Trane UNT-SVX07A-EN manual Maintenance diagnostics, Table M-D-1. Tracer ZN520 Diagnostics

Maintenance diagnostics

Diagnostics

Table M-D-1. Tracer ZN520 Diagnostics

Diagnostic	Fan	Other Outputs (Note 1)
Condensate overflow	Off	Valves Closed, Fresh air damper Closed, electric heat Off,
		Baseboard heat Off
Low temperature detection	Off	Valves Open, Fresh air damper Closed, electric heat Off,
		Baseboard heat Off
Low air flow - fan failure	Off	Valves Closed, Fresh air damper Closed, electric heat Off,
		Baseboard heat Off
Space temperature failure	Off	Valves Closed, Fresh air damper Closed, electric heat Off,
		Baseboard heat Off
Entering water temp failure	On	Valves Enabled (Note 2), Fresh air damper Enabled (Note 2),
		electric heat Enabled (Note 2), Baseboard heat Off
Discharge air temp low limit	Off	Valves Open, Fresh air damper Closed, electric heat Off,
		Baseboard heat Off
Discharge air temp failure	Off	Valves Closed, Fresh air damper Closed, electric heat Off,
		Baseboard heat Off,
Fresh air temp failure	On	Valves Enabled, Fresh air damper Minimum position3, electric
		heat Enabled, Baseboard heat Enabled
Relative humidity failure	On	Valves Enabled, Fresh air damper Enabled, electric heat
		Enabled, Baseboard heat Enabled
Generic 4-20ma failure	On	Valves Enabled, Fresh air damper Enabled, electric heat
		Enabled, Baseboard heat Enabled
CO2 Input failure	On	Valves Enabled, Fresh air damper Enabled, electric heat
		Enabled, Baseboard heat Enabled
Maintenance required	On	Valves Enabled, Fresh air damper Enabled, electric heat
		Enabled, Baseboard heat Enabled
Local fan mode failure	On	Valves Enabled, Fresh air damper Enabled, Electric Heat
		Enabled, Baseboard heat Enabled
Local setpoint failure	On	Valves Enabled, Fresh air damper Enabled, electric heat
		Enabled, Baseboard heat Enabled
Invalid unit configuration	Off	Valves Disabled, Fresh air damper Disabled, electric heat
		Disabled, Baseboard heat Disabled
Normal – power up	On	Valves Enabled, Fresh air damper Enabled, Electric heat Enabled

Note 1: The generic binary output (TB4-1, TB4-2) state is unaffected by all unit diagnostics.

Note 2: When the entering water temperature is required but not present, the Tracer ZN520 controller generates a diagnostic to indicate the sensor loss condition. The controller automatically clears the diagnostic once a valid entering water temperature value is present (non-latching diagnostic). When the entering water temperature sensor fails, the controller prohibits all hydronic cooling operation, but allows the delivery of heat when heating is required. In the Cool mode, all cooling is locked-out, but normal fan and outdoor air damper operation is permitted.

Note 3: When the outdoor air temperature sensor has failed or is not present, the Tracer ZN520 controller generates a diagnostic to indicate the sensor loss condition. The controller automatically clears the diagnostic once a valid outdoor air temperature value is present (non-latching diagnostic). When the outdoor air temperature sensor fails or is not present, the controller prohibits economizer operation.

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