VDH ALFA 75-MTT User manual

1
User manual
ALFA 75-MTT
MilkTankThermostat.
VDH doc. 080723 Version: v1.0 Date: 27-05-2008
Software: ALFA75-MTT File: Do080723.WPD Range: 0,0/+80,0C pro 0,1C
*Description.
The ALFA 75-MTT is a Milk tank thermostat with the next functions:
- Cooling: On adjusted set point (f.i. 4,0C).
- Stir: Continuos during cooling and on adjustable intervals when cooling is off.
Manuel stir after pushing the button on the front (with time limitation)
- Temperature alarm: An alarm will be given when the adjusted minimum and maximum temperaturevalues
are exceed. The alarms are reported with an error code on the display, the buzzer will
beactivated andtherelaywill beenergized. A timedelay canbeadjustedfor thealarms.
- Cooling timealarm: Whenthetemperaturedoesn’t reachthetemperature set point within the adjusted time,
an alarm will be given (with buzzer and relay).
- Digital input: If thedigital input is closed during cleaning than thecontrol will stop and the display will
only show the cleaning temperature.
*Installation.
On the connection diagram from the ALFA 75-MTT 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 display will show the measured
temperature.
*Control.
The ALFA 75-MTT can be controlled by four push buttons on the front:
(SET) - viewing / changing from the adjusted value and alarm reset.
(UP) - raise the adjusted value.
(DOWN) - lower the adjusted value.
(STIR) - Start stir manual.
*Normal operation.
During normal operation will the temperature from the temperature sensor be shown. Range 0,0 till 80,0 C.
*Viewing the set point.
By pushing the SET key the set point appears inthedisplay. The led starts flashingto indicate this.
A fewseconds after releasing the SET key the set point disappears and the measured temperature
is shown again.
*Changing the set point.
Push the SET key and the set point appears on 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 temperature is shown again.
*Adjusting internal parameter.
Next to the adjustment of theset point, some internal settings can be madelike differentials, sensor offset and
stir functions.
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 75-MTT changes to it’s normal operation mode.

2
*Parameters ALFA 75-MTT.
Para-
meter Description Parameter Range Default value
01
02
03
04
Switching differential
Minimum adjustable set point
Maximum adjustable set point
Offset temperature sensor
0,1..15,0C
0..+80C
0..+80C
-15,0..+15,0C
0,5
0,0
15,0
0,0
10
11
12
Agitator interval time
Agitator runtime
Agitator delay time
0..60 Minutes
0..240 Seconds
0..900 Seconds
15
120
120
20
21
22
23
24
25
26
30
Minimum Alarm active
Maximum Alarm active
Minimum Alarm-set point
Maximum Alarm-set point
Delay time maximum alarm
Delay time minimum alarm
Cooling time alarm (See description)
Control delay after power up
0=No, 1=Yes
0=No, 1=Yes
0..80,0C
0..80,0C
0..99 Minutes
0..99 Minutes
90..240 Minutes
0..99 Minutes
1
1
0,5
15,0
45
0
120
15
31
32 Cooling on at sensor failure Cooling off at minimum alarm 0=No, 1=Yes 0=No, 1=Yes 0 1
40 Function digital input cleaning
0 = Active when closed (NO)
1 = Active when opened (NC)
0..1 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
-
-
-
-
-
*Sensor adjustment.
The temperature sensor can be adjusted by using the Offset control sensor (parameter 04).
Indicates a sensor e.g. 2C too much, the according Sensor-offset parameter has to be decreased with 2C.
*Error codes.
On the display from the ALFA 75-MTT can appear the following error codes:
E1 - Temperature sensor defect. Solution E1 failure:
- Check if sensor is connected correctly.
- Check sensor (1000/25C).
- Replace sensor..
EEE - Adjustments are lost Solution EEE failure:
- Re-program the adjustments.
LO - Minimum alarm.
HI - Maximum alarm.
AL - Cooling time passed
-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.
*Alarm operation.
If a failure or alarm occurs an error message is shown in the display. The ALFA 75-MTT remembers it’s error
message, although it is already solved. Theerror message can be reset with theSET key.
If after pressing the SET key (=reset alarm) the alarm still is not solved than the ALFA 55-MTT displays the
temperature and theerror messagealternated, is thealarm solved, then theerror messagedisappears and the
temperature is displayed normally.

3
*Agitator control possibilities.
The ALFA 75-MTT has several possibilities to control the agitator.
Normally the agitator is on if the cooling is on. If the cooling switches off the agitator keeps running with the
delay time from parameter 12.
Parameter 10 Agitator interval time:
If the cooling is off, the agitator runs every parameter 10 minutes for parameter 11 seconds.
Parameter 11 Agitatot runtime:
During the interval time the agitator runs for this time.
Parameter 12 Agitator delay time:
If the cooling switches off the agitator keeps running for this time to avoid ice grow on the tank wall.
Adjustable from 0 till 15 Minutes.
It is also possible to start stir manual by pushing theagitator key. Theagitator runs thetimefrom parameter 12
once whereby thenormal control continuos. During the stir timeshows thecontroller remaining stir timeon the
display in seconds and the LED flashes.
*Minimum-, maximum- and cool time alarm possibilities.
The ALFA 75-MTT has a minimum- and maximum temperature alarm and a cooling time alarm;
Parameter 20, 21 Minimum- und maximum alarm active:
With these parameter it is possible to activate the temperature alarm.
Parameter 22, 23 Minimum- and maximum alarm set point:
Withtheseparameters it ispossible to adjust the temperaturealarm set points.
Parameter 24, 25 Time delay for the minimum- and maximum alarm:
Normally there is only a time delay for the maximum alarm and the minimum alarms works without a
time delay. With these parameter it is possible to adjust a time delay for both alarms.
Parameter 26 Cool time alarm:
If thethetemperaturedoesn’t reach theset point within this timean acoustic alarm will begiven and the
alarm relay will be activated.
Parameter 30 Control delay after power up:
To avoid freezing from the first milk in the tank it is possible to adjust a time delay for controln after
power up. The delay times from parameters 24 and 25 are running after the this delay time has ended!
The ALFA 75-MTT has the possibility to take action whan a failure or alarm occurs.
Parameter 31 Cooling on at sensor failure:
When a sensor failure occurs, the cooling will be activated.
Parameter 32 Cooling off during minimum alarm:
Withthis parameter it is possible to switch off the cooling at a minimum alarm. This is to avoid that the
milk will freeze.
*Possibilities for cleaning.
The ALFA 75-MTT has a digital input contact which is programmed as a cleaning contact. Withparameter 40
it is possible to adjust this contact as an opener or closer contact. When this contact is activated stops the
control and the displays shows alternated the cleaning temperature and “SP” to indicate that this function is
active.
Ifcleaningstops(Contactinnormal mode)thecontroller will turninto“Stand-byMode” (Displayviews“Stb”)and
the controller starts working again if the “SET-key” is pushed.
Parameter 40 Digital input contact function:
P40=0 Cleaning function active if input is closed (NO)
P40=1 Cleaning function active if input is opened (NC)
*Technical details.
Type : ALFA 75-MTT Cooling/Agitator Thermostat
Range : 0,0/+80,0C, read out per 0,1C
Accuracy : ± 0,5 % from the range.
Supply : 12Vac/16,5Vdc (-5/+10%)
Relays (with one : Ry-1 Cooling SPST (NO) 250V/8A (cos =1)
Common) Ry-2 Agitator SPST (NO) 250V/8A (cos =1)
Ry-3 Alarm SPDT (NO,NC) 250V/8A (cos =1)
Buzzer : Built in Alarm buzzer
Control : Through push buttons on the front.
Front : Polycarbonate
Sensor : SM 811/2m (PTC 1000/25C).
Digital input : Contact input (Cleaning contact NO oder NC)
Dimensions : 35 x 77 x 71,5mm (hwd)
Panel cut out : 28 x 70mm (hw)
- Provided with memory protection during power failure.
- Equipped with self-test function and sensor-failure detection.
- Connection with screw-terminals.

4
*Dimensions.
*Connections.
*Funktion diagram.
*Addresse.
VDH Products Tel: +31 (0)50 - 30 28 900
Produktieweg 1 Fax: +31 (0)50 - 30 28 980
9301 ZS Roden Email: [e-mail]
The Netherlands Internet: www.vdhproducts.nl