2
*Setting internal parameters.
Next to the adjustment of the set point, some internal settings can be made like
differentials, sensor-adjustments, set point-range and alarm-settings.
By pushing the DOWN key for more than 10 seconds, you enter the 'internal
programming menu'. On the left display the upper and the lower segments are
flashing. 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 and DOWN keys allows you
to change the value of this parameter.
If no key is pushed for 20 seconds, the ALFA 79 ST-PID changes to it’s normal
operation mode.
*Sensor adjustments.
The sensor can be adjusted by using the offset sensor (parameter 05).
Indicates a sensor e.g. 2%RH too much, the according Sensor-offset parameter has
to be decreased with 2%RH.
*Error codes.
On the display from the ALFA 79 ST-PID can appear the following error codes:
E1 -RH sensor defect. Solution E1:
-Check if the sensor is connected well.
-Check RH-signal (0/+100%RH = 0/+10Vdc)
-Replace the sensor.
EE -Adjustments are lost. Solution EE:
-Reprogram the adjustments.
*Technical details.
Type : ALFA 79 ST-PID Hygrostat.
Range : 0/+100%RH read out per 1%RH
Read out : 3-digit 7-segments display
Status LED’s : LED 'SET' en LED 'RH'
Supply : 12 Vac 50/60Hz (-5/+10%).
Solid-state : Ry1 solid state output 12Vdc (pulse modulating)
Relays : Ry2 spdt (C/NO/NC) 250V/8A(cos=1) or 250V/5A(cos=0.4)
Control : Through push buttons on the front.
Front : Polycarbonate.
Input voltage : 0/+10Vdc (0/+100%RH) (Ri = 10KOhm)
Input contact : C/NO contact(= 100% output) (Potential free input contact)
Dimensions : 35 x 77 x 71,5mm (hwd).
Panel cut out : 29 x 71mm (hw).
Accuracy : ± 0,5% from the range.
- Provided with memory protection during power failure.
- Equipped with self-test function and sensor-failure detection.
- Connection with screw-terminals.
- Special version on request available.
