Terminal Unit Control (TUC)
BIP4: Smoke Input
BIP3: Occupied/ Unoccupied Mode
and the electric heat to disable. This creates an immediate shutdown latching diagnostic, which requires a manual or Tracerâ reset to resume normal operation.
However, normal operation cannot resume until the water level recedes to an acceptable level. The switch will close after the water level recedes, and the active temperature control of the unit will resume by an automatic reset. Since both the condensate overflow detection and occupied/unoccupied status occupy BIP3 on the TUC board, only one option can be in use. The factory configures the 24V dry contact input as normally closed to indicate an alarm. However, it also can be normally open if using the correct switch.
The smoke input is a binary input on the TUC that is used with a smoke detector switch (installer supplied) to signal an alarm. Config- ure the input to either send an alarm to Tracer® or as a shutdown latching diagnostic. If the input is configured as a shutdown latching diagnostic, the TUC closes the control valve(s), shuts the fan off, closes the fresh air damper, and disables electric heat.
If the input is configured to send an alarm, Tracer will issue a system wide shutdown for the building. The unit will continue to run, and no diagnostic will register within the TUC. The factory configures the
24V dry contact input as normally closed. However, it can also be normally open if using the correct switch.
The unit can operate in the occupied/unoccupied mode when a binary signal is input from an external source such as a time clock or Tracer® . Reference the “TUC Fan Mode Operation” section on page 65 for the sequence of operations. This option is only available if the condensate overflow input is not in use (if not using Tracer®), since both inputs occupy the same point on the TUC board. The factory configures the 24V dry contact input as normally closed. However, it can also be normally open if using the correct switch. A closed signal indicates occupied mode.
BIP1: External Interlock
The external interlock input allows the unit to be remotely stopped when a binary signal is input to the TUC from an external source or from Tracer®. Since both external interlock and condensate overflow input to the same point (if not using Tracer®) on the TUC board, only one input can be in use. The factory configures the 24V dry contact input as normally closed, but it can also be open if using the correct switch.
98 |
