Carrier VVT Zone Installation And Startup Manual page 22

Installation
Wiring diagram for #33ZCSPTCO2:
#33ZCT55CO2
Wire the sensor to the controller. See appropriate diagram below.
1
Install a field supplied 250 Ohm 1/4 watt 2% tolerance resistor across the controller's RH/CO2 and Gnd
2
terminals.
Verify that the RH/CO2 jumper is set to 0-5Vdc on the VVT Zone Controller.
3
18 VVT Zone Controller