Freecooling; Economizer Disable; Economizer Enable; None - Bard MULTI-TEC W18AAPA Service Instructions Manual

Freecooling

If the unit is equipped with an economizer, and
conditions are acceptable for economizer operation,
the MULTI-TEC wall-mount unit will utilize freecooling
operation before the use of any cooling operation
requiring compressor operation to reduce the energy
required to cool the indoor space.

Economizer Disable

There are two methods to disable the economizer if
the use of freecooling is restricted. The first method is
to select None as the economizer type within the Sys.
Config. menu. The second method requires changing
the model number within the Adv. Sys. Config. menu
to reflect a model installed with a blank-off plate (see
model nomenclature in Figure 1 on page 3). Changing
the wall-mount unit model number to reflect a unit with
a blank-off plate will not allow for an economizer type
to be selected therefore defaulting to a disabled state,
along with all sensors/alarms associated with it.

Economizer Enable

The economizer will be enabled for cooling operation
if the model number reflects a wall-mount unit with an
economizer installed, an economizer type other than
None and the conditions for the economizer type are
met. The following list explains the economizer types
and the parameters required for operation:

None

Economizer will not be enabled for freecooling
operation.

Drybulb Only

1. Outdoor air temperature is below the Outdoor Set
outdoor temperature setpoint listed within the Sys.
Config. menu. (Outdoor Set temperature setpoint is
70°F by default.) See Figure 18.
2. LC6000 is not currently in any dehumidification
mode.
3. LC6000 is not currently in any emergency mode.

Temperature and Humidity (Default)

1. Outdoor air temperature is below the Outdoor Set
outdoor temperature setpoint listed within the Sys.
Config. menu. (Outdoor Set temperature setpoint is
70°F by default.) See Figure 18.
2. Outdoor relative humidity is below the OA Humid
Set outdoor humidity setpoint listed within the Sys.
Config. menu. (OA Humid Set humidity setpoint is
80% RH by default.) See Figure 18.
3. LC6000 is not currently in any dehumidification
mode.
4. LC6000 is not currently in any emergency mode.

Enthalpy

1. Outdoor air temperature is below the Outdoor Set,
outdoor temperature setpoint, listed within the Sys.
Config. menu. (Outdoor Set temperature setpoint is
70°F by default.) See Figure 18.
2. Outdoor relative humidity is below the OA Humid
Set outdoor humidity setpoint listed within the Sys.
Config. menu. (OA Humid Set humidity setpoint is
80% RH by default.) See Figure 18.
3. The outdoor air dewpoint is below the OA Dew
Pt Set outdoor dewpoint setpoint, listed within
the Sys. Config. menu. (OA Dew Pt Set dewpoint
setpoint is 55°F by default.) See Figure 19.
4. LC6000 is not currently in any dehumidification
mode.
5. LC6000 is not currently in any emergency mode.
FIGURE 18
Economizer A4 Screen
FIGURE 19
Economizer A5 Screen

Economizer Modulation

The economizer damper output will modulate
between 0% and 100% to maintain a 55°F mixed
air temperature when the outdoor air conditions are
acceptable.
To adjust damper modulation values:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
USER password 2000.
Manual 2100-665D
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