Page 28
Room Sensors
Room sensor (A2) is a two-wire thermistor with 1k series resistor.
TABLE 2
Two-Wire Thermistor
Temp. °F (°C) Resistance +/-2% Temperature °F (°C) Resistance +/-2% Temp. °F (°C) Resistance +/-2%
40 (4.4) 27,102 60 (15.6) 16,313 80 (26.7)
45 (7.2) 23,764 65 (18.3) 14,474
50 (10) 70 (21.1) 12,882
55 (12.8) 18,433
Carbon Dioxide Sensor
The indoor carbon dioxide sensor (A63) is an analog sensor with a 0-10VDC output over a carbon dioxide range of 0-2000
ppm as shown in the following table. The sensor is powered with 24VAC.
TABLE 3
Carbon Dioxide Range
Carbon Dioxide
PPM
DCV
Carbon Dioxide
PPM
DC Voltage Carbon Dioxide
PPM
DC Voltage Carbon Dioxide
PPM
DCV
0
0 600
3 1200 6 1800
200
1 800
4 1400 7 2000 10
400
2 1000
5 1600 8
VAV Supply Static Sensor
0-5”w.c as shown in the following table. The sensor is powered with 24VAC.
TABLE 4
Static Pressure
Pressure “w.c. DCV Pressure “w.c. DC Voltage Pressure “w.c. DC Voltage Pressure “w.c. DCV
0
0 1.5
3 3 6 4.5
0.5
1 2
4 3.5 7 5 10
1
2 2.5
5 4 8
Relative Humidity Sensor - Optional
sensor with a 0-10VDC output over a relative humidity
range of 0-100% relative humidity. The sensor is powered
with 24VAC.
Enthalpy Sensor - Optional
The optional enthalpy sensors (A7 and A63) used with
the economizer have an output of 4-20mA. The sensor is
powered with 18VAC provided by M3 unit control.
Pressure Transducer (PT5) present in the economizer.
PT5 requires 5VDC power supply (P266-5 and {P266-
6) and gives 0.25 VDC to 4 VDC output (P266-4) corre-
sponding to 0” water column and 2” water column respec-
tively. For all practical purposes the output should be less
than 1.2” water column if not an error code is stored and
service alarm output is turned on.
To Next Page
Loading...
