VDH ALFA 75 RTDF User Manual

User manual
ALFA 75 RTDF
Cool/Defr. Thermostat
with fan-control and
realtime defrost.
VDH do c.020993
Software: ALFA(NET) 75 RTDF
* Description.
The ALFA 75 RTDF is a co ol/defrost therm osta t with various defrost- a nd fa n-contro l settings .
* Installation.
On the top side of the ALFA 75 RTDF is shown how the sensor, power supply and relays has to be
con nec ted.
After connecting the ALFA 75 RTDF to the power supply, a self test function is started. As this test
is fin ished the m easured tem perature of the tem perature-sensor (control) ap pears in the display.
* Control.
The ALFA 75 thermostat can be controlled by four push buttons on the front. These keys are:
SET - view / change the setpo int.
UP - increase value.
D OW N - decrease value.
C - hidden push button above SET key and behind C sym bol.
* View setpoint.
By pushing the SET key the setpoint appears in the display. The decimal point of the last display
starts blinking to indicate this. After a few seconds after releasing the SET key the setpoint
disappears and the measured temperature is shown again.
* 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 D OW N keys to change the setpoint. After a few seconds
after releasing the SET key the setpoint disappears and the measured temperature is shown again.
* 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(com pr.) en relay 2(fan) are on and relay 3(defr.) is off.
Version: v 1.1
File: Do020993.WP8
1
Date: 15-02-2005
Range: -50,0/+50,0 C