Carrier CRECOMZR103A00 - Multi-Speed Fan Support

17
MULTI-SPEED FAN SUPPORT
The economizer controller supports connection to 2 and 3-speed
fans. When the unit is equipped with a multi-speed fan, the damp
-
er responds to multiple fan speeds via multiple minimum positions
(MIN POS) to keep minimum airflow. Refer to Tables
13-15.
If DCV (demand controlled ventilation) is enabled, then each fan
speed corresponds to two damper position ventilation setpoints
(VENT MIN, VENT MAX), e.g., Pos L corresponds to
2VENTMIN L... 2VENTMAX L. Refer to Table
16.
If CO
2
sensor is connected but DCV is disabled, then each fan
speed corresponds to one minimum damper position ventilation
setpoint. Refer to Table
17.
Table 11 — 1 and 2-Stage Cooling Stage I/O Logic
ECONOMIZER
CONDITION MET
Y1 Y2
COOLING
STAGE 1
COOLING
STAGE 2
NO On On On On
NO On Off On Off
NO Off Off Off Off
YES On On On On/Off
a
NOTE(S):
a. If OAT  MAT setpoint (3MAT SET), then Relay 2 is always OFF to disable
Cooling Stage 2. Otherwise, if both stages of cooling (Y1 and Y2) are ON for
more than a set time (15 minutes by default), Y2 remains ON, and the OAT is
higher than MAT setpoint, then Relay 2 energizes to allow Y2 pass-through to
enable Cooling Stage 2. To change the set time, configure 3STG3 DLY as de-
sired. See Advanced Settings page 27 for more details of 3STG3 DLY.
YES On Off Off Off
YES Off Off Off Off
Table 12 — 2 and 3-Stage Cooling Stage I/O Logic
ECONOMIZER
CONDITION
MET
Y1 Y2 Y3
COOLING
STAGE 1
COOLING
STAGE 2
COOLING
STAGE 3
NO On On On On On On
NO On On Off On On Off
NO On Off Off On Off Off
NO Off Off Off Off Off Off
YES On On On On On On/Off
a
NOTE(S):
a. If OAT  MAT setpoint, then Relay 3 is always OFF to disable Cooling Stage 3.
Otherwise, if all cooling stages (Y1, Y2 and Y3) are ON for more than a set time
(15 minutes by default), Y3 remains ON, and the OAT is higher than MAT set-
point, then Relay 3 energizes to allow AUX1/AUX2 pass-through to enable
Cooling Stage 3. To change the set time, configure 3STG3 DLY as desired. See
Advanced Settings page 27 for more details of 3STG3 DLY.
YES On On Off On On/Off Off
YES On Off Off Off Off Off
YES Off Off Off Off Off Off
IMPORTANT: The economizer controller can tolerate thermo-
stat wiring mismatch, e.g. Thermostat Y1  Economizer Y2-In,
Thermostat Y2  Economizer Y1-In. The handling logic is
Stage =Y1I + Y2I + Y3I. For example, Y1O =1 if Stage > =1,
Y2O =1 if Stage > = 2, Y3O=1 if Stage=3.
Table 13 — Damper MIN POS for 2-Speed Fan
a
NOTE(S):
a. A multi-speed fan is not controlled by the economizer controller, but an external
logic board.
Y1 Y2 W1 or O/B Spd L Spd H Pos L Pos H
X —— X—X—
X X— —X—X
— —X —X—X
LEGEND
Pos L — Damper MIN POS for Low-Speed Fan
Pos H — Damper MIN POS for High-Speed Fan
Spd L — Low Speed (Fan)
Spd H — High Speed (Fan)
Table 14 — Different Fan Speeds with Different
Configured Outputs
a
NOTE(S):
a. If a single-speed fan connects to the Controller, then it opens directly on the call
of cooling/heating. The damper position is Pos H.
FAN
TYPE
1-SPEED
COOLING
b
b. Configured by Y1O, Y2O, or Y3O.
2-STAGE
COOLING
b
3-STAGE
COOLING
b
1-SPEED
FAN
c
c. Configured by 6FAN.
• Spd H)
(regardless of
cooling
demand,
OCC=Yes)
• Spd H)
(regardless of
cooling
demand,
OCC=Yes)
• Spd H
(regardless of
cooling demand,
OCC=Yes)
2-SPEED
FAN
c
• Spd L 
(0 or 1 cooling
demand)
• Spd H 
(2 cooling
demands)
• Spd L
(0 or 1 cooling
demand)
• Spd H3) 
(2 cooling
demands)
• Spd L 
(0 or 1 cooling
demand)
• Spd H 
(2 or 3 cooling
demands)
LEGEND
Spd L — Low Speed (Fan)
Spd H — High Speed (Fan)
Table 15 — Different Damper Minimum Positions with
Different Configured Outputs
FAN
TYPE
1-SPEED
COOLING
a
NOTE(S):
a. Configured by Y1O, Y2O, or Y3O.
2-STAGE
COOLING
b
3-STAGE
COOLING
b
1-SPEED
FAN
b
b. Configured by 6FAN.
•Pos H
(regardless of
cooling
demand,
OCC=Yes)
•Pos H
(regardless of
cooling
demand,
OCC=Yes)
•Pos H
(regardless of
cooling
demand,
OCC=Yes)
2-SPEED
FAN
b
•Pos H
(regardless of
cooling
demand,
OCC=Yes)
• Pos L 
(0 or 1 cooling
demand)
•Pos H
(2 cooling
demands)
• Pos L4
(0 or 1 cooling
demand)
• Pos H 
(2 or 3 cooling
demands)
LEGEND
Pos L — Damper MIN POS for Low-Speed Fan
Pos H — Damper MIN POS for High-Speed Fan