Trane CNT-SVX07C-EN, Zone Controller Wiring requirements and options, Overriding binary outputs

Chapter 4 Input/output functions and wiring for typical applications

Overriding binary outputs

The Tracer ZN521 controller includes a manual output test and a water valve override feature. Use the manual output test to manually control the outputs in a defined sequence. For information, see “Manual output test” on page 52.

The water valve override feature is a procedure used for water balancing.

Using the Rover service tool or a BAS, a user can specify that a Tracer

ZN521 override the state of water valves to:

•Open all valves

•Close all valves

The controller resets itself to normal operation after two hours.

Wiring requirements and options

Table 7 shows required controller inputs for minimal proper operation of all applications.

Table 7. Required controller inputs for proper operation

Function	Input source	For more information,
		see:
24 Vac power	Terminals: GND, 24 V	“AC-power wiring” on
		page 7
Zone temperature	Terminals: ZN, GND	“ZN: Zone tempera-
	or communicated	ture” on page 16
Discharge air temperature	Terminals: AI2	“AI2: Discharge air tem-
		perature” on page 18
Entering water tempera-	Terminal: AI1	“AI1: Entering water
ture—required only for	or communicated	temperature” on
units with auto		page 17
changeover
Outdoor air temperature—	Terminals: AI3 or	“AI3: Outdoor air tem-
required only for econo-	communicated	perature or generic
mizing		temperature” on
		page 18
Relative humidity—	Terminals: AI4	“AI4: Universal 4–
required only for dehu-		20 mA” on page 19
midification

Figure 7 on page 23 through Figure 17 on page 33 show typical applica- tions that include all required and all optional components.

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