Filter
Top Products
Chapter 4 Input/output functions and wiring for typical applications
16 CNT-SVX07C-EN
Analog inputs
The Tracer ZN521 controller includes seven analog inputs. Table 4
describes their functions. Each function is explained in the following
paragraphs. For an explanation of the diagnostics generated by each ana-
log input, see “Diagnostics” on page 58. For more information about how
the controller operates, see Chapter 5, “Sequence of operations”
GND: Ground terminals
Use a GND terminal as the common ground for all zone sensor analog
inputs.
ZN: Zone temperature
The ZN analog input functions as the local (hard-wired) zone temperature
input. The controller receives the temperature as a resistance signal from
a 10 kΩ thermistor in a standard Trane zone sensor wired to analog input
ZN. A zone temperature value communicated by means of a LonTalk link
can also be used for controllers operating on a BAS. When both a hard-
wired and communicated zone temperature value is present, the control-
ler uses the communicated value. If neither a hard-wired nor a communi-
cated zone temperature value is present, the controller generates a Zone
Temp Failure diagnostic.
The ZN analog input is also used to communicate timed override requests
and cancel requests to the controller for applications using a Trane zone
sensor with
ON and CANCEL buttons.
Table 4. Analog inputs
Analog input
terminal label
Function
ZN Zone temperature
GND Zone sensor common ground
SET Local setpoint
FAN Fan mode input
GND Auxiliary ground
AI1 Entering water temperature
AI2 Discharge air temperature
AI3 Outdoor air temperature or generic temperature
AI4 Universal 4–20 mA