Carrier WeatherMaker 48FC04-07 Installation Instructions Manual page 38

2 Speed Fan Operation
NOTE: 2 Speed Fan operation applies to 48FC**07 models
only.
The W7220 controller has the capability to work with a
system using a 2-speed supply fan. The W7220 does not con-
trol the supply directly but uses the following input status to
determine the speed of the supply fan and controls the OA
damper to the required position, see Table 14.
Table 14 — Fan Speed
STATE
OCC
Y1
Y2
W
DEMAND
OUTSIDE AIR
CONTROLLED
GOOD TO
VENTILATION
ECONOMIZE
(DCV)
NO
NONE
YES
NO
Below CO Set
2
YES
NO
Above CO Set
2
YES
*With stage 3 delay (STG3 DLY) in Advanced setup, COOL Y2-OUT will be turned ON after the delay time specified.
N/A = Not applicable
FAN SPEED
Low
Low
High
High
Table 15 — Economizer Operation - FAN TYPE = 2SPEED
INPUTS
W COOL
(HEAT ON) Y1-IN
ON N/A
OFF OFF
OFF ON
OFF ON
ON N/A
OFF OFF
OFF ON
OFF ON
ON N/A
OFF OFF
OFF ON
OFF ON
ON N/A
OFF OFF
OFF ON
OFF ON
ON N/A
OFF OFF
OFF ON
OFF ON
ON N/A
OFF OFF
OFF ON
OFF ON
The W (heating mode) is not controlled by the W7220 but
it requires the status to know where to position the OA damp-
er for minimum position for the fan speed.
The 2 speed fan delay is available when the system is pro-
grammed for 2 speed fan (in the System Setup menu item).
The 2 speed fan delay is defaulted to 5 minutes and can be
changed in the Advanced Setup menu item. When the unit
has a call for Y1 In and in the free cooling mode and there is
a call for Y2 In, the 2-speed fan delay starts and the OA
damper will modulate 100% open, the supply fan should be
set to high speed by the unit controller.
After the delay one of two actions will happen:
• The Y2 In call will be satisfied with the damper 100%
open and fan on high speed and the call will turn off
OR
• If the call for additional cooling in the space has not been
satisfied then the first stage of mechanical cooling will be
enabled through Y1 Out or Y2 Out.
Refer to Table 16 for economizer operation.
FAN SPEED
COOL COOL COOL
Y2-IN Y1-OUT Y2-OUT
N/A OFF OFF
OFF OFF OFF
OFF ON OFF
ON ON ON
N/A OFF OFF
OFF OFF OFF
OFF OFF OFF
ON ON OFF*
N/A OFF OFF
OFF OFF OFF
OFF ON OFF
ON ON ON
N/A OFF OFF
OFF OFF OFF
OFF OFF OFF
ON ON OFF*
N/A OFF OFF
OFF OFF OFF
OFF ON OFF
ON ON ON
N/A OFF OFF
OFF OFF OFF
OFF OFF OFF*
ON ON OFF*
38
OUTPUTS
DAMPER POSITION
(reference
OCCUPIED
only)
HIGH MIN POS H
LOW MIN POS L
LOW MIN POS L
HIGH MIN POS H
HIGH MIN POS H
LOW MIN POS L
MIN POS L to
LOW
Full Open
MIN POS H to
HIGH
Full Open
HIGH VENTMIN H
LOW VENTMIN L
LOW VENTMIN L
HIGH VENTMIN H
HIGH VENTMIN H
LOW VENTMIN L
VENTMIN L to
LOW
Full Open
VENTMIN H to
HIGH
Full Open
VENTMIN H to
HIGH
VENTMAX H
VENTMIN L to
LOW
VENTMAX L
VENTMIN L to
LOW
VENTMAX L
VENTMAX H to
HIGH
VENTMAX H
VENTMIN H to
HIGH
VENTMAX H
VENTMIN L to
LOW
VENTMAX L
VENTMIN L to
LOW
Full Open
VENTMIN H to
HIGH
Full Open
UNOCCUPIED
Closed
Closed
Closed
Closed
Closed
Closed
Closed to
Full Open
Closed to
Full Open
Closed
Closed
Closed
Closed
Closed
Closed
Closed to
Full Open
Closed to
Full Open
Closed
Closed
Closed
Closed
Closed
Closed
Closed to
Full Open
Closed to
Full Open