Carrier 50FCQ 04-07 Series Service And Maintenance Instructions page 56

Table 26 — Enthalpy Operation with DCV (CO
DEMAND OUTSIDE AIR
CONTROLLED GOOD TO
VENTILATION (DCV) ECONOMIZE
Below CO Set
2
Above CO Set
2
NOTE(S):
a. With 2SP FAN DELAY (Advanced Setup Menu) when in the economizing mode there is a delay for the high speed fan to try to satisfy the call for second stage cooling
by turning on the fan to high and opening the OA damper 100% before the first stage mechanical cooling is enabled.
b. With stage 3 delay (STG3 DLY) in Advanced setup menu can turn on second stage of mechanical cooling Y2-O after the delay if the call for Y1-I and Y2-I have not been
satisfied.
ENTHALPY SETTINGS
When the OA temperature, enthalpy and dew point are below the
respective set points, the Outdoor Air can be used for economiz-
ing. Figure 75 shows the new single enthalpy boundaries in the
W7220. There are 5 boundaries (set points ES1 through ES5),
which are defined by dry bulb temperature, enthalpy and dew
point.
Refer to Table 27 for ENTH CURVE set point values.
Y1-I Y2-I
OFF OFF
No ON OFF
ON ON
OFF OFF
ON OFF
Yes
ON ON
OFF OFF
No ON OFF
ON ON
OFF OFF
Yes ON OFF
ON ON
Sensor) — Two-Speed Fan
2
FAN
Y1-O Y2-O
SPEED
LOW 0-v/Off 0-v/Off
LOW 24-v/On 0-v/Off
HIGH 24-v/On 24-v/On
LOW 0-v/Off 0-v/Off
LOW 0-v/Off 0-v/Off
HIGH 24-v/On 0-v/Off
LOW 0-v/Off 0-v/Off
LOW 24-v/On 0-v/Off
HIGH 24-v/On 24-v/On
LOW 0-v/Off 0-v/Off
LOW 0-v/Off 0-v/Off
DELAY
a
HIGH 0-v/Off
24-v/On
56
OCCUPIED
VENTMIN
VENTMIN
VENTMIN
VENTMIN
VENTMIN to
Closed to Full-Open
Full-Open
VENTMIN to
Closed to Full-Open
Full-Open
VENTMIN to
VENTMAX
VENTMIN to
VENTMAX
VENTMIN to
VENTMAX
VENTMIN to
VENTMAX
VENTMIN to
Closed to Full-Open
Full-Open
VENTMIN to
b Closed to Full-Open
Full-Open
UNOCCUPIED
Closed
Closed
Closed
Closed
Closed
Closed
Closed
Closed