VDH ALFA 71 MODulation User manual

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User manual
ALFA 71 MODulation
Thermostat.
0-100C
VDH doc. 080349 Version: v1.0 Date: 07-03-2008
Software: ALFA71MOD100 File: DO080349.WPD Range: 0/+100,0C
*Installation.
On the top side of the ALFA 71 MOD is shown how the sensors, power supply and relays has to be
connected.
After connecting the ALFA 71 MOD to the power supply, a self test function is started. As this test
is finished the measured temperature appears in the display.
*Control.
The ALFA 71 MOD thermostat can be controlled by four pushbuttons on the front. These keys are:
SET - view / change the setpoint.
UP - increase the setpoint.
DOWN - decrease the setpoint.
C- hidden push button above the SET key and behind Csymbol.
*Viewing set point.
By pushing the SET key the set point appears in the display. The decimal point of the last display
starts blinking. A few seconds after releasing the SET key the setpoint disappears and the
measured temperature is shown again in the display.
*Changing set point.
Push the SET key and the set point appears in the display. Release the SET key. Now push the
SET key again together with the UP or DOWN keys to change the setpoint. A few seconds after
releasing the keys the measured temperature shows again in the display.
*Status of the Relays.
By pushing the hidden Ckey the display shows the status of the relays. Each display segment
shows the status of the relay output, showing 0=off and 1=on. The code 110 means relay 1 and 2
are on and relay 3 is off.
*Readout valve position.
By pushing the UP key the display shows the current valve position.

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*Setting internal parameters.
Next to the adjustment of the setpoint, internal settings can be made like differential, sensor-offset,
setpoint range and the functions of the thermostat.
Push the DOWN key 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 after 20 seconds no key is pushed, the ALFA 71 MOD changes to the normal operation mode.*
Adjustment sensors.
The temperature sensor can be adjusted by using the Sensor Offset parameter 05.
Indicates the Sensor e.g. 2C to much, the Sensor Offset has to be decreased with 2C.
*Error messages.
In the display of the ALFA 71 MOD the following error messages can appear:
LO - Minimum alarm. Solution E1:
HI - Maximum alarm. - Check if the sensor is connected correctly.
E1 - Sensor-1 failure. - Check sensor (1000at 25C).
- Replace sensor.
EEE - Settings are lost. Solution EEE:
- Reprogram the settings.
-L- - In case of sensor short-circuit the display alternates between error-code E.. and -L-,
as indication for a short-circuit sensor.
-H- - In case of open-circuit sensor the display alternates between error-code E.. and -H-,
as indication for a open circuit sensor.
Reset Alarm. When a error-messages appears it can be resetted by pushing the SET key.
The function of this key depends on parameter P37.
*Technical details.
Type : ALFA 71 MOD Thermostat
Range : 0/+100,0C, per 0,1C
Supply : 12Vac 50/60Hz (-5/+10%)
Display : 3-digit 7-segment display
Relays : Ry1= Open SPST(NO)250V/8A (cos =1) of 250V/5A (cos =0.4)
Ry2= Close SPST(NO)250V/8A (cos =1) of 250V/5A (cos =0.4)
Ry3= Alarm SPDT(NO/NC)250V/8A (cos =1) of 250V/5A (cos
=0.4)
Relays have one common (C).
Control : By push buttons on front.
Front : Polycarbonate IP65
Sensor : SM 811/2m (PTC 1000/25C).
Analog output : 0..10 Vdc PI output (cool or heat)
Dimensions : 35 x 77 x 71,5mm (HWD)
Panel cutout : 28 x 70mm (HW)
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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*Parameters ALFA 71 MOD
Para-
meter Description Parameter Range Default
01 Function thermostat 1=Cool
2=Heat 1
02 Offset temperature sensor-1 -15.0..+15.0C0.0
10
11
12
13
14
P-band
I-time
Runtime valve
Reset time
Reset to minimum or maximum valve
position
0,0..+15,0C
0..99 Minutes
0..999 Seconds
0..999 Minutes
0 = mimimum
1 = maximum
5,0
0
120
60
0
20
21
22
Minimum set point
Maximum set point
Read-out above -10C per 1C
0,0..+100,0
0,0..+100,0
0= no, 1= yes
0,0
+100,0
0
30
31
32
33
34
35
36
37
Alarm type
Minimum alarm set point
Maximum alarm set point
Time delay minimum alarm
Time delay maximum alarm
Relay function alarm relay
Reset alarm relay after recovering
alarm
Reset alarm relay after manual reset
0= None
1= Absolute
2= Relative
0.0..+100.0C
0.0..+100.0C
0..99 min.
0..99 min.
0= Watch alarm
1= Control
alarm
0= No, 1= Yes
0= No, 1= Yes
1
0
+100
0
0
0
0
0
40
41 Start up delay after power failure Forced relay function at sensor failure 0..99 Minutes 0= None
1= Min.
2= Max.
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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*Dimensions.
*Connections.
*Address.
VDH Products BV Tel: [phone]
Produktieweg 1 Fax: [phone]
9301 ZS Roden Email: [e-mail]
The Netherlands Internet: www.vdhproducts.nl