Input/Output Functions And Wiring For Typical Applications; Binary Inputs - Trane Tracer ZN521 Installation And Operation Manual

Input/output functions and wiring for typical
applications
This chapter provides information about the function of inputs and outputs and examples of wiring
for typical applications. Applications supported by the Tracer ZN521 zone controller are shown in
Table
Table 2. Typical applications for the Tracer ZN521 zone controller
Application
2-pipe hydronic cooling only
2-pipe hydronic heating only
2-pipe changeover
2-pipe steam only
4-pipe hydronic heating and cooling
4-pipe changeover
4-pipe steam/chilled water
Electric heat only (single- and two-stage)
DX/hydronic heating
DX/steam heating
DX cooling only
Figures
all required and all optional components for typical applications.

Binary inputs

The Tracer ZN521 controller includes four binary inputs. Each binary input associates an input
signal of 0 Vac with open contacts and 24 Vac with closed contacts. You can use the Rover service
tool to configure each of the inputs as normally open or normally closed. If an application does not
warrant the use of a particular input, configure the input as Not Used. This will disable the
generation of diagnostics for this function.
Table 3
Table 3.
CNT-SVX07D-EN
2.
x
x
x
x
x
x
x
x
x
Step 7 through Step 17
gives the function of each binary input.
Binary inputs
Binary input
terminal label
Low-coil-temperature detection
BI1
Condensate overflow
BI2
x
x x
x x x
x x
x x x
x x x
x
x
x
(pages 20 through 30) show typical wiring diagrams that include
Function
x x x
x x x
x x x
x x x
x x x
x x x
x x x
x x
x x x
x x x
x x
x
x
×
x
13