Trane N512, Zone Controller, CNT-SVX07C-EN manual Fan does not energize, Probable cause Explanation

Chapter 7

Troubleshooting

Use Table 17 through Table 22 to assist you in diagnosing any of the fol- lowing operational problems that you might encounter with the Tracer ZN521 zone controller:

•Fan does not energize (Table 17)

•Valves remain closed (Table 18 on page 64)

•Valves remain open (Table 19 on page 65)

•Compressors are not running (Table 20 on page 65)

•Electric heat does not energize (Table 20 on page 65)

•An outdoor air damper stays closed (Table 21 on page 66)

•An outdoor air damper stays open (Table 22 on page 66)

Table 17. Fan does not energize

Probable cause	Explanation
Unit wiring	The wiring between the controller outputs and the fan relays and contacts must be
	present and correct for normal fan operation. Refer to applicable wiring diagram.
Failed end device	The fan motor and relay must be checked to ensure proper operation.
Normal operation	The fan will turn off when the controller receives a communicated off signal, when the
	fan-speed switch is set to OFF, when specific diagnostics are generated, or when the
	default fan speed is set to Off and the fan is operating in the Auto mode. If the controller
	is in unoccupied mode, the fan cycles between off and the highest fan speed.
No power to the con-	If the controller does not have power, the unit fan does not operate. For the Tracer ZN521
troller	controller to operate normally, it must have an input voltage of 24 Vac. If the green LED is
	off continuously, the controller does not have sufficient power or has failed.
Power-up control-wait	If power-up control-wait is enabled (non-zero time), the controller remains off until one of
	two conditions occurs:
	1) The controller exits power-up control-wait after it receives communicated information.
	2) The controller exits power-up control-wait after the power-up control-wait time expires.
Diagnostic present	Several diagnostics affect fan operation. For information about these diagnostics, see
	Table 16 on page 59.
Unit configuration	The controller must be properly configured based on the actual installed end devices and
	application. If the unit configuration does not match the actual end device, the fans may
	not work correctly.
Manual output test	The controller includes a manual output test sequence you can use to verify output oper-
	ation and associated output wiring. However, based on the current step in the test
	sequence, the unit fan may not be on. Refer to the “Manual output test” on page 52.
Random start	After power-up, the controller always observes a random start from 5 to 30 seconds. The
observed	controller remains off until the random start time expires.

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