VDH ALFA 72-VS User manual

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User manual
ALFA 72 VS 0-20OC
Differential Thermostat.
VDH doc. 080333 Version: v1.2 Date: 22-04-2010
Software; File: Do080333.wpd Static range (see sticker);
992903 ALFA 52/72 VS 20 -50..+50 Typenr. 904.000702 -50/+50,0C
100320 ALFA 52/72 VS 20 -20..+80 Typenr. 904.000925 -20/+80,0C
992901 ALFA 52/72 VS 20 0..+100 Typenr. 904.000678 0/+100,0C
*Installation.
On the connection diagram of the ALFA 72-VS is shown how the sensors, power supply and relays
has to be connected. After connecting the ALFA 72-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 72-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.
C- hidden key under unit symbol
*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.
Viewing set point delta thermostat:
By pushing the SET key, the set point of delta thermostat appears in the display.
A few seconds after releasing the keys the set point disappears and the differential temperature is
shown again in the display.
*Changing the delta-setpoint.
PushtheSET key.Thedelta-setpointappearsinthedisplay.ReleasetheSET key.NowpushtheSET
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 hidden Ckey 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.

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*Setting internal parameters.
Next to the adjustment of the set point, internal settings can be made like differential, sensor offset,
set point range and the functions of the thermostat.
Push the DOWN key for more than 10 seconds, to 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 key to change the value of this parameter.
If 20 seconds no key is pushed, the ALFA 52-VS changes to the normal operation mode.
*Parameters ALFA 52-VS
Para-
Meter Description Parameter Range Default value
05
06 Offset temperature sensor 1 Offset temperature sensor 2 -15.0..+15.0C -15.0..+15.0C0.0 0.0
10
11
12
13
Switching differential
Switch on delay
Switch off delay
Parameter 11/12 in seconds or minutes
0.1..20.0
0..99
0..99
0 = Seconds
1 = Minutes
0.5
0
0
0
20
21
22
Minimum adjustable delta-setpoint
Maximum adjustable delta-setpoint
Read-out above -10C on whole degrees
0.0..+20.0C
0.0..+20.0C
0= No
1= Yes
0.0
20.0
0
40
41
42
Relay function alarm relay
Reset alarm relay after recovered alarm
Reset alarm relay after manual reset
0= Fail safe alarm
1= Control alarm
0= No
1= Yes
0= No
1= Yes
0
0
0
45
46 Control delay after power failure Relay active at error control sensor 0..99 Minutes 0= Non
1= Relay 1
2= Relay 2
0
0
95
96
97
98
99
Software version
Production year
Production week
Serial number (x1000)
Serial number (units)
0..255
00..99
1..52
0..255
0..999
0
0
1
0
0

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*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.
E2 - Sensor-2 failure. Solution EEE:
EEE - Settings are lost. - Reprogram the settings.
Reset Alarm. Whenanerror-messages appears it can beresetbypushing 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 72-VS.
Type : ALFA 72-VS Differential thermostat
Range : Differential temperature in display: 0/+20C (0,1)
Stactic range : -50/+50,0C, above -10C read-out in 0,1C or
(See sticker) -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 : 12Vac 50/60Hz (-5/+10%) or else see product sticker
Read-out : 3-digit 7-segments display
Relays : Ry1= SPST(NO) 250V/8A(cos =1) of 250V/5A (cos =0.4)
Ry2= SPST(NO) 250V/8A (cos =1) of 250V/5A (cos =0.4)
Ry3= SPDT(NO/NC) 250V/8A (cos =1) of 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.

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* Function diagram.
*Dimensions.
*Connections.
*Address.
VDH Products BV Tel: +31 (0)50 - 30 28 900
Produktieweg 1 Fax: +31 (0)50 - 30 28 980
9301 ZS Roden Email: [email protected]
Nederland Internet: www.vdhproducts.nl