24
McQuay OM 920-1
Keypad/Display Menu Structure
Economizer Menu
Economizer Pos
is a status only item that is used to indicate percentage that the economizer
dampers/waterside economizer valve is open.
DAT Clg Spt
is an adjustable item used by the controller to set the DAT cooling setpoint. This
value is adjustable only when it is not being set by a reset schedule.
Min OA Pos
is a status only item which indicates the current minimum position of the
outdoor air damper.
Chgover Temp
is an adjustable item which sets the OA dry bulb temperature at which the
units changes over to the economizer operation.
EWT Diff
is an adjustable item that sets a differential below the MAT at which waterside
economizer operation is enabled based on entering water temperature.
Min OA Damper Menu
Min OA Pos
is a status only item which indicates the current minimum position of the
outdoor damper. This value does not go above a value called the Ventilation Limit and does
not go below a value called the Demand Control Ventilation Limit.
Table 13: Economizer Menu
Menu Display Name Item Display Name
Default Setting
Range
Password Level
Economizer
Economizer Pos=
-
0-100%
6
DAT Clg Spt=
55.0°F
40.0-100.0°F
6
Min OA Pos=
-
0-100%
6
Chgover Temp=
55.0°F
0.0-100.0°F
6
EWT Diff=
3.0d°F
0.0-10.0°F
6
Table 14: Min OA Damper Menu
Menu Display Name Item Display Name
Default Setting
Range
Password Level
Min OA Damper
Min OA Pos=
-
0-100%
6
Vent Limit=
20%
0-100%
6
DCV Limit=
10%
0-100%
6
Min OA Reset=
None
None
6
Network
Ext VDC
Ext mA
IAQ VDC
IAQ mA
DesignFlow=
Yes
No
6
Yes
OA @ MinV/mA=
0%
0-100%
6
OA @ MaxV/mA=
100%
0-100%
6
Min V/mA=
0.0/V
0.0-20.0/V/mA
6
Max V/mA=
10.0/V
0.0-20.0/V/mA
6
PPM @DCV Lmt=
800ppm
0-5000ppm
6
PPM @Vnt Lmt=
1000ppm
0-5000ppm
6
PPM=
-
0-5000ppm
6
Min PPM=
0ppm
0-5000ppm
6
Max PPM=
2000ppm
0-5000ppm
6
V/A @Min PPM=
0.0/V
0.0-20.0/V/mA
6
V/A @Max PPM=
10.0/V
0.0-20.0/V/mA
6
Min Fan Diff=
20%
0-100%
6
Max Fan Diff=
50%
0-100%
6
OA Flow=
-
0-60000CFM
6
MinOAFlw Spt=
2000CFM
0-60000CFM
6
Min Clg Spd=
40%
0-100%
6
LoFlo V Lmt=
30%
0-100%
6
