Sensor Chip
Commissioning
Diagnostics
Possible Solutions:
• Determine that the input is set up correctly in the controller and building automation software.
• Check wiring at the sensor and controller for proper connections.
• Check for corrosion at either the controller or the sensor. Clean off the corrosion, re-strip the
interconnecting wire and reapply the connection. In extreme cases, replace the controller,
interconnecting wire and/or sensor.
• Label the interconnecting sensor wires then disconnect them at the sensor end and controller end.
With the wires disconnected at both ends, measure the resistance from wire-to-wire with a multi-
meter. The meter should read greater than 10 Meg-ohms, open or OL depending on the meter.
Now short the interconnecting wires at one end. Go to the other end and measure the resistance
from wire-to-wire with a multi-meter. The meter should read less than 10 ohms (22 gauge or larger,
250 feet or less). If either test fails, replace the wire.
• Check power supply/controller voltage supply.
• Disconnect sensor and check power wires for proper voltage (see specifications).
• Check all controller software parameters (V/I/Ω).
• If available, check the sensor against a calibrated instrument such as a hygrometer.
• Determine if the sensor is exposed to an external environment different from the room (conduit
draft, diffuser above, radiation below, etc.).
• Adjust the offset POT R20 to your reference value (±5%). (See “Humidity Reading Offset” section)
• Determine that the sensor’s wires are properly connected to the correct controller input terminals.
• Check the wires at the sensor and controller for proper connections.
• Measure the physical temperature at the temperature sensor’s location using an accurate
temperature standard. Output to Controller; Disconnect the temperature sensor’s wire terminals
[TEMP+] & [TEMP-] and measure the temperature sensor’s resistance across the sensor
output pins with an ohmmeter. Compare the temperature sensor’s resistance to the appropriate
temperature sensor table on the BAPI web site (BAPIHVAC.com). If the measured resistance is
different from the temperature table by more than 5% call BAPI technical support.
• Determine if the sensor is exposed to an external environment different from the room (conduit
draft, diffuser above, radiation below)
• On power up, a normally-operating unit will display 0%RH and 0.0 ˚F or °C for 2 seconds. After
2 seconds, the unit will begin to display the actual %RH and temperature. If there is no display
reading after 500 seconds (0%RH and 0.0°F or °C), then the unit will default to a %RH reading of
100% and a temp reading of 0.0°, indicating a bad sensor. Replace the unit.
Output
Humidity Formula
4 to 20mA
%RH =(mA-4)/0.16
0 to 5VDC
%RH = V/0.05
0 to 10VDC
%RH = V/0.1
2 to 10VDC
%RH = (V-2)/0.08
