Trane Direct-Fired Indoor and Outdoor Make-Up Air Units Wheelchair User Manual


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