GREYSTONE CDD5 Series Carbon Dioxide-Humidity Temperature Transmitter Instruction Manual
- June 12, 2024
- Greystone
Table of Contents
Carbon Dioxide/Humidity/ Temperature Transmitter
CDD5 Series – Installation Instructions
INTRODUCTION
The room CO2/RH/T Transmitter incorporates three sensors and the room CO2/T Transmitter incorporates two sensors in one attractive wall mount enclosure for the most efficient environmental monitoring and control system. It uses dual channel optics and LTA (long term adjustment) signal processing technology to monitor CO2 levels within a range of 0 to 10,000 ppm, a field- proven RH sensor to monitor relative humidity from 0-100 %RH (If included in model ordered) and a thermistor to measure temperature over common field- selectable ranges. All measurements are continuously available on separate outputs as linear 4-20 mA or 0-5/0-10 Vdc signals. The device includes an LCD for configuration and operating parameters are programmed using a keypad for specific applications. Options include a control relay, override switch and slide pot set-point control.
BEFORE INSTALLATION
Read these instructions carefully before installing and commissioning the
device. Failure to follow these instructions may result in product damage. Do
not use in an explosive or hazardous environment, with combustible or
flammable gases, as a safety or emergency stop device or in any other
application where failure of the product could result in personal injury. Take
electrostatic discharge precautions during installation. Do not exceed
device ratings.
NOTE: This CO2 sensor incorporates a Self Calibration feature to correct CO2
sensor drift. This feature is recommended for applications where the sensor
will be exposed to fresh air (400 ppm CO2) at least one hour per day. If the
monitored space is occupied 24 hours or consistently maintains higher or lower
levels of CO2 , it is recommended that this feature be turned off, but yearly
calibration will be required. If the self calibration is disabled at
installation time without allowing for 7 day auto calibration cycle, then a
manual calibration should be performed to ensure accuracy of the device.
MOUNTING
The
transmitter installs directly on a standard electrical box and should be
mounted five feet from the floor of the area to be controlled. Do not mount
the sensor near doors, opening windows, supply air diffusers or other known
disturbances. Avoid areas where the detector is exposed to vibrations or rapid
temperature changes.
The cover is hooked to the base at the top edge and must be removed from the
bottom edge first. Use a small Phillips screwdriver to loosen the security
screw as shown in Figure 1. Complete removal of the screw is not required. Use
the screwdriver to carefully pry each bottom corner if necessary. Tip the
cover away from the base and sit it aside as shown in Figure 2.
Sit the PCB aside until the base is mounted on the wall. For added protection,
place the PCB in the supplied anti-static bag.
Mount the base by screwing to an electrical box or directly to the wall as
shown in Figure 4. The mounting hole locations are shown on page 7
After the base is screwed to an electrical box or directly to the wall using
the appropriate holes, remove the PCB from the anti-static bag, feed
connection wires through the center hole and place the top of the PCB into the
PCB holders on the backplate and snap the bottom of the PCB into place as
shown in Figure 4.
Making wiring connections as per the Wiring illustrations and install the
decorative cover by placing the top of the cover into the cover holder on the
top of the backplate and snapping the bottom into place as shown in Figure 4.
Tighten the security screw with a Phillips screwdriver.
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 PWR terminal. The supply common is connected to the COM 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 outputs are available on the CO2, RH (If option ordered) and TEMP
terminals. The signal type can be ordered as either voltage or 4-20 mA active
outputs. The voltage model 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
signals are typically connected directly to the Building Automation System
(B.A.S.) and used as control parameters.
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.
If installed, the override switch output is a two-wire dry contact normally
open switch contact. The slide pot output is a two-wire resistive signal that
can vary from 0-10K ohms with left-to-right slide pot action. Other resistive
values are available on request and the slide pot may be configured as normal
or reverse acting.
The override switch and slide pot share a single common labeled S. COM and
this is not connected to the power supply COM.
START-UP
Verify the transmitter is properly wired and connections are tight. The LCD
will indicate the software version number, the relay set-point (if installed),
the CO2 measurement range, the temperature range and then the device will
begin reading the sensor values and display them on the LCD. The sensor will
update the output and display every 4 seconds
OUTPUTS
The CO2 output is scaled so that 4-20 mA (or 0-5/0-10 Vdc) equals 0 to Out
High as set in the Setup Menu. Depending on the range configured in the menu,
the factory default is 0-2000 ppm. The OUT_HIGH can be changed in the Setup
Menu and the output signal is scaled accordingly.
The RH and temperature outputs operate similar to the CO2 output. RH is scaled
0-100 % RH (If option ordered) and temperature defaults to 32 to 95°F but can
be changed to 0 to 35°C, 0 to 50°C or 32 to 122°F using the Setup Menu.
For voltage output models, the factory default is 0-5 Vdc and can be changed
to 0-10 Vdc in the Setup Menu.
OPERATION
The CO2 , RH, and Temperature signals are connected to the Building Automation
System (BAS) analog inputs. The BAS reads the voltage or current signals and
calculates actual values using correct scaling for the ranges and signal type.
These values can be used to control ventilation devices or initiate alarms.
All values are displayed locally on the LCD. The Setup Menu can be used to
modify the displayed information.
This display is factory set to display all measurement values. The CO2 level
will continuously be displayed, while the RH (if RH option ordered) and Temp
will alternate. The CO2 level will be displayed as 0-2000 ppm to 10,000ppm
depending on configuration setup, the %RH will be displayed as 0-99H and the
temperature will be displayed as 0 to 50°C. The Setup Menu can be used to
modify the displayed information. The installer can select to only display
CO2, or to display CO2 and RH, or alternately CO2 and temperature. The device
supports four temperature ranges that may also be selected in the menu. The
default is 0 to 50°C but this may be changed to 0 to 35°C and the output
signal will stay the same. Also, the temperature range may be changed to 32 to
95°F or 32 to 122°F by changing the Temp Scale setting from C to F and the
output scaling will change to match the display.
If the optional relay is installed it can directly control a small fan or
alarm by setting the trip value and hysteresis to appropriate values. The
relay status is not indicated on the device LCD.
The optional override switch provides a dry contact closure to a digital input
of the BAS. The switch status is not indicated on the LCD.
The optional slide pot can be connected to an analog input of the BAC and will
provide a linear resistance signal such as 0-10 KΩ (for example) to be used as
a set-point control. The set-point value is not shown on the LCD.
CALIBRATION
The RH and temperature measurements typically do not need any calibration for
the life of the product.
Both values may have user offsets assigned in the Setup Menu.
CO2 calibration with gas requires a field calibration kit with pressure
regulator, necessary tubing and appropriate bottles of CO2 gas. The model
requires only a single point 1000 ppm calibration to meet specified accuracy
1000 PPM CALIBRATION
Connect the 1000 ppm CO2 gas bottle to Regulator and Tubing with calibration
hood. Place hood over CO2 sensor flush with PCB and apply the gas. The CO2
reading on the LCD will begin to approach 1000 ppm. Wait 1 to 2 minutes while
the CO2 reading stabilizes.
Enter the Setup menu and use the