1
User manual
ALFA 75 RTDF
Cool/Defr. Thermostat
with fan-control and
realtime defrost.
VDH do c.020993
Version: v 1.1
Date: 15-02-2005
Software: ALFA(NET) 75 RTDF
File: Do020993.WP8
Range: -50,0/+50,0
/
C
* Description.
The
ALFA 75 RTDF
is a co ol/def rost 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 ish ed the m ea su red te m pe rature of the te m perature-se ns or (con trol) ap pe ars in the display.
* Control.
The
ALFA 75
thermostat can be controlled by four push buttons on the front. These keys are:
SET
- view / cha nge the s etpo int.
UP
- increase value.
D OW N
- decrease value.
/
C
- hidden push button above
SET
key and behind
/
C
sym bo l.
* 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.
Summary of Contents for ALFA 75 RTDF
Page 6: ...6 Dimensions...
Page 7: ...7 Connections...
