ETC echoflex RCT User manual

Page Page1 RTC CO2, Temperature and Humidity Sensor Configuration Guide
Wireless CO2, Humidity and temperature sensor
rCt Detailed Installation and
Commissioning Guide
Copyright © 2019 Echoex Solutions, Inc.
All rights reserved. Product information and specication details subject to change
Document number: 8DC-5771 Rev: 1.2 Released: 2019-05

Page 2
Echoex intends this document, whether printed or electronic, to be read
in its entirety.

Page 3 RTC CO2, Temperature and Humidity Sensor Configuration Guide
Table of Contents
Overview 1
Document Conventions�������������������������������������������������������������������� 1
The RCT CO2 Sensor ������������������������������������������������������� 2
Radio Communications �������������������������������������������������������������������� 2
Receiver Proximity ��������������������������������������������������������������������������� 2
Performing a CO2 Background Calibration ���������������������� 3
Reading the CO2Concentrations ������������������������������������ 4
Light Harvesting Transmitter Description������������������������ 5
COLED Indication ���������������������������������������������5
An example of determining exact CO2value from blink code: ������� 6
 7
Linking the RCT Sensor to a Receiver������������������������������� 8
Using The Adjustment and Test Functions����������������������� 8
 10
Light Level Test������������������������������������������������������������� 10
LIGHT LEVEL TEST TABLE ���������������������������������������������������������������� 10
����������������������������������������� 11
Automatic Background Calibration Activation�������������� 11
���������������������������������� 11
Guidelines for Installing Wireless Devices 14
Wireless System Layout Hints ��������������������������������������� 15
 16
Agency and Regulatory Statements ������������������������������ 17

Table of Contents Page 4

Page 1 RTC CO2, Temperature and Humidity Sensor Configuration Guide
Overview
The CO2 sensor (also referred to as the sensor in this guide) is a
wireless, energy harvesting sensor that :
• monitors CO2 levels from 0-2000 ppm,
• room temperature in the range of 0-51°C (32°F to 124°F) and
• relative humidity in the range of 0-100% .
The CO2 measurement is also automatically altitude corrected
using a sensitive (± 3ft) absolute pressure sensor. The device comes
populated with a CR2032 coin cell battery to provide backup power
for up to 5 years of operating time. The product is designed to
operate with 3rd party receivers, controllers and gateways designed
for EnOcean compatible wireless networks. The sensor is intended
for indoor use only.
A button on the lower right edge of the sensor body can be used
to cause the LED’s to blink a code that indicates CO2concentration
or to go into test mode (when the button is held down, see “Test
Operating Modes”).
Document Conventions
This document includes the following conventions to draw attention
to important information.
iNote: Notes are helpful hints or information that supplement
the main content.
Echoex's user documentation is designed for print or electronic
use. Benets to using the electronic format include using the table
of contents to jump to a desired page by clicking on the heading or
using word search to nd a specic topic.
Cross references highlighted in this document are links to the
referenced section of the guide.
. This guide is available for free download from Echoex Solutions
website: www.echoexsolutions.com

Overview Page 2
The RCT CO2 Sensor
The RTC is specically designed for building systems where indoor
environmental quality and potential savings from utilizing CO2based
demand controlled ventilation is desired.
The RTC is a versatile, wireless CO2, temperature and humidity
transmitter that operates based on energy harvested from indoor
ambient light. The sensor has no wires, requires no maintenance
and can be easily installed and integrated into an EnOcean® wireless
network. This sensor platform is ideal for EnOcean® networks
installed in new or existing buildings. EnOcean is an open, wireless
protocol that allows integration with a variety of other products and
systems.
Batteries are not required for everyday operation due to the
advanced solar energy harvesting and power management features
of the sensor. There is a clip for a coin cell battery (battery provided)
to aid in quick installation and to provide extended backup in no
light or low light conditions. The sensor will operate under battery
power for over ve years.
iNote:
Tricolored LEDs provide indications to aid with
installation as well as a means of displaying current CO2
levels at the push of a button.
Radio Communications
The RTS is a wireless device capable of transmitting telegrams.
The sensor transmits status telegrams that contain the information
dened within a equipment prole.
The sensor supports the following proles:
A5-09-04: CO2Sensor + Temperature Sensor + Humidity Sensor
The valid ranges for each data element:
CO2: 0 - 2000 ppm
Temperature: 0 - 51°C, (32° - 124°F)
Humidity Sensor: 0 -100% RH
Receiver Proximity
The sensor transmits to a receiver which is typically a device that is
programmed to provide HVAC ventilation and temperature control in
the space that the sensor is monitoring for closed loop temperature
control. The sensor and receiver must be within range, preferably
in the same room and installed within 50’ (15.2 m) of each other.
For applications exceeding 50’ (15.2 m) range, greater care must be

Page 3 RTC CO2, Temperature and Humidity Sensor Configuration Guide
taken to insure proper reception of the sensors transmissions at the
receiver, refer to sections “Test Operating Modes” and ‘Installing
Wireless Devices”.
iNote:
The RCT comes populated with a CR2032 coin cell battery.
The battery is not required for normal operation when
the RCT receives adequate natural or articial light. The
battery is required for calibration.
iNote:
Even with a brief exposure to light the sensor will operate,
however for best results the sensor should be mounted in
a location with exposure to 4 hours of natural or articial
light on a daily basis.
Performing a CO2 Background Calibration
It is highly recommended that the installer perform an ambient air
calibration of the RCT as part of the installation process. The sensor
will take the lowest CO2 recorded since its last calibration cycle and
assign this reading the value of 420ppm (outdoor air). This process
takes 15-60 minutes and can be performed on-site or prior to visiting
the site. Multiple sensors can be calibrated at the same time. Further
instructions on other adjustments that can be made can be found
on page 10
1) Place the sensor(s) in outside air above 32ºF (0ºC), and out of
direct sunlight for 15 to 60 minutes. Avoid areas where people are
lingering so the background CO2 readings are not affected. The
sensor will take the lowest CO2 recorded since its last calibration
cycle and assign this reading the value of 420ppm (outdoor air).
2). Press the function button on the sensor until the green LED is
blinking, about 6 seconds.
3.) Tap the function button to cycle through modes. Once the Red
LED (only) is blinking, press and hold for ~ 6 seconds to enter CO2
background calibration mode, there will be a pause then the Green
LED will begin blinking.
4). After about 6 seconds the green LED will stop blinking when
calibration is complete.
Install the sensor in the targeted location and connect to an
EnOcean network.
There is also an option to set a specic value for the CO2sensor to
calibrate to. The process for doing this is explained in detail later in
this guide. It is important to note that any calibrations should be
done so that the air around the sensor is at the concentration to be
used for calibration. Flowing calibrated gas through a tube to the

Overview Page 4
inside of the sensor is not a valid or accurate method of calibration.
For commissioning purposes, the best way to evaluate the sensor is
to compare the sensor to a hand held CO2 sensor that has recently
been calibrated at approximately the same altitude (± 500 ft).
Reading the CO2Concentrations
The RCT does not have a digital display but it is possible to
1. Quickly determine the general range of CO2 concentration in
the space and
2. Determine the actual concentrations in the space.
Current CO2 range is indicated by an LED blink every 15 seconds.
Green LED: < 1100 ppm (good)
Amber LED: 100 to 1500 ppm (marginal)
Red LED: > 1500 ppm (poor ventilation)
Acquiring current CO2 concentration:
• Press function button on lower right side for 1 second.
• Count LED blinks, add together for current level:
Green = 500 ppm
Amber = 100 ppm
Red = 25 ppm
See example on page 6
Red LED
Amber LED
Green LED
Solar Panel
RCT Sensor - Reading the CO Level
Current Range:
Indicated by an LED blink every 15 seconds
• Green (lower LED): < 1,100 ppm (Good)
• Amber (middle LED): 1,100 to 1,500 ppm (marginal)
• Red (upper LED): > 1,500 ppm (poor ventilation)
Current Concentration
1. Press button on lower right side for 1 second
2. Count LED blinks (and add) for current CO2
concentration
• Green blink = 500 ppm
• Amber blink = 100 ppm
• Red blink = 25 ppm
2
CO2
CO2

Page 5 RTC CO2, Temperature and Humidity Sensor Configuration Guide
Light Harvesting Transmitter Description
In order to best manage power, the transmitting interval of the RCT
is automatically managed dependent on ambient light levels, rate of
measurement change and amount of power stored in the sensor.
Telegrams are sent at the following intervals:
• If the temperature change between last transmitted value and
the current sample is > 0.6°C (1.1°F), the sensor will transmit
immediately.
• If the RH value change between last transmitted value and the
current sample is > 3%, the sensor will transmit immediately.
• If the CO2 value change between samples is > 200 ppm, the
sample and heartbeat rate shall adjust to 300 sec (5 min) for 1
sample period
• The CO2 sample rate value is derived from three consecutive
readings from the COZIR sensor averaged with the previous
transmitted value, level 1 and 2 only. For level 3, only the 3
readings taken during the current sample are averaged.
Ambient Light Temp/RH
Sampling Rate
CO2 sampling
Rate
Heartbeat Rate
> 200 lux (18.5 fc) 16 sec 300 sec (5 min) 300 sec (5 min)
< 200 lux (18.5 fc) 32 sec 600 sec (10 min) 600 sec (10 min)
<50 lux for 16 hours 64 sec 1200 sec (20 min) 1200 sec (20 min)
CO2LED Indication
There are 3 LEDs located on the right side of the solar panel. The RCT
will provide an indication of the current CO2 measurement range by
ashing every 15 seconds (with sufcient light, > 5 footcandles or 50
lux). Ranges indicated by the ash are as follows:
• Green = < 1100 ppm (Good ventilation/air
quality)
• Yellow = 1100-1,500 ppm (marginal
ventilation/air quality)
• Red = >1,500 ppm (low ventilation &
potentially poor air quality)
2,600
2,400
2,200
1,800
1,600
1,400
1,200
1,000
800
600
400
5
6
8
10
15
20
25
30
Ventilation Rate (cfm/person)
Poor
Under
Ventilated
Marginal
Unacceptable
Outside
Levels
Indoor
Optimal
CO Concentration
2

Installation Page 6
iNote: These LEDs are also used as feedback for the Test
functions
To determine the exact CO2 value, press the function button on
the side of the unit. The LEDs will ash in sequence to indicate the
concentration where:
• Green blinks = 500 ppm/blink
• Amber blinks = 100 ppm/blink
• Red blinks = 25 ppm/blink
Add the blink values up to determine the concentration.
An example of determining exact CO2value from blink
code:
• 2 green blinks = 1000 ppm
• 3 amber blinks = 300 ppm
• 2 red blinks = 50 ppm
• Total CO2 = 1350 ppm
• The colored chart is a guideline for mapping the CO2
concentration and how this value reects on the spaces
ventilation rate.