Analog inputs for 1 heat/1 cool applications
CNT-SVX06B-EN 37
AI1: Entering water temperature sampling
The AI1 analog input functions as the local (hardwired) entering water
temperature sampling input for 1 heat/1 cool applications. An entering
water temperature communicated via the LonTalk communications link
can also be used for controllers operating on a BAS. If both a hardwired
and a communicated entering water temperature value is present, the
controller uses the communicated value. If a valid hardwired or communi-
cated entering water temperature value is established and then is no
longer present, the controller generates an Entering Water Temp Failure
diagnostic.
For units configured as 2-pipe or 4-pipe changeover units, the entering
water temperature is used to make heat/cool operation decisions. If nei-
ther a hardwired nor a communicated entering water temperature value
is present on changeover units, the controller will operate in heating
mode only, assuming the water is hot.
For units not configured as changeover units, entering water temperature
sampling is used for information and troubleshooting only and does not
affect the operation of the controller.
AI2: Discharge air temperature
The AI2 analog input functions as the local (hardwired) discharge air
temperature input. The discharge air value is used for information and
troubleshooting only and does not affect the operation of the controller.
The controller receives the temperature as a resistance signal from a
10 kΩ thermistor wired to analog input AI2. A discharge air temperature
value communicated via the LonTalk communications link can also be
used for controllers operating on a BAS. If a valid hardwired or communi-
cated discharge air temperature value is established and then is no
longer present, the controller generates a Discharge Air Temp Failure
diagnostic.
Note:
Neither AI1 nor AI2 is polarity sensitive; you can connect either
terminal to either sensor lead.
Note:
Neither AI1 nor AI2 is polarity sensitive; you can connect either
terminal to either sensor lead.
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