10
INTER 2V4SA, rev.02
INTER 2V4SA
5.
Changing a Parameter
5.1. Using the Display
Flashing Values:
The display
will flash in certain cases
and not in others. The flash-
ing indicates that the value
shown can be adjusted. A
value that is not flashing
cannot be adjusted.
Relative and Absolute Values:
Some param-
eter adjustments are displayed both as a
relative value and an absolute temperature.
This applies all heating and cooling differ-
entials, the mist differential and the heater
offset. The parameter is first displayed as a
relative value. The corresponding absolute
temperature is displayed after six seconds if
no action is taken by the user. The absolute
value is the temperature at which the stage
turns on (except in the case of the heater and
mist offsets where the value displayed is the
temperature at which the stage turns off). If
the user presses a button, the relative value
reappears. For example, when the user se-
lects a differential menu, i.e. STAGES 3-6DIF-
FERENTIAL, the sequence is as follows:
(i) The current differential for stage 3 flashes
on the display, alternating with "
3 dIF
".
3dIF
2 .0
(ii) If, after about 6 seconds, no action is
taken by the user, the absolute temperature
value is displayed, alternating with "
St 3 On
".
In this case, the absolute value is: Set Point
+ Bandwidth 1 + Offset 2 + Bandwidth 2
+ Differential 3.
78.0
ST3 on
2 .0
(iii) When the user presses on an adjustment
button to make an adjustment to differential,
the relative value reappears on the display.
2 .3
5.2. Locking the Parameter
Settings
The parameter settings can be locked to pre-
vent accidentally modifying them. When the
settings are locked, only the temperature set
point and the Stage 1 minimum ventilation
speed can be modified (as long as the tem-
perature ramp and the minimum ventilation
speed ramp are deactivated respectively).
• Set internal switch # 1 to
ON
to lock the parameters. The
"Locked Parameter"
status LED
turns on.
• Set internal switch # 1 to
OFF
to unlock the parameters. The
"Locked Parameter"
status LED
turns off.
ON
OFF
1
1
ON
OFF
31
INTER 2V4SA, rev.02
INTER 2V4SA
11.
Alarms
The controller sets off an alarm in the case
of a power failure, a fault in the supply circuit
or a high or low temperature.
11.1. Temperature Alarms
The diagram below explains how temperature
alarms are detected. When the average room
temperature exceeds the high temperature
alarm setting (Set Point + Hi Offset), a high
temperature alarm sets off. When the aver-
age room temperature decreases below the
low temperature alarm limit (Set Point - Lo
Offset), a low temperature alarm sets off.
The
critical temperature
is the absolute maxi-
mum allowable temperature in the room.
Temperature
Alarms
Alarm
Room T°
Time
Set
Point
Normal temperature range (no alarm)
Alarm : temperature out of range
Hi Offset
Lo Offset
11.2. Outside Temp. Com-
pensation on Temp.
Alarms
In situations where the outdoor temperature
is high, the room temperature will rise as
warm air enters the building through ven-
tilation inlets. If the high set point is not
adjusted to take this into account, a high
temperature alarm may be needlessly set
off. To avoid this situation, the system can
compensate for high outdoor temperatures
when monitoring temperature alarms. When
this feature is activated and the outdoor
temperature is close to the high set point,
the room temperature is monitored with re-
spect to the outdoor temperature. An alarm
sets off only if the room temperature rises
above the outdoor temperature by a certain
value called the offset. In addition to this, the
system also uses a critical high temperature
as an absolute limit on room temperature.
When room temperature reaches the critical
high temperature, an alarm is set off. This
compensation feature is automatically en-
abled when an outside temperature probe is
connected to the controller.
Outside T° Offset:
In general, the room tem-
perature is greater than the outdoor tempera-
ture by a certain number of degrees, called
the offset. The offset determines when an
alarm sets off. It is the number of degrees the
room temperature can rise above the outdoor
temperature without setting off an alarm.
