VDH ALFA 71 KVA User Manual

User manual
ALFA 71 KVA 12Vdc
Thermostat
VDH doc. 180934
Software: ALFA71 KVA
* Installation.
On the top side of the ALFA 71 KVA is shown how the sensors, power supply and relays are to be
connected.
After connecting the ALFA 71 KVA to the power supply, a self test function is started. As this test is
finished the measured temperature appears in the display. Normally this is the temperature of sensor-1,
unless sensor-2 is active as control sensor (P05=1) in that case the average temperature of both
sensors is displayed and used for control.
* Control.
The ALFA 71 KVA 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.
* Viewing the individual sensors.
By pressing the UP and DOWN key together, the individual sensors can be show in the display. After
releasing the keys, the measured temperature of sensor-1 can be shown by pushing the UP key or the
measured temperature of sensor-2 can be shown by pushing the DOWN key.
A few seconds after releasing the keys the (average) 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 110 means relay 1 and 2 are on and relay 3 is off.
Version: v1.0
File: Do180934.wpd
1
Datum: 09-10-2018
Range: -30/+110,0°C