Trane LO manual Unit Mode Listed as Standby, Cycling Power to the TUC, Terminal Unit Control TUC

Terminal Unit Control (TUC)

Cycling Power to the

TUC

Using Tracer 100i™ or 100L™

Using Tracer Summit®

Unit Mode Listed as Standby

Remove the 24 VAC power from the board and then reapply it to cycle the unit through a power-up sequence. By default, the controller attempts to reset all diagnostics at power-up.

The TUC editor’s reset failure point allows the user to reset controller diagnostics. Also, Tracer® versions 14.4 and higher provide a “+ enter” option from the TUC service summary screens that allow latching diagnostic reset.

When using a Tracer Summit® system, reset the unit diagnostics with the reset diagnostics button on the TUC editor screen.

The unit’s operating machine state is in standby when one of the following conditions occurs:

1.Tracer® override is present.

2.During the power-up sequence or any time when the TUC is calibrating its end devices.

3.When the TUC is in the unoccupied mode and there is no call for heating or cooling.

4.In the occupied mode when the desired capacity is unavailable.

ie: the TUC requests a 2-pipe unit to heat, yet no hot water or electric heat is available. The TUC will list the unit as being in standby mode.

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