sequence of
Operation operation
Note: If the unit is in the unoccupied mode, the dehumidification routine will not operate.
Data Sharing
Because this controller utilizes LonWorks™ technology, the controller can send or receive data (setpoint, heat/ cool mode, fan request, space temperature, etc.) to and from other controllers on the communication link, with or without the existence of a building automation system. This applies to applications where multiple unit controllers share a single space temperature sensor (for rooms with multiple units but only one zone sensor) for both standalone (with communication wiring between units) and building automation system applications. For this
Note: The generic binary input can be used with a Tracer Summit® building automation system only.
Each binary input default configuration (including normally open/closed) is set at the factory. However, you can configure each of the four binary inputs as normally open or normally closed. The controller will be set properly for each factory- supplied binary input
Binary Outputs
Binary outputs are configured to support the following:
•Three fan stages (when one or two fan stages are present, medium fan speed can be configured as exhaust fan)
•One hydronic cooling stage
•One hydronic heating stage (dehumidification requires this to be in the reheat position)
•One DX cooling stage
•One or
•Face and bypass damper
•Modulating outdoor air damper
•One baseboard heat stage
For more information, see Table
application you will need to use the Rover service tool. For more information on setup, refer to the Trane publication
Binary Inputs
The Tracer ZN520 controller has four available binary inputs. See Table
12.Normally, these inputs are factory- configured for the following functions:
• Binary input 1: Low temperature detection (freezestat)
• Binary input 2: Condensate overflow
• Binary input 3: Occupancy/ Generic
• Binary input 4: Fan status
Table O-SO-12. Binary input configurations
binary |
|
| controller operation | |
input | description | configuration | contact closed | contact open |
BI 1 | low temperature detection Note 1 | normally closed | normal | diagnostic Note 5 |
BI 2 | condensate overflow Note 1 | normally closed | normal | diagnostic Note 5 |
BI 3 | occupancy | normally open | unoccupied | occupied |
BI 3 | generic binary input | normally open | normal Note 3 | normal Note 3 |
BI 4 | fan status Note 1 | normally open | normal | diagnostic Note 4 |
Note 1 During low temperature, condensate overflow, and fan status diagnostics, the Tracer ZN520 control disables all normal unit operation of the fan, valves, and damper. Note 2The occupancy binary input is for standalone unit controllers as an occupied/unoccupied input. However, when the controller receives a communicated occupied/unoccupied request, the communicated request has priority over the hardwired input. Note 3 The generic binary input does not affect unit operation. A building automation system reads this input as a generic binary input. Note 4 If the fan mode input is in the off position or the controller is in the unoccupied mode with the fan off, the fan status input will be open. A diagnostic will not be generated when the controller commands the fan off. A diagnostic will only be generated if the fan status input does not close after one minute from energizing a fan output or any time the input is open for one minute. The controller waits up to one minute after energizing a fan output to allow the differential pressure to build up across the fan. Note 5 The table below shows the controller’s response to low temperature detection, condensate overflow, and fan status diagnostics.
Table O-SO-13. Binary output configuration
binary output | configuration |
fan high | |
fan medium | |
fan low | |
(Key) | |
cool valve – open, or | |
cool valve – close Note 1 | |
heat valve – open, or 2 position valve, or 1st electric heat stage Note 1 | |
heat valve – close or 2nd Electric heat stage Note 1 | |
fresh air damper - open | |
fresh air damper - close | |
generic / baseboard heat output | |
24VAC |
For Tracer ZN520 units configured and applied as
57 |
