1
User manual
ALFA 71 PI SSR 24Vdc
Thermostat
Open collector Solid State Relay output
VDH doc. 100698
Version: v1.0
Date: 06-10-2010
Software: 100801 ALFA71 PI SSR
File: Do100698.wpd
Range: -50/+50,0
C
* Installation.
On the top side of the
ALFA 71 PI SSR 24Vdc
is shown how the sensors, power supply, relays and
Solid-State output has to be connected. After connecting the
ALFA 71 PI SSR 24Vdc
to the power
supply, a self test function is started. As this test is finished the measured temperature appears in the
display.
* Control.
The
ALFA 71 PI SSR 24Vdc
thermostat can be controlled by four pushbuttons on the front.
These keys are:
SET
- view / change the setpoint.
UP
- increase the setpoint.
DOWN
- decrease the setpoint.
C
- hidden push button above the
SET
key and behind
C
symbol.
* Viewing setpoint.
By pushing the
SET
key the setpoint appears in the display. The decimal point of the last display starts
blinking. A few seconds after releasing the
SET
key the setpoint disappears and the measured
temperature is shown again in the display.
* Changing setpoint.
Push the
SET
key and the setpoint appears in the display. Release the
SET
key. Now push the
SET
key again together with the
UP
or
DOWN
keys to change the setpoint. A few seconds after releasing
the keys the measured temperature shows again in the display.
* Status of the Relays.
By pushing the hidden
C
key the display shows the status of the relays. Each display segment shows
the status of the relay output, showing 0=off and 1=on. The code 100 means relay 1 is on and relay
2 is off. A few seconds after releasing the keys the measured temperature shows again in the display.
* PI-percentage.
By pushing the
UP
key the display shows the internal PI-percentage (for P04=2,4) or the status of the
solid state output (for P04=1,3). For the solid state output, 100 means on, 0 means off. A few seconds
after releasing the keys the measured temperature shows again in the display.
* Setting internal parameters.
Next to the adjustment of the setpoint, internal settings can be made like differential, sensor-offset,
setpoint range and the functions of the thermostat.
Push the
DOWN
key more than 10 seconds, to enter the 'Internal Programming Menu'. In the left
display the upper and lower segment are blinking.
Over 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
or
DOWN
key to change the value of this parameter.
If after 20 seconds no key is pushed, the
ALFA 71 PI SSR 24Vdc
changes to the normal operation
mode.
