2
* Viewing setpoints.
Viewing setpoint of maximum alarm:
By pushing the
SET
key first and then the
UP
key together the maximum alarm setpoint
appears in the display. The led 'set high' starts blinking.
Viewing setpoint of minimum alarm:
By pushing the
SET
key first and then the
DOWN
key together the maximum alarm
setpoint appears in the display. The led 'set low' starts blinking.
A few seconds after releasing the keys the setpoint disappears and the measured
temperature is shown in the display.
* Changing setpoints.
Push the
SET
key together with the
UP
or
DOWN
key and the maximum alarm setpoint or
minimum alarm setpoint appears in the display. Release both keys.
Now push and hold the
SET
key again and together with the
UP
or
DOWN
keys the setpoint
can be changed. A few seconds after releasing the keys the measured temperature is shown
again in the display.
* Action of the alarm functions.
The
ALFA(NET) 23
alarm thermostat has a minimum alarm and a maximum alarm, both with
there own setpoint. We can choose off two different kind of alarms (PARAMETER 27)
namely:
a watchdog alarm (relay normally activated, at alarm, it falls off and the led 'alarm' burns.
On power failure the alarm relay also falls off.)
or a regulated alarm (relay normally not activated, at alarm, it will be activated and the led
'alarm' burns.
With PARAMETER 28 we can choose for a auto reset alarm or a hold alarm after
temperature recovering. Also it is possible to give both setpoints there own offset and
differential, see function diagram.
Each alarm can be set at an alarm-delay time (PARAMETER 23 and 24), when the
temperature passes the set alarm point, the led 'alarm' first starts to blink. If the temperature
will recover within the delay time, no alarm occurs. If an alarm will continue after the delay
time, the led 'alarm' burns continuously, and the display alternates between the temperature
and 'H' for high-alarm (max.) or 'L' for low-alarm (min.) to indicate the alarm.
To reset an alarm press the
SET
key.
* Setting internal parameters.
Next to the adjustment of the setpoint, some other internal settings are possible, like
differential, sensor-offset, setpoint range.
By pushing the
DOWN
key more than 10 seconds, you enter the 'internal programming
menu'. In the left display the upper and lower segments are blinking. With the
UP
and
DOWN
keys the required parameter can be selected (see table for the parameters). If the required
parameter is selected, the value can be read-out by pushing the
SET
key. Pushing the
UP
and
DOWN
keys, allows you to change the value of this parameter. If after 20 seconds no
key is pushed, the
ALFA(NET) 23
changes to it's normal operation mode.
* Parameter ALFA(NET) 23.
Para-
meter
Description Parameter
Range
Standard
Value
02
03
04
Minimum setpoint
Maximum setpoint
Offset temperature sensor
-50/+150
C
-50/+150
C
-15/+15
C
-50
+150
0
10
11
Startup delay after power failure
Relay on at sensor failure
0..99 Minutes
0 = No, 1 = Yes
0
0
