Carrier 48GC04 Service And Maintenance Instructions page 58

2SP H/C (2 Speed Heat/Cool) Fan Operation
FAN TYPE = 2SP H/C is not used on 48GC units.
3 Speed Fan Operation (single phase units only)
The W7220 controller does not actually control the fan speed
or the heat output of the unit, and only uses this information to
help determine the damper position. On single phase units, the
unit control board (UCB) will reduce the fan speed during
heating when the configured fan speed is set outside the opti-
mized heating speed window. If the job site application forces
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
Table 24 — Economizer Operation - FAN TYPE = 3SPEED
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
this reduction in fan speed during heat, the economizer FAN
TYPE must be set to keep the appropriate outside air intake.
On single phase 48GC 3 to 5 ton units, if reduced the heating
fan speed is lower than the high cooling speed and higher than
the low cooling speed, hence the medium speed name. The
economizer FAN TYPE needs to be set to 3SPEED (3 speed).
This indicates that the heating fan speed is between the Low
cool/vent fan speed and the High cool speed. Refer to Table 24
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*
58
OUTPUTS
DAMPER POSITION
(reference
OCCUPIED
only)
MEDIUM MIN POS M
LOW MIN POS L
LOW MIN POS L
HIGH MIN POS H
MEDIUM MIN POS M
LOW MIN POS L
MIN POS L to
LOW
Full Open
MIN POS H to
HIGH
Full Open
MEDIUM VENTMIN M
LOW VENTMIN L
LOW VENTMIN L
HIGH VENTMIN H
MEDIUM VENTMIN M
LOW VENTMIN L
VENTMIN L to
LOW
Full Open
VENTMIN H to
HIGH
Full Open
VENTMIN M to
MEDIUM
VENTMAX M
VENTMIN L to
LOW
VENTMAX L
VENTMIN L to
LOW
VENTMAX L
VENTMIN H to
HIGH
VENTMAX H
VENTMIN M to
MEDIUM
VENTMAX M
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