VDH ALFANET 20, ALFA 20 User Manual

1

User Manual
ALFA 20 and
ALFANET 20

Thermometer

VDH doc: 070697 Versie: v1.1 Datum: 03-10-2008

Software: ......_ALFA 10/20/30 File: Do070697.wp8 Range: See Sticker

* Function.

The ALFA(NET) 20 is a digital thermostat for panel mounting.
The ALFANET 20 has a RS 485 network connection so it can be read out and
adjusted on the Alfanet.

* Installation.

On the topside of the ALFA(NET) 20 is shown how the sensor, power supply and
network have to be connected.
After connecting the ALFA(NET) 20 to the power supply, a self-test function is
started. As this test is finished, the measured temperature appears in the display.
When the relay is activated, the led 'on' will light-up in the display.

* Control.

The ALFA(NET) 20 Thermostat can be controlled by three
hidden push buttons on the front.
These keys are:

SET - view / change the setpoint.
DOWN - decrease the setpoint.
UP - increase the setpoint.

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* Viewing setpoint.

By pushing the SET key the setpoint appears in the display. The led 'set' starts
blinking. A few seconds after releasing the SET key the setpoint disappears and the
measured temperature is shown in the display.

* Changing setpoint.

Push the SET key and the setpoint appears in the display. Release the at SET key.
Now push 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
shows again in the display.

* Setting internal parameters.

Next to the adjustment of the setpoint, some internal settings are possible like
sensor-offset and network number.
By pushing the DOWN key more than 10 seconds, you 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 keys together with the SET key allows you to change
the value of this parameter.
If after 20 seconds no key is pushed, the ALFA(NET) 20 changes to it's normal
operation mode.

* Parameters ALFA(NET) 20.

Para­meter

Description Parameter Range Standard

Value

04 Offset temperature sensor -15..+15C 0
90

95
96
97
98
99

Network number (Only ALFANET)
Software version
Production year
Production week
Serial number (x1000)
Serial number (units)

1..250

0..255

00..99

1..52

0..255

0..999

1

-

-

-

-

-