VDH ALFA 33DP User manual

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User manual ALFA 33DP
Min./Max. Alarm thermostat.
VDH doc: 970631 Version: v1.1 Date: 15-06-2001
Software: ALFA 33DP File: Do970631.WP8 Range: -10/+40°C, per 0,1°C
*Installation.
On the topside of the ALFA 33DP you can see how the sensor, power supply and relay has to be
connected.
After connecting the ALFA 33DP to the power supply, a self test function is started. As this test is
finished the measured temperature appears in the display.
The relay alarm is a multi functional combined minimum- and maximum alarm, at alarm the led 'on'
will light-up in the display.
*Control.
The ALFA 33DP alarm thermostat can be controlled by three push buttons on the front;
SET - view / change setpoints and reset of alarm.
UP - increase a setpoint.
DOWN - decrease a setpoint.
*Viewing setpoints.
Viewing setpoint of maximum alarm:
By pushing the SET key first and then the UP key together the maximum alarm setpoint appears
in the display. The led 'set high' starts blinking.
Viewing setpoint of minimum alarm:
By pushing the SET key first and then the DOWN key together the maximum alarm setpoint appe-
ars in the display. The led 'set low' starts blinking.
Afew seconds after releasing the keys the setpoint disappears and the measured temperature is
shown in the display.
*Changing setpoints.
Push the SET key together with the UP or DOWN key and the maximum alarm setpoint or minimum
alarm setpoint appears in the display. Release the both keys.
Now push the SET key again and together with the UP or DOWN keys the setpoint can be changed.
A few seconds after releasing the keys the measured temperature shows again in the display.

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*Action of the alarm functions.
The ALFA 33DP alarm thermostat has a minimum alarm and a maximum alarm both with their own
setpoint. We can choose from two different kinds of alarms (PARAMETER 27) namely:
watchdog alarm (relay normally activated, with alarm it falls off and the led 'alarm' burns. So
on power failure the alarm relay also falls off.)
or a regulated alarm (relay normally not activated, with alarm the relay will be activated and the
led 'alarm' will burn).
With PARAMETER 28 we can choose for a auto reset alarm or a hold alarm after temperature
recovering.
Also its possible to give both setpoints there own offset and differential see function diagram. Each
alarm can be set at an alarm-delay time (PARAMETER 23 and 24) when the temperature will give
an alarm the led 'alarm' first starts to blink. If the temperature will recover within the delay time no
alarm occurs. If an alarm will come through after the delay time the led 'alarm' burns continuously and
thedisplay alternates between the temperature and 'H' for high-alarm (max.) or 'L' for low-alarm (min.)
to indicate the alarm. To reset an alarm press the SET key.
*Setting internal parameters.
Next to the adjustment of the setpoint, some internal settings are possible like differential, sensor-
offset, setpoint range.
By pushing the DOWN key for more than 10 seconds, you enter the 'internal programming menu'. In
theleft display the upper and lower segments 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 and DOWN keys allows you to
change the value of this parameter. If after 20 seconds no key is pushed, the ALFA 33DP changes
to its normal operation mode.
*Sensor adjustment.
Thesensor can be adjusted by using the Sensor Offset (parameter 04). Indicates the ALFA33DP e.g.
2°C too much, the Sensor Offset has to de decreased by 2°C.
*Error messages.
In the display of the ALFA 33DP the following error messages can appear:
Er - Sensor broken. Solution:
- Check if the sensor is connected correctly.
- Check the sensor (1000Ωat 25°C).
- Replace the sensor.
EE - Settings are lost. Solution:
- Reprogramme the settings.

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* Technical details.
Model : ALFA 33DP Alarm thermostat
Range : -10/+40°C, readout per 0,1°C
Supply : 230 Vac (or 24Vdc or 12Vdc)
Relay : SPDT 250V/16A(C-NO), 8A(C-NC) (cos phi=1)
Control : by pushbuttons on the front.
Front : Polycarbonate IP65
Sensor : SM 811/2m (1000Ωat 25°C)
Sizes : 35 x 77 x 71,5mm (hwd)
Panel hole : 28 x 70mm (hw)
- Provided with memory protection during power failure.
- Connection with screw terminals on the backside.
- Equipped with self test function and sensor failure detection.
- Special version are available upon request.
*Parameters ALFA 33DP.
PARA-
METER DESCRIPTION PARAMETER RANGE STANDARD VALUE
04
10
11
21
22
23
24
25
26
27
28
Offset temperature sensor
Startup delay after power failure
Relay on at sensor failure
Differential maximum alarm
Differential minimum alarm
Time delay maximum alarm
Time delay minimum alarm
Offset setpoint High (Max.)
Offset setpoint Low (Min.)
Relay alarm function
(0=watchdog 1=regulated alarm)
Auto reset alarm after temp.
recovering (0=hold)
-15.0..+15.0°C
0..99 min.
0 = No
1 = Yes
0.1..10.0°C
0.1..10.0°C
0..99 min.
0..99 min.
-10.0..+10.0°C
-10.0..+10.0°C
0 = No
1 = Yes
0 = No
1 = Yes
0
0
0
1.0
1.0
0
0
0.0
0.0
0
0
*Address.
VDH Products BV Tel: [phone]
Produktieweg 1 Fax: [phone]
9301 ZS Roden Email: [email protected]
The Netherlands Internet: www.vdhproducts.nl

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*Dimensions.
*Connection diagram.
* Function diagram.