VDH ALFA 23 DP User manual

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User Manual
ALFA 23 DP and
ALFANET 23 DP
Minimum / Maximum
Alarm Thermostat.
VDH doc: 072253 Version v1.1 Datum: 28-05-2008
Software: ALFA 13/23/33DP File: Do072253.wpd Range: See product sticker pro 0,1C
* Function.
The ALFA(NET) 23 DP is a digital alarm thermostat for wall and panel mounting. The thermostat
watches the minimum and maximum temperature. The ALFA(NET) 23 DP has one relay for both
alarms. The ALFANET 23 DP has a RS 485 network connection so it can be read out and adjusted on
the Alfanet.
*Installation.
On the topside op the ALFA(NET) 23 DP is shown how the sensor, power supply and relay are
connected.
A few seconds after connecting the ALFA(NET) 23 DP to the power supply, t h e m e as u re d t e m pe ra tu r e
appears in the display.
The alarm relay is a multifunction combined minimum and maximum alarm, at alarm the led 'set high'
will light-up in the display.
*Control.
The ALFA(NET) 23 DP alarm thermostat can be controlled by three push buttons on the front;
SET - view / change set points and reset of alarm.
UP - increase a set point.
DOWN - decrease a set point.

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*Viewing setpoints.
Viewing set point of maximum alarm:
By pushing the SET key first and then the UP key together the maximum alarm set point appears
in the display. The led 'set high' starts blinking.
Viewing set point of minimum alarm:
By pushing the SET key first and then the DOWN key together the maximum alarm set point
appears in the display. The led 'set low' starts blinking.
A few seconds after releasing the keys the set point disappears and the measured temperature is
shown in the display.
*Changing set points.
Push the SET key together with the UP or DOWN key and the maximum alarm set point or minimum
alarm set point appears in the display. Release both keys.
Now push and hold the SET key again and together with the UP or DOWN keys the set point can be
changed. A few seconds after releasing the keys the measured temperature is shown again in the
display.
*Setting internal parameters.
Next to the adjustment of the setpoint, some other internal settings are possible, sensor-offset, relay
function and alarm settings.
By pushing the DOWN key more than 10 seconds, you enter the 'internal programming menu'. In the
left display the upper and lower segments are blinking. With 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(NET) 23 DP changes to
it's normal operation mode.
*Parameter ALFA(NET) 23 DP.
Para-
meter
Description Parameter Range Standard
Value
04 Offset temperature sensor -15.0..+15.0C0.0
10
11
Startup delay after power failure
Relay on at sensor failure
0..99 Minutes
0 = No, 1 = Yes
0
0
21
22
23
24
25
26
27
28
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 temperature recovering
(0=hold)
0.1..15.0C
0.1..15.0C
0..99 Minutes
0..99 Minutes
-10.0/+10.0C
-10.0/+10.0C
0 = No, 1 = Yes
0 = No, 1 = Yes
1.0
1.0
0
0
0.0
0.0
0
0
90
95
96
97
98
99
Network number (Only at ALFANET)
Software version
Production year
Production week
Serial number (x1000)
Serial number (units)
1..250
0..255
00..99
1..52
0..255
0..999
1
-
-
-
-
-

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* Funktion diagram.
*Action of the alarm functions.
The ALFA(NET) 23 DP alarm thermostat has a minimum alarm and a maximum alarm, both with there
own set point. We can choose off two different kind of alarms (Parameter 27) namely:
a watchdog alarm (relay normally activated, at alarm, it falls off and the led 'set high' burns. On
power failure the alarm relay also falls off.)
or a regulated alarm (relay normally not activated, at alarm, it will be activated and the led 'set high'
burns.
With Parameter 28 we can choose for a auto reset alarm or a hold alarm after temperature recovering.
Also it is possible to give both set points 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 passes
the set alarm point, the led 'set high' first starts to blink. If the temperature will recover within the delay
time, no alarm occurs.
If an alarm will continue after the delay time, the led 'set high' burns continuously, and the display
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.
*Adjustment sensor.
The sensor can be adjusted by using the Sensor Offset (parameter 04). Indicates the ALFA(NET) 23
DP e.g. 2C to much, the Sensor Offset has to de decreased with 2C.
*Error messages.
In the display of the ALFA(NET) 23 DP the following error messages can appear:
Er - Sensor broken. Solution:- Check if the sensor is connected correctly.
- Check the sensor (1000at 25C).
- Replace the sensor.
EE - Settings are lost. Solution:- Reprogram the settings.
* Technical details.
Model :ALFA 23 DP Alarm Thermostat
ALFANET 23 DP Alarm Thermostat with Network
Range :-10/+40C, readout per 0,1C(or else see produkt sticker)
Supply :230 Vac / 1,2VA 50/60Hz (or else see product sticker)
Relay :Pot.free contact SPDT 250V/16A(C-NO), 8A(C-NC) (cos phi=1)
Communication :RS 485 Network, 2xtwisted pair shielded, minimum 0,5mm2, maximum
lenght 1KM (A/B/0V, only at ALFANET model)
Control :by pushbuttons on the front.
Front :Polycarbonate IP65
Sensor :SM 811/2m, 2-wire PTC (1000at 25C)
Sizes :144 x 72 x 50mm (hwd)
Panel hole :139 x 67mm (hw), at panel mounting
- 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 on request available.

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