Binary inputs

BI3: Occupancy or generic binary input

The BI3 binary input can function as either:

The occupancy input

A generic binary input

The function of occupancy is to save energy by spreading zone setpoints when the zone is unoccupied. As the occupancy input, BI3 can be used for two related functions. For stand-alone controllers, BI3 can be hard-wired to a binary switch or timeclock to determine the occupancy mode—either occupied or unoccupied. For controllers receiving a BAS-communicated occupancy request, the function of BI3 is to change the mode from occu- pied to occupied standby. (For more information on occupancy-related functions, see “Occupancy modes” on page 36.)

BI3 is the only binary input that can be configured as generic. If config- ured as a generic binary input, it can be monitored by a BAS and has no direct effect on Tracer ZN521 operation.

BI4: Fan status

The fan status input provides feedback to the controller regarding the fan’s operating status. If BI4 is wired to a fan status switch and the input indicates that the fan is not operating when the controller has the fan controlled to on, the controller will generate a Low AirFlow—Fan Failure diagnostic. (For more information, see “Fan status” on page 49.)

CNT-SVX07C-EN

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Trane N512, Zone Controller, CNT-SVX07C-EN manual BI3 Occupancy or generic binary input, BI4 Fan status