3200 Series
20 Part No HA028651 Issue 7.0 Apr-09
4.4.4
Auto, Manual and Off Mode
The controller can be put into Auto, Manual or Off
mode – see next section.
Auto mode
is the normal operation where the output is
adjusted automatically by the controller in response to
changes in the measured temperature.
In Auto mode all the alarms and the special functions
(auto tuning, soft start, timer and programmer) are
operative
Manual mode
means that the controller output power
is manually set by the operator. The input sensor is still
connected and reading the temperature but the control
loop is ‘open’.
In manual mode the MAN beacon will be lit, Band and
deviation alarm are masked, the auto-tuning timer and
programmer functions are disabled.
The power output can be continuously increased or
decreased using the
W
or
V
buttons.
!
Manual mode must be used with care. The
power level must not be set and left at a value that
can damage the process or cause over-heating. The
use of a separate ‘over-temperature’ controller is
recommended.
Off mode
means that the heating and cooling outputs
are turned off. The process alarm and analogue
retransmission outputs will, however, still be active
while Band and deviation alarm will be OFF.
4.4.5
To Select Auto, Manual or Off Mode
Press
and hold
W
and
V
(Mode) together for
more than 1 second.
This can only be accessed from the HOME display.
1.
Auto
’ is shown in the upper display.
After 5 seconds the lower display will
scroll the longer description of this
parameter. ie ’
l oop mode
–
a u to
ma n u a l of f
’
2.
Press
V
to select ‘
mAn
’
.
Press again
to select ‘
OFF
’. This is shown in the
upper display.
3.
When the desired Mode is selected,
do not push any other button. After
2 seconds the controller will return to
the HOME display.
4.
If
OFF
has been selected,
OFF
will be shown in the
lower display and the heating and cooling outputs
will be off
5.
If manual mode has been selected, the
MAN
beacon will light. The upper display shows the
measured temperature and the lower display the
demanded output power.
☺
The transfer from Auto to manual mode is
‘bumpless’. This means the output will remain at
the current value at the point of transfer. Similarly
when transferring from Manual to Auto mode, the
current value will be used. This will then slowly
change to the value demanded automatically by the
controller.
6.
To manually change the power output, press
W
or
V
to lower or raise the output. The output
power is continuously updated when these buttons
are pressed
7.
To return to Auto mode, press
W
and
V
together. Then press
W
to select ‘
Auto
’.
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+
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