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Premium Commercial Controls
ERV
24
UNIT CONFIGURATION
Field-installed control sensors and monitors are to be installed and wired in accordance with
instructions shipped in the documentation package. Wire gauge must be in accordance with
the following:
Wire Gauge
#22
#20
#18
#16
#14
#12
Circuit Length
100'
150'
250'
400'
700'
1000'
4.2.4 CO2/VOC Sensors
The ERV control allows the use of a CO2 sensor and/or a VOC sensor. The sensor may be
physically attached to the system (Source = Hardware) or the value may be written from the
BMS system (Source = from BMS).
The CO2 sensor is used as part of a demand control ventilation system to provide speed control
of fans based on the level of CO2 in the space or duct. These sensors provide a 0–10VDC signal
scaled as specified in the CO2 scaling screen.
FIGURE 4.2.1 CO2 SENSOR (DUCT MOUNT, SIDE VIEW)
FIGURE 4.2.2 CO2 SENSOR (WALL MOUNT)
The Air Quality Monitor detects total VOCs (TVOC) in the supply airstream or the space. It uses
a MEMs metal oxide semiconductor sensor to capture VOC emissions that are invisible to CO2
sensors. It is installed in the SA duct or the space. These sensors provide a 0–10VDC signal
scaled as specified in the VOC scaling screen.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
with offset
no offset
19.2 K
9.6 K
38.4 K
57.6 K
CAREL
Modbus
ON
OFF
Address
Ext.
Prot
Baud
Address
Ext Baud Prot
EXPANSION MODULE
X3-27
X3-22
X3-21
CO2-W OR CO2-D SENSOR
P/N 131304 OR 131305
NOTE: When wiring
sensor, do not wire
directly to the
expansion module;
wire to the X3 terminal
block, see Figure 4.2.0.
