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Standard or Single Speed Fan Operation
FAN TYPE = 1SPEED is not used on RHW units.
2 Speed Fan Operation
The W7220 controller has the capability to work with a sys-
tem 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 11.
Table 11 — 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
527 01 2701 00
FAN SPEED
Low
Low
High
High
Table 12 — 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
Specifications subject to change without notice.
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. See Table 12.
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 cool-
ing will be enabled through Y1 Out or Y2 Out.
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*
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
35
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