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User manual
ALFA 79 ST-PID
Hygrostat.
VDH doc: 080657
Version: v1.1
Date: 13-04-2010
Software: ALFA79-ST-PID
File: Do080657.wpd
Range: 0/+100%RH
* Installation.
On the upper side from the
ALFA 79 ST-PID
is shown how the sensor, supply and
relays should be connected. After power up a self test is started. If the self test is
completed the measured humidity will be shown on the display.
* Control.
The
ALFA 79 ST-PID
hygrostat can be controlled by four push buttons on the
front:
SET
- viewing / changing the adjusted value and reset alarm.
UP
- raise the adjusted value.
DOWN
- lower the adjusted value.
%RH
- hidden key above the
SET
key.
*
Viewing the set points.
By pushing the
SET
key the adjusted set point can be read out. The led ‘set’ also
starts flashing. A few seconds after releasing the
SET
key, the set point
disappears and the measured value will be visible again.
* Changing set point.
Push the
SET
key and the set point appears in the display. Release the
SET
key.
Push the
SET
key again together with the
UP
or
DOWN
keys to change the set
point. A few seconds after releasing the
SET
key the set point disappears and the
measured humidity is shown again.
* Status of the Relays.
By pushing the hidden
%RH
key the display shows the status of the relays. The
three digits are indicating the status from the relays, hereby 0=off and 1=on. The
code 110 means that relay 1 and relay 2 are on and relay 3 is off.
