CDD4 Duct Carbon Dioxide Transmitter
Installation Manual
May 27, 2013
2
Wiring
Deactivate the 24 Vac/dc power supply until all
connections are made to the device to prevent electrical
shock or equipment damage. Follow proper electrostatic
discharge (ESD) handling procedures when installing the
device or equipment damage may occur. Use 22 AWG
shielded wiring for all connections and do not locate the
device wires in the same conduit with wiring used to
supply inductive loads such as motors. Make all
connections in accordance with national and local codes.
This is a 3-wire sourcing device. Connect the plus dc or
the ac voltage hot side to the
POWER
terminal. The
supply common is connected to the
COMMON
terminal.
The device is reverse voltage protected and will not
operate if connected backwards. It has a half-wave power
supply so the supply common is the same as the signal
common. Several devices may be connected to one power
supply and the output signals all share the same common.
Use caution when grounding the secondary of a
transformer or when wiring multiple devices to ensure the
ground point is the same on all devices and the controller.
The analog output is available on the
CO2
terminal. This
signal is switch selectable for either voltage or 4-20 mA
active output. In voltage mode the output is selectable for
either 0-5 or 0-10 Vdc via the menu (the factory default is
0-5 Vdc). The current output operates in the active mode
and does not require a loop power supply. This means that
the signal current is generated by the transmitter and must
not be connected to a powered input or device damage will
result. Check the controller Analog Input to determine the
proper connection before applying power. Both current
and voltage signals are referenced to the
COMMON
terminal. The analog output signal is typically connected
directly to the Building Automation System (B.A.S.) and
used as a control parameter or for logging purposes.
An optional signal is the relay output available on the
N.O.
RELAY
terminals. The relay output is completely isolated
and has a Normally Open (NO) signal. This signal can be
used to directly control an alarm or ventilation fan.
The two-wire resistive temperature sensor output signal
can be ordered with various RTDs and thermistors to suit
all control applications and is available on the
TEMP
SENSOR
terminals.
Typical 4-20 mA wiring with 24 Vdc and all options
Typical 0-5 Vdc wiring with 24 Vac for CO2 only
DISC
ONTINUED
