VDH ALFA 19, User Manual, Page: 1 / 4

1
User manual
ALFA 19 and
ALFANET 19
Hygrostat.
VDH doc: 071729 Version: v1.1 Date: 06-12-2007
Software: 061196_ALFA 19/29/39 File: Do071729.wpd Range: 0/100%RH per 1%RH
* Function.
The ALFA(NET) 19 is a digital hygrostat for rail mounting. The function from the hygrostat can be
programmed for humidify or dehumidify.
The
ALFA NET 19 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) 19 is shown how the sensor, power supply and relay have to be
connected.
After connecting the
ALFA(NET) 19 to the power supply, a self-test function is started. As this test is
finished the measured humidity appears in the display.
When the relay is activated, the led 'on' will light-up in the display.
* Control.
The ALFA(NET) 19 hygrostat can be controlled by three push buttons on the front.
These keys are:
SET - view / change the set point.
UP - increase the set point.
DOWN - decrease the set point.
* 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 set point disappears and the measured humidity is shown in the display.
* Changing setpoint.
Push the SET key and the set point appears in the display. Release the at SET key. Now push the SET
key again and together with the UP or DOWN keys the set point can be changed. A few seconds after
releasing the keys the measured humidity shows again in the display.