Trane Direct-Fired Indoor and Outdoor Make-Up Air Units Functions, 100% Outside Air, Freezestat

Functions

100% Outside Air

The 100% Outside Air function automatically opens the outside air dampers and closes the return air dampers. This function is activated whenever a contact is closed between the appropriate terminals on the unit's terminal strip located in the unit's main control panel. See the Typical Wiring Schematic and Multiplexed Input sections of this manual for more information. The 100% Outside Air function overrides all other damper control functions. See User Configured PID Control for use with non-recirculating units.

Minimum Ventilation

To change the Minimum Ventilation requires the use of a BACview or PC. The Minimum Ventilation function defines the minimum outside air percentage and automatically prevents the dampers from modulating below this point. This function can be used in heating or cooling mode. If the unit served by this control is a direct-fired heater, that recirculates air before the burner, and is operating in the heating mode, the unit will automatically keep the minimum outside air at 20%. If the outside air drops below 20%, the burner will cycle off. To specify the Minimum Ventilation scroll through the menu tree, locate the Setpoints branch and select Min Vent, and enter the desired outside air percentage. The allowable range is 0% - 100% outside air.

Freezestat

To change the Minimum Ventilation requires the use of a BACview or PC. The Freezestat function automatically cycles the unit off if the supply air temperature drops below the Freezestat setpoint for 3 continuous minutes. There is an initial 8-minute delay prior activation on recirculating units, and an initial 6-minute delay on non-recirculating units. The Freezestat function prevents the unit from starting. The default for this setpoint is 45°F. To change the Freezestat setpoint scroll through the menu tree, locate the Setpoints branch, select Freezestat SP, and enter a new temperature. The allowable temperature range is 35°F - 50°F.

Clogged Filter

An optional clogged filter switch is required for this function. The Clogged Filter function automatically notifies the user of a dirty filter condition. A Clogged Filter indication will appear on the remote panel or local user interface. This function is activated whenever a contact is closed between the appropriate terminals on the unit's terminal strip located in the unit's main control panel. See the Typical Wiring Schematic and Multiplexed Input sections of this manual for more information.

MUA-SVP01A-EN • Direct-Fired Indoor and Outdoor Units 19