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EXPERT LA
6.3.3
Curtain Compensation
The controller can slightly adjust opening of the
curtains as a function of outside temperature: as
the outside temperature increases, the controller
increases the opening time of the curtains. As a
result, curtains open faster when the outside tem-
perature gets warm. Likewise, when the outside
temperature gets cold the controller increases the
closing time of the curtains. This compensation is
optional. To use it, enable the curtain compensa-
tion in the Installation Setup (section 4.5). Then,
set the outside temperature set point (section 5.1).
When temperature rises:
When the curtain opens, the controller increases
the curtain's On Time by 4% for every 1°F (0.6°C)
in the compensation interval (i.e. an interval of 3°F
means a 12% increase). The curtain's Off Time is
decreased by the same amount.
Compensation interval
Outside T°
set point
When temperature falls:
When the curtain closes, the controller increases
the curtain's On Time by 4% for every 1°F (0.6°C)
in the compensation interval (i.e. an interval of 3°F
means a 12% increase). The curtain's Off Time is
decreased by the same amount.
Compensation interval
Current
outside T°
46
EXPERT LA rev.00
Temp.
Current
outside T°
Temp.
Outside T°
set point
6.3.4
Stopping Fans in Natural Vent.
Whisker switches are used to stop some on/off and
variable-speed fan outputs when the controller is in
natural ventilation. These switches tell when the
curtains are sufficiently opened.
When temperature rises (point A on the graphic):
The controller gradually opens the curtain as tem-
perature rises. It can also disable a chosen selec-
tion of fans when the curtain is sufficiently opened
(when the curtain has reached its whisker switch).
When temperature falls (point B on the graphic):
At point B, the curtain is already opened and the
fans are stopped. The controller gradually closes
the curtain as temperature falls. The controller re-
starts the fans when the curtain closes and releases
its whisker switch.
Fan Shutoff
in Natural Vent.
CURTAIN
STATUS
The curtain
closes according
to a timer
ON
OFF
FAN
OUTPUT
A
ON
OFF
The fans restart
when the Whisker
switch is released
Security: If the temperature drops suddenly or if
the whisker switch is defective, the controller au-
tomatically restarts the fans when the tempera-
ture falls 5°F (3°C) below the lowest curtain's clos-
ing temperature. When this situation occurs, a de-
fective whisker switch alarm is posted to the alarm
log.
Refer to section 4.8 to select what fan
relays must turn off in natural ventilation.
The curtain
opens according
to a timer
Room T°
B
Room T°
The curtain has reached
the Whisker switch:
the fans turn off.
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