Microprocessor Controller for DOAS
22
®
Menu
R
EFRIGERATION
M
ENU
Consult factory prior to adjusting parameters in Refrigeration Menu.
T
HIS
SCREEN
ALLOWS
A
DJUSTMENT
FOR
D
ELAY
T
IME
B
ETWEEN
D
AMPER
O
PENING
AND
F
AN
O
PERATION
.
This timer allows the damper to open before the fan start sequence begins.
This prevents the fans from having to overcome higher static pressure when the
damper(s) are opening.
T
HIS
SCREEN
DISPLAYS
THE
O
UTDOOR
A
IR
D
AMPER
S
ET
P
OINT
AND
ONLY
APPEARS
IF
UNIT
IS
EQUIPPED
WITH
A
MODULATING
OUTDOOR
AIR
AND
RECIRCULATING
DAMPER
.
The set point is the proportional percentage of the outdoor air damper being
open.
0% = Full recirculation air
100% = Full outdoor air
Minimum Position
– When in the occupied mode, the active set point will be
equal to a local minimum OA set point, which may be constant or reset by fan
speed if equipped with a modulating supply fan. The OA damper set point can
then be further adjusted between the minimum and maximum OA settings with
sequences such as DCV CO
2
, Building Pressure and Economizer.
Maximum Position
– Each sequence that can adjust the OA damper set point
contains a maximum position to prevent excess OA. The active set point will be
determined based on the greatest demand of the configured sequences. For
example, if a unit is equipped with a DCV CO
2
and an economizer sequence, the
OA damper set point will react to an economizer demand even if the CO
2
set point
is satisfied. Likewise, if economizer is not available but CO
2
is above set point, the
OA damper will open to satisfy the CO
2
set point.
Economizer
– The active set point will be reset based on Economizer demand,
between the minimum and maximum positions.
Possible Setpoint Sources:
Local
– The minimum outdoor air percentage is constant; set by the controller.
SF Reset
– The min and max positions are reset by the supply fan speed.
BMS
– The BMS can directly control the OA damper position up to the max BMS
percentage.
Building Pressure
– Damper position is reset by a building pressure control loop.
DCV CO
2
– Damper position is reset by a demand-controlled ventilation control
loop based on room CO
2
levels.
2 Position
– Damper position is reset to “2-Pos/Max Econ:” set point when a
contact closure is made. The 2-position damper operation can also be setup to
bring the unit into temporary occupied mode until the contact is broken (Max
Ventilation Mode - enabled in manufacturer menu settings).
Control Variables
Refrigeration
The
Refrigeration
menu allows the user to view and adjust compressor and
condenser settings, if equipped.
Control Variables
Damper Control
The
Damper Control
menu’s allows the user to adjust damper control setpoints.
Economizer setpoint adjust will also be found at this location if the unit is
equipped with outside air and recirculation dampers.
