VDH ALFA 52-VS User Manual

1

User manual
ALFA 52 VS 0-20OC
Differential Thermostat.

VDH doc. 080331 Versie: v1.2 Datum: 22-04-2010

Software; File: Do080331.wpd Static range (see sticker);
992903 ALFA 52/72 VS 20 -50..+50 Typenr.: 904.000806 -50/+50,0C
100320 ALFA 52/72 VS 20 -20..+80 Typenr.: 904.000929 -20/+80,0C
992901 ALFA 52/72 VS 20 0..+100 Typenr.: 904.000916 0/+100,0C

* Installation.

On the connection diagram of the ALFA 52-VS is shown how the sensors, power supply and relays
has to be connected. After connecting the ALFA 52-VS to the power supply, a self test function is
started. As this test is finished, the measured differential temperature of sensor-1 minus sensor-2
appears in the display.

* Control.

The ALFA 52-VS thermostat can be controlled by four pushbuttons on the front These keys are:

SET - view / change set point and reset the alarm

 (UP) - increase the set point.
 (DOWN) - decrease the set point.

MODE - relays status key.

* Viewing the temperature from sensor-1 and sensor-2.

By pressing the UP and DOWN keys simultaneously and after that the UP key, the measured value
from sensor-1 can be read-out. If the down key is pressed, the measured value from sensor-2 is
shown. If no key is pressed for a few seconds, the differential temperature is shown again.

* Viewing the delta-setpoint.

By pushing the SET key, the set point of delta thermostat appears in the display.
A few seconds after releasing the keys the setpoint disappears and the differential temperature is
shown again in the display.

* Changing the delta-setpoint.

Push the SET key. The delta-setpoint appears in the display. Release the SET key. Now push the SET
key again together with the UP or DOWN keys to change the set point. A few seconds after releasing
the keys, the measured differential temperature is shown again in the display.

* Status of the Relays.

By pushing the MODE key the display shows the status of the relays.
Each digit shows the status of one relay output, showing 0 = off and 1 = on.
The code 110 means relay 1 and 2 are on and relay 3 is off.
Relays 1 and 2 are used for the differential thermostat (see function diagram).
Relay 3 is used as an alarm relay.

2

* Adjustment sensors.

Sensor-1 can be adjusted by using the Sensor Offset parameter 05 and Sensor-2 can be adjusted by
using the Sensor Offset parameter 06. Indicates a Sensor e.g. 2 C to much, the according Sensor
Offset has to be decreased with 2C.

* Error messages.

On the display of the ALFA 52-VS the following error messages can appear:

E1 - Sensor-1 failure. Solution E1, E2:
E2 - Sensor-2 failure. - Check if sensor is connected correctly.

- Check sensor (1000 at 25OC)

- Replace sensor

EEE - Settings are lost. Solution EEE:

- Reprogram the settings.

Reset Alarm. When an error-messages appears it can be reset by pushing the SET key.

The function of this key depends on parameter P42.

After reset alarm the differential temperature appears again in the display or the error-code E..
alternates with extra indications as the temperature is out of measure range. These indications are;

‘L’ indicates a short-circuit sensor.

‘H’ indicates a open-circuit sensor.
Whereby the first segment is used to indicate these codes for Sensor-1 the second segment shows
‘-‘ and the last segment indicates the codes for Sensor-2.
F.i.; L - - Indicates a short circuit of Sensor-1 and Sensor-2 okay

- - H Indicates a open-circuit of Sensor-2 and Sensor-1 okay
H - L Indicates Sensor-1 with a open-circuit and Sensor-2 with a short-circuit

* Technical data ALFA 52-VS.

Type : ALFA 52-VS Differential thermostat (Rail)
Range : Differential temperature in display 0/+20OC (0,1)
Static range sens. : -50/+50,0C, above -10C read-out in 0,1C or

-20/+80,0C, above -10C read-out in 0,1C or

0/+100,0C, read-out in 0,1C
Supply : 230Vac 50/60Hz (-5/+10%) or else see product sticker
Read-out : 3-digit 7-segments display
Relays : Ry1= SPST(NO) 250V/8A (cos =1) or 250V/5A (cos =0.4)

Ry2= SPST(NO) 250V/8A (cos =1) or 250V/5A (cos =0.4)

Ry3= SPDT(NO/NC) 250V/8A (cos =1) or 250V/5A (cos =0.4)

Relays have one common (C).
Control : by push buttons on the front.
Front : Polycarbonate
Sensor : 2x SM 811/2m (PTC 1000/25C).
Dimensions : 90 x 71 x 58mm (hwd)
Panel cut out : 46 x 71mm (HW) at panel mount
Accuracy : ± 0,5% of the range.

- Provided with memory protection during power failure.

- Connections with screw terminals on the back side.

- Equipped with sensor failure detection.

- Special versions on request available.