Gnd: Ground Terminals; Zn: Zone Temperature; Set: Local Setpoint; Fan: Fan Mode Input - Trane Tracer ZN521 Installation And Operation Manual

by each analog input, see
operates, see
Table 4.

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 controller uses the communicated value. If
neither a hard-wired nor a communicated 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

SET: Local setpoint

The SET analog input functions as the local (hard-wired) temperature setpoint input for
applications utilizing a Trane zone sensor with a temperature setpoint thumbwheel. The local
setpoint input is configurable (as enabled or disabled) using the Rover service tool. A setpoint value
communicated by means of a LonTalk link can also be used for controllers operating on a BAS. If
both hard-wired and communicated setpoint values are present, the controller uses the
communicated value. If neither a hard-wired nor a communicated setpoint value is present, the
controller uses the stored default setpoints (configurable using the Rover service tool). If a valid
hard-wired or communicated setpoint value is established and then is no longer present, the
controller generates a Setpoint Failure diagnostic.

FAN: Fan mode input

The FAN analog input functions as the local (hard-wired) fan mode switch input for applications
using the Trane zone sensor with a fan mode switch option. The various fan mode switch positions
(off, low, medium, high, auto) provide different resistances that are interpreted by the Tracer ZN521.
The local fan mode switch input is configurable (as enabled or disabled) using the Rover service
tool. A communicated fan mode request via the LonTalk communications link can also be used for
controllers operating on a BAS. If both hard-wired and communicated fan mode values are present,
the controller uses the communicated value. If neither a hard-wired nor a communicated fan mode
value is present, the controller recognizes the fan mode value as auto and operates according to
CNT-SVX07D-EN
Input/output functions and wiring for typical applications
"Diagnostics, " p.
"Sequence of operations, " p. 31
Analog inputs
Analog input
terminal label
Zone temperature
ZN
Zone sensor common ground
GND
Local setpoint
SET
Fan mode input
FAN
Auxiliary ground
GND
Entering water temperature
AI1
Discharge air temperature
AI2
Outdoor air temperature or generic temperature
AI3
Universal 4–20 mA
AI4
48. For more information about how the controller
Function
and
ON
buttons.
CANCEL
15