Curtain Compensation; Transition Between Lateral & Natural Ventilation - Airstream EXPERT PN110 User Manual

EXPERT PN110

6.4.4. Curtain Compensation

The controller can use the current outside
temperature to adjust the opening and clos-
ing times of the curtains. As the outside
temperature increases, the curtains' Opening
ON Time is increased, causing the curtains
to open faster. As the outside temperature
decreases, the curtains' Closing On Time
is increased, causing the curtains to close
faster. Note that the Curtain Compensation
feature must fi rst be enabled during the instal-
lation. Refer to section 5.1 to set the outside
temperature set point.
Temperature Rises:
When the curtains open, the controller
increases the curtains' On Time by 4% of
the Open Time for every 1°F (0.6°C) in the
compensation interval (i.e. an interval of
3°F means a 12% increase). The curtains'
Off Time is decreased by the same amount.
Compensation
Interval
Outside Current
Set Point Outside
Temperature
Temperature Falls:
When the curtains close, the controller
increases the curtains' On Time by 4% of
the close time for every 1°F (0.6°C) in the
compensation interval (i.e. an interval of
3°F means a 12% increase). The curtains'
Off Time is decreased by the same amount.
Compensation
Interval
Current
Outside
Temperature
6.4.5. Transition between Lateral
& Natural Ventilation
When the natural ventilation mode is on, the air
intake is generally provided exclusively by the
natural ventilation curtain (the fans are stopped
and the lateral air inlet is closed). This section
shows how the controller makes the transition
between the lateral and natural ventilation modes.
Refer to section 4.7.4.9 of this manual to specify
which fan output must stop when entering in
natural ventilation and refer to section 4.5 if you
want the lateral air inlet to close.
• Transition from Lateral to Natural Ventila-
tion (point A on the graph):
When the room temperature reaches the point
at which the curtain starts opening, the con-
troller lets the curtain open until it reaches the
whisker switch. Once the whisker switch is
triggered, the controller knows the air intake
provided by the curtain is suffi cient so it can
now close the lateral inlet and stops the fans.
• Transition from Natural to Lateral Ventila-
tion (point B on the graph):
As the room temperature decreases, the curtain
will close accordingly. When the curtain is suf-
fi ciently closed and has released the whisker
switch, the controller then re-opens the air inlet
T°
and waits until the inlet reaches its respective
position before restarting the fans.
Curtain
status
ON
OFF
Fan output
Outside
T°
ON
Set Point
OFF
The fans restart
when the whisker
switch is released.
• Safety Precautions During The Transition:
A) High Temperature Precautions
If the room temperature increases suddenly
while being in natural ventilation and exceeds
the security limit (Hi T° Restart
Fan Shutoff
in Natural Vent.
The curtain The curtain
closes opens
in timer mode in timer mode
Room T°
Room T°
The curtain
reaches the
Whisker switch:
the fans turn off.
), the con-
(1)
troller immediately re-opens the air inlet,
waits for the inlet to reach its position and
then restarts the fans that were shutoff
In addition, if the controller realises that the
inlet potentiometer is defective, it will make
the inlet open for 60 seconds prior to restart-
ing the fans .
(3)
*(1) Refer to section 4.5 to enable the "Hi T° Restart"
security function. (2) If no lateral inlet is used, the
controller restarts the fans as soon as the room tem-
perature reaches the Hi T° Restart point. (3) This
can only happen when using a potentiometer-based
air inlet. Also note that the air inlet will operate in
security mode after the 60-second delay (refer to
section 6.3.1).
B) Low Temperature Precautions
If the room temperature falls 3°F (1.7°C)
below the lowest curtain's close temperature
and the whisker switch does not detect that
the curtain is closed, the controller immedi-
ately re-opens the air inlet, waits for the inlet
to reach its position and then restarts the
fans that were shutoff . In addition, if the
(1)
controller realises that the inlet potentiometer
is defective, it will make the inlet open for
60 seconds prior to restarting the fans
* (1) If no lateral inlet is used, the controller restarts
the fans as soon as the room temperature falls below
the limit. (2) This can only happen when using a
potentiometer-based air inlet. Also note that the
air inlet will operate in security mode after the
60-second delay (refer to section 6.3.1).
C) Whisker Switch Precautions
If the whisker switch is defective just before
entering in natural ventilation, the controller
will not allow the air inlet to close and will
let the fans run. It will also post a "Defective
whisker switch" message to the alarm log.
Settings:
1. Select:
» START / STOP TEMPS
4. Natural Vent.*
»
* This menu is accessible if the "Hi Restart" option
is enabled in the installation setup (see sec. 4.5).
2. Set the following parameters:
Natural Temp. Zone
Hi T° ReStart 89.0
Hi T° Restart — If the room temperature is
higher or equal to the "Hi T° Restart" value
and we are in natural ventilation, the inlet
will open and the shutoff fans will restart
after the inlets are in position
EXPERT PN110 rev.23
.
(2)
.
(2)
25