Installation and Operating Instructions
CO
2
Room Sensor in the BAPI-Stat 3 Enclosure
with Common Ground Configuration
Specifications subject to change without notice.
26141_ins_room_CO2
6 of 6
rev. 04/27/18
The CO
2
outputs may be field configured for 0
to 5 VDC or 0 to 10 VDC outputs at any time.
Set the jumpers on J16 as shown in Figs 12
and 13.
The humidity outputs may be field configured
for 0 to 5, 1 to 5, 0 to 10 or 2 to 10 VDC outputs
at any time. Set the jumpers on J16 as shown
in Figs 14 and 15.
Note:
The jumpers on the pins not being
described are omitted for clarity on the figures
at right.
Output Selection
Diagnostics
Possible Problems:
Possible Solutions:
General troubleshooting Determine that the input is set up correctly in the controller's and building automation software.
Check wiring at the sensor and controller for proper connections. If there is corrosion, 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 terminals that the interconnecting wires are connected to at the sensor end and the
controller end. Disconnect the interconnecting wires from the controller and the sensor. With
the interconnecting wires separated at both ends measure the resistance from wire-to-wire with
a multimeter. The meter should read greater than 10 Meg-ohms, open or OL depending on the
meter you have. Short the interconnecting wires together at one end. Go to the other end and
measure the resistance from wire-to-wire with a multimeter. 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 for proper voltage (see specifications)
Incorrect CO
2
Wait 15 minutes after a power interruption.
Check all software parameters
Determine if the sensor is exposed to an external environment different from the room (conduit draft)
If the sensor is reading consistently high, make sure that the power supply to the unit can provide
240mA. A low power situation will cause high CO
2
readings.
Note: If the CO
2
sensor has consistently given high PPM readings for over 5 days, it will take up
to 14 days for the readings to return to normal.
Incorrect Humidity
Check all software parameters
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)
Incorrect Temperature Check the wires at the sensor and controller for proper connections.
Check the Temperature Output of the unit. Disconnect the temperature sensor’s wire (Terminals
TP+ & TP-) and measure the temperature sensor’s resistance across the sensor output pins with
an ohmmeter. Put the ohmmeter’s black lead on Terminal TP- and the red lead on Terminal TP+.
Compare the temperature sensor’s resistance to the appropriate temperature sensor table on the
BAPI website. (Go to www.bapihvac.com; click on “Resource Library” and “Sensor Specs”, then
click on the sensor type you have.) If the measured resistance differs 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 or
wall cavity draft)
Fig. 14:
CO
2
Output
0 to 5 VDC
Fig. 15:
CO
2
Output 0 to
10 VDC
Fig. 16: %
RH
Output 0 to 5
or 1 to 5 VDC
Fig. 17: %
RH
Output 0 to 10
or 2 to 10 VDC
