Carel ir33 Universale series User Manual page 24

ENG
5.2.2 Reverse (parameter c0=2)
"Reverse" operation is similar to "direct" operation, however the outputs
are activated when the value being controlled decreases, starting from
the set point (St1). When the value measured is less than or equal to
St1-P1 (in proportional only operation), all the outputs are activated.
Similarly, if the value measured starts rising, the outputs are deactivated
in sequence. When reaching St1, all the outputs are deactivated.
Mod. V
OUT1
ON
OFF
P1 B1
St1
OUT4 OUT3
Key
St1 Set point 1
P1 Set point diff erential 1
OUT1/2/3/4 Output 1/2/3/4
B1 Probe 1
This is the default setting.
5.2.3 Dead zone (parameter c0=3)
The aim of this control mode is to bring the measured value within an
interval around the set point (St1), called the dead zone. The extent of the
dead zone depends on the value of parameter P3. Inside the dead zone, the
controller does not activate any outputs, while outside it works in "direct"
mode when the temperature is increasing and in "reverse" mode when it
is decreasing. According to the model used, there may be one or more
outputs in "direct" and "reverse" modes. These are activated or deactivated
one at a time, as already described for modes 1 & 2, according to the value
measured and the settings of St1, P1 and P2.
Mod. V
OUT1
ON
OFF
P1 P3 B1
St1
Mod. Z
OUT2 OUT1
P1
Key
St1
P1/P2
P3
OUT1/2/3/4
B1
When the controller only has 1 output, it works in "reverse" mode with
dead zone.
ir33 universale +030220801 - rel. 1.0 - 16.04.2008
Mod. W
OUT2 OUT1
P1
St1
Mod. Z
OUT2 OUT1
ON
OFF
B1
P1
St1
Mod. W
OUT1 OUT2
P1 P3 P3 P2
St1
OUT3 OUT4
P3 P3 P2
St1
Set point 1
"Reverse"/"direct" diff erential
Dead zone diff erential
Output 1/2/3/4
Probe 1
5.2.4 PWM (parameter c0=4)
The control logic in PWM mode uses the dead zone, with the outputs
activated based on pulse width modulation (PWM). The output is
activated in a period equal to the value of parameter c12 for a variable
time, calculated as a percentage; the ON time is proportional to the value
measured by B1 inside the diff erential. For small deviations, the output will
be activated for a short time. When exceeding the diff erential, the output
will be always on (100% ON). PWM operation thus allows "proportional"
control of actuators with typically ON/OFF operation (e.g. electric heaters),
so as to improve temperature control. PWM operation can also be used to
gave a modulating 0 to 10 Vdc or 4 to 20 mA control signal on IR33 (DN33)
Universal models A, D with outputs for controlling solid state relays (SSR).
ON
In this case, the accessory code CONV0/10A0 needs to be connected to
convert the signal. In PWM operation, the "direct"/"reverse" icon fl ashes.
OFF
B1
Mod. V
OUT1
P1 P3
St1
OUT2
P1/2
Key
St1
P1/P2
P3
OUT1/2/3/4
B1
When the controller only has 1 output, it works in "reverse" mode with
dead zone.
PWM mode should not be used with compressors or other actuators
whose reliability may be aff ected by starting/stopping too frequently.
For relay outputs, parameter c12 should not be set too low, so as to not
compromise the life of the component..
5.2.5 Alarm (parameter c0=5)
In mode 5, one or more outputs are activated to signal a probe
disconnected or short-circuited alarm or a high or low temperature alarm.
Models V and W only have one alarm relay, while model Z has two: relay
B1
3 is activated for general alarms and for the low temperature alarm, relays
4 is activated for general alarms and for the high temperature alarm. The
activation of the alarm relay is cumulative to the other signals in the other
operating modes, that is, alarm code on the display and audible signal.
For models W & Z, the relays not used to signal the alarms are used for
control, as for mode 3 and shown the following diagrams. This operation
mode is not suitable for the models B and E.
Par. Description
P25 Low temperature alarm threshold
B1
P29=0, P25=0: threshold disabled;
P29=1, P25= -50: thresh. disabled
P26 High temperature alarm threshold
P29=0, P26=0: threshold disabled;
P29=1, P26= 150: thresh. disabled
P27 Alarm diff erential
P28 Alarm delay time
P29 Type of alarm threshold
0=relative;
1=absolute.
24
Mod. W
100%
100%
OUT1
0%
0%
B1 P1 P3 P3
St1
Mod. Z
100%
OUT1 OUT3
0%
P1/2 P3 P3 P2/2
St1
Set point 1
"Reverse"/"direct" diff erential
Dead zone diff erential
Output 1/2/3/4
Probe 1
Def Min
-50 -50
150 P25
2 0
120 0
1 0
OUT2
P2 B1
OUT4
P2/2 B1
Max UoM
P26 °C/°F
150 °C/°F
50 °C/°F
250 min
1 -